C.A.P.E. ESTUARY MANAGEMENT PROGRAMME · 2020-02-19 · C.A.P.E. Estuaries Programme Eden District...

C.A.P.E. ESTUARY MANAGEMENT PROGRAMME

KEURBOOMS/BITOU ESTUARY MANAGEMENT PLAN

VOLUME IVOLUME IVOLUME IVOLUME I

SITUATION ASSESSMENTSITUATION ASSESSMENTSITUATION ASSESSMENTSITUATION ASSESSMENT

Final Report

Produced by:

Enviro-Fish Africa (Pty) Ltd

22 Somerset Street

Grahamstown

6139

Produced for:

C.A.P.E. Estuaries Programme Eden District Municipality

Pvt Bag X29 P.O. Box 12

Rondebosch George

7701 6530

August 2010

C.A.P.E. Estuaries Management Programme; Keurbooms/Bitou Estuary Management Plan: Situation Assessment

Enviro-Fish Africa (Pty) Ltd.

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TABLE OF CONTENTS

EXECUTIVE SUMMARY iii

LIST OF TABLES, FIGURES & PLATES xxviii

LIST OF ACRONYMS xxx

CHAPTER 1 - INTRODUCTION 1

1.1 Introduction 1

1.2 Terms of reference 1

1.3 Project team 2

CHAPTER 2 - BIO-PHYSICAL DESCRIPTION 3

2.1 Introduction 3

2.2 The extent of the estuarine area 6

2.3 Physical structures 7

2.4 Physical properties 8

2.5 Floods 16

CHAPTER 3 - BIOLOGICAL DESCRIPTION 19

3.1 Flora 19

3.2 Fauna 23

CHAPTER 4 – LEGISLATION AND PLANNING & DEVELOPMENT

STRATEGIES 28

4.1 International obligations 28

4.2 National legislation and policy 28

4.3 Local (Municipal) legislation 33

4.4 Existing management plans, development strategies, policies

and conservation initiatives 34

CHAPTER 5 – RECREATIONAL USE 46

5.1 Exploitation of living resources 46

5.2 Tourism and non-consumptive use 49

CHAPTER 6 - WATER QUANTITY AND QUALITY 51

6.1 Introduction 51

6.2 Management of the catchment 51

6.3 Catchment description 51

6.4 Ecological status 54

6.5 Wetlands 56

6.6 Water quantity 57

6.7 Water quality 58

6.8 Ecological water requirements 59



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6.9 Socio-cultural importance 67

6.10 Pressures/Risk/Threats 67

CHAPTER 7 – CLASSIFICATION, ECONOMIC VALUE,

PROTECTION AND REHABILITATION 68

7.1 Classification 68

7.2 Economic value 69

7.3 Protected area strategy and potential 69

7.4 Restoration/rehabilitation 74

7.5 Climate change 74

CHAPTER 8 - THE WAY FORWARD: OBJECTIVE II 75

8.1 Local estuary management forum 75

8.2 The estuarine management plan 75

8.3 The stakeholder workshop 76

8.4 Issues raised by stakeholders 79

CHAPTER 9 - REFERENCES 81

APPENDIX 1 85

APPENDIX 2 87



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EXECUTIVE SUMMARY

CHAPTER 1 - INTRODUCTION Estuarine ecosystems are not isolated systems. They form an interface between marine

and freshwater systems and are part of regional, national and global ecosystems either

directly via water flows or indirectly through the movement of fauna. In addition to the

biota that these estuaries support, they provide a range of goods and services (uses) to the

inhabitants of the various regions. The interaction between estuaries and users creates a

delicate balance, the sustainability of which needs to be addressed by some form of

management plan.

The urgent need for Estuary Management Plans (EMPs) became apparent during the

development of the Integrated Coastal Management Act (Act 24 of 2008; ICMA), and are

designed to help align and coordinate estuaries management at a local level. Enviro-Fish

Africa (Pty) Ltd. has been contracted by the C.A.P.E. Estuaries Programme to address the

development of an EMP for the Keurbooms and Bitou Estuaries. This report fulfills the

requirements of Objective 1, namely a Situation Assessment.

CHAPTER 2 – PHYSICAL DESCRIPTION

INTRODUCTION

The Keurbooms and Bitou estuaries (collectively referred to as the Keurbooms) are

located close to Plettenberg Bay and both feed into what is known as the Keurbooms

Lagoon, which is separated from the sea by a prominent berm, prior to it flowing out to

sea. The confluence of the Bitou and Keurbooms estuaries is approximately 3.5 km from

the mouth. The Bitou River is 23 km long, with its source at Buffelsnek, and is tidal for

7.2 km from the confluence to the causeway at Wittedrift. The Keurbooms River is

approximately 85 km long, with its source at Spitskop in the Outeniqua Mountains, and is

tidal for approximately 8.5 km from the confluence. The combined catchment has been

estimated at anywhere between 1085 and 1188 km2.

The Keurbooms is a warm-temperate, permanently open, medium-large, Type F barred

system (supratidal barrier), whose ichthyofauna, water quality and aesthetics are rated as

good, good and moderate respectively. The Bitou Estuary above the N2 is characterized

by an extensive floodplain and wetland complex, while the Keurbooms Estuary above the

N2 has no floodplain and is characterized by steep gorges. Extensive intertidal areas,

dominated by sandbanks, mudbanks, saltmarsh and freshwater creeks, characterize both

estuaries below the N2 and the lagoon area. There are two statutory conservation areas

administered by CapeNature, namely the Keurbooms River Nature Reserve and the

Keurbooms River Seagull Breeding Colony. In addition to this, there are significant areas

of private land that are managed for conservation purposes and the Eden to Addo

Corridor Initiative is looking to protect plant and animal habitats through establishing

biodiversity corridors on privately owned land between formally protected areas. Land



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use in the Keurbooms catchment comprises approximately 15% commercial agriculture

and 85% natural shrubland, bushland and forest. Very little (<1%) is degraded or

developed. The upper Bitou catchment comprises mostly State owned indigenous forests;

with the rest of the catchment comprising privately owned land with indigenous forest

and cultivated lands. The lower Bitou catchment comprises mostly farmland, urban

settlements and a sewage treatement works at the head of the Gansevallei.

THE EXTENT OF THE ESTUARINE AREA

The Keurbooms Estuary extends approximately 1.5 km upstream from Whiskey Creek

and the Bitou Estuary extends as far as the causeway over the Wittedrift road. These are

the generally accepted limits, but the exact upper limit of each estuary at any one time

will vary depending on tidal flows in relation to the volume of freshwater entering from

upstream. The seaward extent of the Keurbooms Lagoon is located at the mouth, which

varies according to the location where floods breach the barrier and the subsequent rate of

migration in a SW direction. With regards the terrestrial boundaries, there are several

options commonly used to define the area, namely:

• Floodlines – either the 1:50 or 1:100 year floodlines. These provide a good indication

of the historical extent of floods and therefore areas that pose a risk for developments

and infrastructure.

• 5 m contour – this may be useful in the context of the projected sea level rise and

increase in the severity of floods and storm events due to climate change.

• Coastal protection zone – this zone is defined as a 100 or 1 000 m buffer zone

measured inland from the high water mark and also makes provision for any land

located within the 1:50 year floodline. Essentially, the 100 m zone is defined for areas

zoned as urban and the 1 000 m zone is defined for rural (agricultural) areas. It must

be made clear that these zones are designed to restrict certain activities that may

interfere with the estuary and its sensitive riparian areas, but it does NOT mean that

no activities may take place. Activities that should be restricted, or at least assessed

prior to authorization are those listed in the National Water Act (NWA) that require a

license (e.g. water use), the EIA Regulations and those affecting sustainable

development and sensitive ecosystems These zones do NOT indicate that landowners

may not operate within their boundary, i.e. they do not lose this land, but they must

adhere to sound environmental principles when conducting any activities.

• EIA regulations – although not used to specifically define the estuary area, the 100 m

buffer zone also provides an indication of the area in which listed activities are

regulated relative to the high water mark in accordance with the EIA Regulations.

PHYSICAL STRUCTURES

The road bridge over the Bitou Estuary at Wittedrift and the old causeway immediately

downstream act as obstructions to water flow and essentially form the upper limit of tidal

exchange in the estuary. The existing N2 bridge and embankment obstructs more than

45% of the river width of the Bitou Estuary. A low causeway is present across the Bitou

Estuary approximately 1.5 km upstream of the N2 Bridge. This causes some constriction



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to tidal flows especially at low tides. The N2 bridge over the Keurbooms Estuary does

not appear to affect the orientation of the channel, but may contribute to increased

sediment deposition immediately downstream. There are three picnic sites, administered

by CapeNature, one on the eastern bank and two on the western bank of the Keurbooms

Estuary above the N2 bridge. There is one slipway above the N2 bridge on the

Keurbooms Estuary and seven below the N2 bridge. There are no slipways upstream of

the N2 bridge on the Bitou Estuary and no jetties upstream of the N2 on either the Bitou

or Keurbooms Estuaries. There are two jetties and one boathouse/jetty on the western

side of the Bitou channel below the N2 and a slipway on the eastern side. A single long

jetty extends from Stanley’s Island and a further 4 jetties exist on the eastern side of the

eastern Keurbooms channel below the N2. A small-boat harbour, comprising mooring

facilities for over 100 boats and a slipway are located on the western side below the N2 at

the Plettenberg Bay Angling Club.

PHYSICAL PROPERTIES

DEPTH

The lower reaches of the Keurbooms Estuary is approximately 3 m below MSL and

becomes shallower towards the middle reaches. Upstream of the N2 bridge, average

depth is considerably greater with some sections measuring in excess of 20 m below

MSL. The estuary becomes very shallow at and above Whisky Creek. The depth of the

Bitou Estuary varies between 2.7 m below and 0.7 m above MSL, with the deeper

sections being located upstream of the N2 bridge. Tidal variation inside the mouth is 1.35

m and decreases to 0.95 m and 0.85 m at the N2 bridges on the Keurbooms and Bitou

Estuaries respectively. Although tidal variation occurs throughout the estuarine basin on

the spring tide, active tidal exchange in which the entire water column is flushed occurs

primarily in the lower reaches below the N2 bridges.

There is no record of mouth closure occurring at the Keurbooms Estuary, but the mouth

sometimes becomes very shallow. It is also a matter of concern that the estuary becomes

very shallow at places between the mouth and the N2 bridges, which indirectly could

contribute to mouth closure occurring in the future. A major long-term impact of water

abstraction from the Keurbooms and Bitou estuaries can be mouth closure.

SEDIMENT PROCESSES AND CHARACTERISTICS

The surf zone is the main sediment source for both estuaries, and river floods are

important to temporarily scour open inlets and remove tidal-accumulated sediment from

the lower reaches. The tidal prism of the Keurbooms Estuary is in the order of 1.8 x 106

m3 and the mean spring tidal range in the bay is about 1.6 m. The neap tidal range is very

small in the estuary due to the large accumulation of sand in the tidal inlet. Due to the

constriction of the tidal inlet, the estuary is flood tide dominated. Annually about 1.5 x

104 m

3 of marine sand enters the back-barrier Keurbooms lagoon and the scour by tidal

flows removes enough of the wave deposited sand to maintain the inlet channel and allow

restricted tidal exchange.



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The inlet migrates southwestward by erosion of the southern inlet margin and the growth

of the northern margin. The primary reason for the southwesterly migration of the mouth

is the scouring of the southwest spit that occurs on ebb tides as the flow alters direction to

accommodate the 45º angle of the mouth to the coastline. Several evenly spaced

washover channels are present on the sand barrier and washover sand is an important

local source of marine sand in the estuary. Severe flooding occurs in both systems, with

the most recent in 2007 being the most devastating in living memory. Apart from the

major damage to infrastructure located on the floodplain and scouring of sediment along

the course of the estuaries, floods have a major impact on the mouth in the following

ways:

• The estuary mouth is deepened and widened.

• The normally complex estuary mouth is temporarily straitened.

• Floods are playing a major role in the long-term sediment dynamics upstream of the

estuary mouth. Ongoing inland movement of marine sediments takes place during

periods when only minor floods occur, causing a gradual shallowing of the estuary. In

the long term this ongoing sedimentation is counter balanced by flushing of sediments

during major floods.

TEMPERATURE

There is little evidence of vertical temperature stratification, with surface and bottom

temperatures measuring between 12 and 22.9 ºC. This lower limit is likely to be seen

during coastal upwelling events when cold marine water pushes into the system during

the flood tide. The normal temperature regime, which shows a strong seasonal pattern, is

between 20 and 25oC in summer and 15 and 20

oC in winter. A horizontal gradient exists,

with temperatures increasing upstream. On average the Bitou Estuary is warmer than the

Keurbooms Estuary.

SALINITY

Salinities range from 13 to 35 ppt, with highest salinities in the mouth region. Surface

salinity ranges between 35 and 15.3 ppt and bottom salinities between 35 and 22.6 ppt.

This type of stratification is more evident above the N2 bridges and more pronounced in

deeper areas and over the neap tide cycle; salinity decreases as one moves upstream. On

average, the Bitou Estuary is more saline than the Keurbooms Estuary. Salinity levels

will generally decrease over winter due to increased freshwater runoff. Tidal exchange

occurs throughout the systems, but the entire water column is only flushed each spring

tidal cycle below the N2 bridges.

pH

The pH in the systems ranges from 6 to 8.6 with values decreasing upstream in the

Keurbooms Estuary in lower salinities but showing an increase upstream in the Bitou

Estuary. Riverine water in both systems is slightly acidic due to the leaching of humic

acid.



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DISSOLVED OXYGEN

Dissolved oxygen values in both estuaries may vary between 0 and 11.8 mg/l with the

lowest values being associated with the deeper sections. These low concentrations may

persist in times of prolonged reduced freshwater flow, as inflow is responsible for

flushing these deeper sections.

TURBIDITY

Turbidity is very low, with Secchi disc readings averaging between 1.4 and 1.7 m and

only reduced to < 1 m at times of flooding.

POLLUTION

Sewage

Treated sewage from the Bitou treatment facility (see Figure 2.2) is discharged in the

Bitou estuary via the Gansvlei and Rietvlei wetland systems at the head of Gansevalei,

increasing the flux of nutrients into the system. Most of the treated sewage is currently

used to irrigate existing golf courses and polo fields and it is expected that the demand for

treated sewage will grow. There is, however a risk of untreated sewerage entering the

system either due to failed infrastructure or floods scouring through the treatment works.

Industrial

No industrial activities take place in the catchment of the Keurbooms or Bitou Rivers.

Metals

Concentrations of elements in water samples are considered average for similar

southeastern Cape rivers, with the exception of lead and cadmium, which are elevated.

No source could be identified and it is thought they may be of geochemical origin. Metals

in surface sediments are considered average, but on average were slightly elevated in the

Bitou when compared to the Keurbooms, possibly due to mineralisation in the catchment.

Concentrations were elevated in the vicinity of the Plettenberg Bay Angling Club marina

on the Keurbooms, most likely as a result of spills and human activity. The southwestern

arm of the lagoon close to Poortjies and Plettenberg Bay exhibited elevated levels due to

contaminated urban runoff.

FLOODS

FRESHWATER FLOODS

The Keurbooms and Bitou systems are prone to episodic flooding that has catastrophic

consequences for landowners and infrastructure and also poses a risk to human safety.

Floodwaters cause extensive erosion, particularly in the lower reaches where land has

been cleared to make way for residential developments and resorts. The removal of

riparian vegetation weakens the banks’ stability causing it to be undercut and ultimately

collapse into the estuary. The effects of these floods have been exacerbated in recent

times by the accumulation of debris in the catchment, mostly from forestry and alien

clearing projects. The greatest damage occurs in the Keurbooms system below the N2

bridge, as this is where the most development has occurred and where vegetation has



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been cleared. However, most structures adjacent to the estuary are affected to some

extent. The Bitou floodplain suffers less direct structural damage to infrastructure and

land, but dwellings are still prone to flooding.

MARINE (STORM) FLOODS

Flooding from the seaward side during extreme storm events can also cause widespread

damage to property, infrastructure and the banks of the estuary that have been

destabilized by developments.

RECOMMENDATIONS

The following recommendations can be considered:

• No new developments within the risk area – this could be the 1:100 year floodline or

below the 5 m contour.

• Planting of vegetation along the estuary banks where it has been cleared.

• Clearing of debris from the catchment by forestry and those responsible for alien

clearing.

• Bank stabilization to repair existing damage and to minimize impacts from future

events. Attempts to stabilize the banks in the lower reaches of the Keurbooms have

met with varying levels of success and the EMP will attempt to establish a protocol

for best practice based on existing technologies and past successes. In addition, the

authorization process needs to be revisited to account for landowners needing to carry

out repairs after each event without having to undertake the EIA process each time.

CHAPTER 3 – BIOLOGICAL DESCRIPTION

FLORA

MICROALGAE

An increase in freshwater input causes a decrease in mean salinity, an increase in the

horizontal gradient and an increase in nitrate and chlorophyll-a concentrations. This

indicates that freshwater inflow stimulates microalgal growth and therefore primary

productivity. Benthic microalgal biomass ranges from 106 – 191 mg/m2 for intertidal

sites and from 257 to 640 mg/m2 for subtidal sites. Intertidal benthic microalgal biomass

has been recorded between 9.53 ± 0.78 µg/g1. This value is low when compared to other

permanently open estuaries sampled and is related to the sandy nature of the estuary and

low sediment organic content compared.

MACROALGAE

Submerged macrophytes

Zostera capensis is the dominant submerged macrophyte in the Keurbooms Estuary and

Ruppia cirrhosa is the dominant form in the Bitou Estuary. Although Ruppia has a wide

salinity tolerance range (0-75 ppt), it does not survive in the lower reaches since it has

relatively weak stems that break in the presence of strong currents. Very little Z. capensis

was found in the Bitou Estuary above the N2 bridge because of reduced tidal action

caused by physical obstructions.



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Emergent macrophytes

In the Keurbooms Estuary, reeds and sedges are limited to the supratidal marshes and

areas of freshwater inflow. The Bitou Estuary is characterized by dense monospecific

stands of Schoenoplectus scirpoides and Phragmites australis within the channel because

of the low flow and restricted tidal action.

Intertidal saltmarsh

The dominant intertidal salt marsh species in the Keurbooms are Spartina maritima,

Sarcocornia perennis and Sarcocornia decumbens. Salt marshes are not extensive in the

Keurbooms Estuary due to the geomorphology of the system. The Bitou Estuary has a

wide floodplain connected to the estuary by numerous tidal creeks. The largest areas of

salt marsh occur on these floodplains.

Supratidal saltmarsh

The elevated areas of the floodplains are covered with supratidal salt marsh vegetation,

mainly Sarcocornia pillansii. The largest supratidal salt marshes are found on the

floodplain of the Bitou Estuary. Mats of grasses such as brakgras and seaside quick

dominate large sections of the disturbed upper marsh in both the Bitou and Keurbooms

estuaries. The fringes of the floodplains are occupied by reeds, rushes and sedges, which

are an indication of freshwater inflow.

Terrestrial plants

The terrestrial vegetation in the middle and lower reaches can be grouped into five types,

namely primary dune scrub, secondary dune scrub, hind dune scrub, fynbos and aliens.

The upper reaches are characterized by dense indigenous forest interspersed with alien

trees. Alien tree species are invading the floodplain areas of the Bitou and Keurbooms

Estuaries, and infestation is also a problem within the entire catchment/riverine area.

THE BITOU FLOODPLAIN/WETLAND COMPLEX The Bitou wetlands located between the N2 road/bridge and the Bosfontein River are one

of the last undeveloped floodplains along the Western Cape coast and comprise a series

of typical open freshwater marsh systems, supra- and inter-tidal saltmarsh, river channels

and the Bitou Estuary channel itself. Floods are episodic, usually occurring in

spring/early summer and are vital for maintaining ecosystem functioning in combination

with the twice-daily tidal cycles. The Bitou wetlands are the most valuable ecological

resource of the entire catchment, and are currently under severe threat of development on

its perimeter. The wetland corridor provides a link between the SANParks Forest Reserve

and the Keurbooms Nature Reserve and potentially allows for the movement of species

between protected areas.

Floodplain saltmarsh areas are dominated by Sarcocornia perennis while riparian areas

comprise mostly reeds and sedge. Upstream of the causeway, the riparian vegetation

comprises indigenous milkwoods and some yellowwoods. The floodplain in the upper

reaches also comprises scattered concentrations of rush. The terrestrial portion of the

Bitou Valley comprises fynbos associated species, Valley Thicket and Knysna



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Afromontane Forest. Numerous shallow open pans are scattered on the floodplain and are

considered an important habitat for birds.

The Rietvlei wetland system is a complex of seasonal and permanent vegetation

including S. littoralis, Bulboschoenus maritimus, Typhus sp. and aquatic grasses.

Baillon’s crake, which is a Red Data species, is known to breed here and other rare birds

such as the redchested flufftail, African rail, black crake, purple gallinule and purple

heron are common residents. Areas characterized by temporary pools and short grasses

are dominated by small waders, ducks, spoonbills and ibis.

Large areas of the floodplain are used for grazing cattle, but this is not intensive, and

vegetation cover and riparian cover are maintained so that erosion and bank

destabilization (also from trampling) is not a concern. Cows access the water to drink

when it is not too saline. There are several access roads through the floodplain on private

property and although it is unknown whether these have an adverse affect, it is unlikely

as they do not block drainage channels and still allow free movement of water.

The Gansvlei/Diep River/Rietvlei system of rivers and wetlands serve to filter and further

purify the treated effluent from the Bitou Sewerage Works located at the head of

Gansevalei. The maintenance of these wetlands as a buffer is important if water quality

entering the Bitou Estuary is to be maintained at an acceptable level.

The land on the northern side of the Bitou Estuary is currently still being used for grazing

and does not appear to have been severely degraded. Meetings with current landowners

revealed that they feel they look after the area already and do not need a conservancy to

facilitate a management function they already fulfill. A recommendation may be to fence

off sensitive areas to prevent damage to vegetation by grazing and trampling, but this will

need to be done in cooperation with the private landowners. In addition, the Eden to

Addo initiative to establish the Bitou Corridor linking the SANParks and Keurbooms

protected areas needs to be considered in cooperation with landowners.

FAUNA

Zooplankton

Zooplankton displays high species richness in the Keurbooms Estuary, with 39 species

being recorded and a dry biomass of between 2.9 to 108 mg/m3. Pseudodiaptomus hessei

is the dominant copepod and is particularly abundant in lower salinity waters above the

N2 bridge in the Keurbooms.

Benthic invertebrates

The largest proportion (42 taxa) of the invertebrate fauna is either benthic or associated

with the aquatic vegetation. The benthic fauna is well developed from the lower reaches

to the middle reaches, with sandprawn, bloodworm, pencilbait and mudprawn being the

dominant forms. Mudprawn and sandprawn together contributed more than 50% (26

tonnes) of the standing stock of benthic organisms in the Keurbooms Estuary. The sand

mussel and the echinoids Echinodiscus bisperforatus (pansy shell) and Echinocardium



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sp. also burrow the sand in the area proximal to the mouth. The largest and most closely

spaced mudprawn population occurs in the Bitou Estuary, where muddier sediments are

present. Macro-invertebrates such as Nassarius, Natica and Diogenes are common on the

mid and distal flat areas while the mud crab is common amongst saltmarsh vegetation and

Zostera beds. An abundance of crabs, either Sesarme castenata or Cleistostoma

edwardsii are present amongst the mud and creek vegetation of Gansvlei.

An important component of the soft sediment community is the pansy shell. Of the three

main populations of pansy shell in South Africa, two are within Plettenberg Bay. One of

these is located along Keurboomstrand and in the lagoon in the vicinity of the mouth near

the caravan park. The limited distribution and high souvenir value have resulted in the

species being classified as endangered in South Africa, and protected by the Sea Fisheries

Act.

Amphibians and reptiles

Fourteen amphibian species, twenty-seven snake species, three species of tortoise and

one terrapin species are likely to be associated with the Keurbooms and Bitou systems.

Freshwater fish

The Keurbooms redfin is an endangered species found in the Kransbos, Diep and

Langbos rivers of the catchment and has been identified as requiring special conservation

attention. In addition, the following indigenous species are known to occur; forest redfin,

Cape galaxias, Cape kurper and longfin eel. Alien species include rainbow trout, brown

trout and large-mouth bass. Two marine-migrant species, namely Cape moony and

freshwater mullet have been found in the riverine region above the estuary.

Marine and estuarine fish

A total of 29 species of fish have been recorded in the Bitou and Keurbooms Estuaries,

with the Mugilidae (5 species), Sparidae (4 species) and Gobiidae (4 species) dominating

the catch. The Cape stumpnose is numerically dominant followed by juvenile mullet.

Dusky kob dominates the community in terms of biomass followed by the mullet Liza

richardsonii. The fish fauna is dominated by marine-migrant species (utilize estuaries but

spawn at sea), with a large juvenile component mostly occurring below the N2 bridges,

reflecting the importance of these systems as a nursery area. In addition to dusky kob,

both systems are home to other important and over-exploited linefish species such as

white steenbras, spotted grunter and leervis. The Knysna seahorse is known to occur and

is listed as an Endangered species on the IUCN Red List due to its fragmented

distribution, small area of occupancy, the vulnerability of its habitat and susceptibility to

high mortality due to freshwater flooding. There is an hypothesis that the Knysna

population may be the source of new colonists for the Keurbooms after flood events and

that the system is merely a temporary habitat for the species at times when conditions are

favorable. Research is urgently required to determine whether the Keurbooms population

is permanent.



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Birds

A total of 64 species, totaling 31 051 individuals have been recorded over the 13 year

period by the Coordinated Waterbird Counts (CWAC) programme. The kelp gull is by far

the most dominant species, followed by the swift (great crested) tern, grey plover, reed

cormorant, curlew sandpiper, sacred ibis and common whimbrel. Two pursuit-swimming

piscivores, namely the white-breasted cormorant and the Cape cormorant, which are

capable of feeding on up to 16% of their body weight daily, also occur in moderate

numbers. A total of 503 of the endangered African black oystercatcher have been

counted.

The most birds were counted in January 1997, with 2 072 individuals being recorded,

followed by January 1996 (1 695), February 2002 (1 569), January 2005 (1 519) and July

1996 (1 365). Counts over summer months always exceed those in winter of the same

year due to the influx of summer migrants. In summer the avifauna is dominated by

migratory waders, gulls and terns. The remaining avifauna includes a variety of wading

birds (particularly Sacred Ibis and Reed Cormorant), resident waders, cormorants and

small numbers of waterfowl. In winter, numbers are dominated by terns, gulls and

wading birds (particularly Reed Cormorant and Sacred Ibis. About 12% of migratory

waders remain in winter.

A report based on CWAC counts between 1992 and 1997 stated that bird species

numbers and total counts for the Bitou Estuary had been on the decrease and this was

attributed to pollution from effluent, pesticides and fertilizers, damage to habitat by

livestock, siltation of the estuary, reed encroachment and residential development. The

lower Bitou River includes excellent marsh habitat for rails and other secretive birds, and

redchested flufftail and Baillon's crake may breed in this area. Moorhen counts peak in

winter although recorded numbers are decreasing; winter Dabchick counts are also

decreasing. The area is important for foraging and roosting shorebirds, waterfowl and

egrets. The Bitou wetlands system is considered vital from a bird (breeding and

biodiversity) point of view and is need of protection.

The Keurbooms River Seagull Breeding Colony located along the barrier in the lagoon

area has the largest breeding colony of kelp gulls in the region, with approximately 1450

breeding pairs recorded in 2003. In addition, the African black oystercatcher and several

tern species are also thought to breed and roost within the sanctuary.

Mammals

Common mammals that may be spotted within the Keurbooms Nature Reserve and in

close association with the estuaries include the bushpig, dassie, caracal, genet, baboon,

vervet monkey, blue duiker, bushbuck, grysbok, leopard, mongoose and the Cape

clawless otter.



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CHAPTER 4 – LEGISLATION AND PLANNING &

DEVELOPMENT STRATEGIES

The purpose of this section is to review all forms of legislation that may have an impact

on the management of the Keurbooms and Bitou Estuaries. This review incorporates

international agreements and strategies as well as all forms of national, regional and local

legislation as well as municipal planning and development strategies, and other

conservation or development framework initiatives. The details will not be reproduced in

the executive summary and can be viewed in Chapter 4 of the main Report.

CHAPTER 5 – RECREATIONAL USE

EXPLOITATION OF LIVING RESOURCES

KING ET AL.

A survey revealed the following about the fishery on the Keurbooms and Bitou Estuaries.

• The fishery is male dominated and comprised 68% whites, 38% coloured and 1%

black.

• 48% of the participants live within 30km of the estuaries.

• Recreational shore-based anglers comprised 46% and boat-based anglers 52%; only

2% were classified as subsistence.

• 86% of anglers were not affiliated to any club.

• Subsistence anglers fish for substantially longer periods per outing than shore- or

boat-based anglers. 42% of anglers undertake night-fishing outings as well.

• Effort is higher on weekends and public holidays for recreational anglers but no

difference was noted for subsistence users.

• Effort was highest below the N2 road bridges for all sectors, with the confluence

region being a key focal point.

• Catch per unit effort (Cpue) was highest for boat-based anglers (0.07

fish/angler/hour) followed by subsistence anglers (0.03) and shore-based anglers

(0.02). Overall average cpue was 0.04 fish/angler/hour and total estimated harvest for

the survey period was 19 452 fish (6 573 kg).

• Only 32% of anglers catch at least one fish per outing and only 4% ever attain or

exceed the bag limit for a species.

• Fourteen species were recorded in catches, of which Cape stumpnose was

numerically dominant followed by spotted grunter and white steenbras. Spotted

grunter dominated the catch by weight.

• The majority of fish caught were under the minimum legal size.

• 59% of anglers use bait collected exclusively from the estuaries; 13% use bait

collected and bought from retailers; 21% use bait exclusively bought from retailers;

4% used bait bought illegally from subsistence collectors and 3% used artificials.

• Most commonly used bait includes sandprawn, pilchard, mudprawn and pencil bait.

The estimated harvest for sand and mudprawns over the survey period was 199 891

and 185 742 respectively.



xiv

• Angler perceptions were that abundance and mean size of bait organisms has

declined, with 30% attributing this to over exploitation.

• Knowledge of bait and fish regulations was poor.

• Compliance monitoring effort appears to be low, with 72% of anglers never having

had their catches inspected. The frequency of inspection for 34% of those who have

been monitored is less than once in every 50 outings.

• 74% of anglers thought catches had decreased over time (catch rate and average size)

with A. japonicus, P. commersonnii and L. lithognathus being the most noteworthy.

• The high percentage of undersize fish kept by anglers was viewed as a major concern,

and an increase in compliance monitoring efforts combined with an awareness raising

campaign is strongly motivated.

ANECDOTAL INFORMATION

• The fishery is diverse, comprising shore and boat-based anglers using a variety of

gear types.

• Up to 30 power driven boats may be active on the estuary per day during the year, but

during holiday season this may increase to between 300 and 400.

• There are between 30 and 40 rowing boats used by fishermen mainly from New

Horizons with effort concentrated in the lagoon area.

• It is estimated that in excess of 150 and 100 anglers from New Horizons and

Wittedrift respectively fish in the two estuaries and lagoon. Effort is divided between

day and night and weekends (dependant on employment) and between the estuaries

and the sea depending on where fish are being caught. Sandprawn, mudprawn and

pilchards (bought) are the dominant bait items.

• Most effort is during daylight hours and below the N2 bridges.

• Many anglers admit to keeping undersize fish as this is a primary food source.

• More dusky kob is being caught than previously due to use of artificials, particularly

in upper reaches above Whisky Creek.

• Juvenile leervis are present in catches all year, with larger specimens in

February/March. Elf are present between November and April.

• Predominantly juvenile white steenbras are caught in the estuary.

• There is a consensus that fishing has improved since the 2007 floods and that this was

good for the system.

• Illegal bait collecting methods (digging) is not prevalent, but illegal selling does take

place.

• A charter operation takes clients fishing and promotes a catch-and-release ethic.

• The availability and proposed price increase of recreational licenses was viewed as

problematic and in need of attention.

• Education and awareness programmes are required to inform users about regulations

and the importance of the estuaries in general.

• Conflict between user groups is not considered to be a major concern.

• No-take sanctuary zones were recognized as important but site selection needs to be

based on sound scientific data.

• No fishing competitions take place on the estuary and stakeholders felt that this

should not change.



xv

LICENSED SUBSISTENCE FISHERS

There are 65 subsistence exemptions (permits) that have been granted to fishers in The

Craggs for the year 2010. The permit does allow for the sale of certain fish species but

does not allow for the sale of bait organisms. For the most part these fishers fish in the

marine environment. According to MCM there are no subsistence permits granted to any

fishers residing in the communities (e.g. Wittedrift and New Horizons) close to

Plettenberg Bay.

TOURISM AND NON-CONSUMPTIVE USE

A host of non-consumptive activities take place primarily on the lagoon and Keurbooms

Estuary; the Bitou Estuary is not easily accessible by boat above the N2 bridge.

Plettenberg Bay and its surrounds are one of the major tourist destinations in South

Africa, and yet despite this, the Keurbooms is not specifically marketed as a tourist

destination. Several resorts are available to the tourist and numerous B&Bs and

guesthouses also provide accommodation. Many tourists own property close to the

estuaries and are frequent visitors throughout the year. There are also a large proportion

of permanent residents who choose to live here.

Activities that take place include:

• Appreciating nature – includes rest and relaxation, swimming, walking, canoeing,

power boating, bird watching and picnics. Guided tours with an educational slant are

offered on board two motorized barges.

• Water sports – predominantly water skiing above the N2 bridge on the Keurbooms

Estuary. Kite boarding, windsurfing and sailing may also take place.

• Sporting events – although the SA National Canoeing Championships have been held

on the Keurbooms there is considerable potential for it to host additional events such

as open water swimming, rowing and sailing (in the lagoon area).

Potential activities identified during stakeholder meetings include:

• Formal walking trails through the Keurbooms Nature Reserve.

• Educational workshops for school groups to create an awareness of estuaries.

• Snorkeling trails linked to the Knysna seahorse.

• Additional organized sporting events.

• Package holidays that include a variety of activities associated directly or indirectly

with the estuaries.



xvi

CHAPTER 6 – WATER QUANTITY AND QUALITY

MANAGEMENT OF THE CATCHMENT

The Keurbooms/Bitou catchment’s management structures consist of a number of

national, local and municipal structures. These include the National Department of

Environmental Affairs, inclusive of the Directorate Marine and Coastal Management, the

Provincial Department of Environmental Affairs and Development Planning, the National

and Provincial Department of Water Affairs, other National and Provincial offices of

departments/directorates, e.g. Agriculture, Forestry, Tourism and Land Affairs, and the

Bitou Municipality within the Eden District Municipality.

CATCHMENT DESCRIPTION

The Keurbooms and Bitou river catchments are located in the Gourits Water

Management Area (WMA) 16. The catchments of these two rivers have been measured at

between 1 085 and 1 270 km2, with the Keurbooms being estimated at 70 km in length

and the Bitou River at 23 km. The rivers drain the K60 catchment, which includes

quaternary catchments K60A, B C, D, E and F. A small tributary which falls within

K60G also forms part of the Bitou catchment, and flows directly through the Plettenberg

Bay Sewage Treatment Works (STW) at Gansevalei. It should be noted that the Piesang

River also forms part of K60G, but forms part of an independent catchment and estuary

and not part of this study.

Plettenberg Bay receives rainfall all-year-round with peaks in autumn (March/April) and

spring (August to November. The higher rainfall for Plettenberg Bay in spring (dominant

rainfall period) is a product of the late winter frontal systems together with the effect of

orographic rain resulting from the proximity to the coastal mountains. The rain is mainly

cyclonic and orographic, while thunderstorms are rare. Winter rainfall is associated with

the increase in cold fronts (east moving cyclones) passing over the coast.

The only major dam in the catchment is the Roodefontein Dam, which was raised to

2x106 m

3 capacity in 2003. Environmental releases of 0.31x10

6m

3 are made from this

dam to meet requirements at IFR5 downstream of the confluence of the Keurbooms and

Palmiet rivers. Farm dams are mostly situated in the Upper and Lower Keurbooms River

and Piesang River. The Bitou Municipality’s water sources are shown in the table below.



xvii

Town Current source of supply Future source of supply

Plettenberg Bay Pumping from the Keurbooms River, just below the

confluence with the Palmiet; Roodefontein Dam (also

irrigation abstraction for Jakkalsdraai); and six inland

boreholes (although saline intrusion limits use).

Off-channel storage adjacent to Keurbooms River.

Raise Roodefontein Dam + increase pumping from

Keurbooms during high demand periods.

Keurboomstrand Keurbooms aquifer via wells and boreholes. Off-channel storage in Matjies River. Share of Bufels

River Dam. Obtain water directly from Plettenberg Bay

works.

Kurland Small pool in Wit River, run-of-river abstraction. Unknown

Nature’s Valley Natural pool in Groot River; run-of-river pumping

scheme.

Unknown

Land-use in the upper catchment is predominantly natural forest, mountain fynbos and

grasslands, while the middle and lower catchments are used more extensively for

agriculture, residential and recreational purposes. No significant increases in irrigation,

forestry or farm dams are expected up to 2025.

ECOLOGICAL STATUS

RIVERS

Biological monitoring activities of the Keurbooms and Bitou rives were undertaken as

part of a provincial initiative between DWA and CapeNature in order to fulfil the

objectives of the national River Health Programme (RHP). The information products

generated by the RHP assist in distinguishing between aquatic ecosystems exposed to

sustainable utilization and those experiencing ecological deterioration. It also allows for

subsequent audits of management strategies and actions implemented to improve or

maintain the ecological status of aquatic ecosystems. The RHP determines the ecological

state of river ecosystems in South Africa by evaluating physical drivers such as

geomorphology, water quality and habitat integrity, as well as biotic indicators such as

fish, macroinvertebrates and riparian vegetation. Results of the monitoring activities at

two sites are presented below.

Keurbooms River RHP site: K6KEUR-RHINO

• Macroinvertebrates: This site is characterized by a high species diversity, with a high

sensitivity score. The results show that this site is in a Natural condition.

• Geomorphology: The Geomorphological Index (GI) shows that this site is in a C

category in terms of its geomorphological state. Clearing the recruits of black wattle is

needed and would require effective management.

• IHI: A number of abstraction pipes were seen at the site, with serious modifications to

the non-active channel. A large portion of the left-hand bank has been modified. A

moderate infestation of alien vegetation was seen in the riparian zone.

Bitou River site: K6BITO-WITTE

• Macroinvertebrates: Analysis not undertaken as suitable biotopes were not available

for sampling.



xviii

• Geomorphology: No results shown.

• IHI: Modification of flow evident by two water abstraction devices and two bridges.

The riparian zone appeared highly susceptible to erosion.

WETLANDS

A large number of freshwater wetlands are found within both the river catchments, with

58 wetlands having been surveyed. Storage in farm dams and direct abstraction for fruit

farming, pasture cultivation, forestry and alien plant infestations, have resulted in the

degradation of several wetlands. These impacts have also resulted in the disturbance of

the riparian zones within the catchments.

Quaternary catchment K60D was rated as having the highest number of wetlands and

river-associated riparian systems that remain in a good condition, while K60E was the

poorest with a large plantation block (Keurbooms State Forest) being cultivated directly

within the wetlands, and resulting in eroded areas. As catchment K60D is the principal

water source for the Keurbooms and Bitou Estuaries, the maintenance of its wetlands are

of paramount importance. The largest wetlands are found within K60F, i.e. the Bitou

catchment.

WATER QUANTITY

Thirteen gauging stations or plates have been used to record flow data for various periods

starting in 1961. These are mostly located along the upper and lower reaches of the

Keurbooms River. Peaks in run-off volumes are evident throughout the year. Although

the estuary is flood tide dominated, with the scour by tidal flows removing wave

deposited sand to maintain the inlet channel and allow tidal exchange, river floods also

have an important function. Past studies have noted that the Mean Annual Runoff (MAR)

of the Keurbooms River was highly variable and mirrors rainfall in the region. However,

all studies agree that the lowest runoff is recorded at times when the water demand is

highest.

Instream Flow Requirements (IFR), i.e. the flow portion of the Ecological Reserve (or

Ecological Water Requirements), for the Keurbooms Estuary were estimated at

approximately 144 x 106 m

3 per annum or 77% of the present day MAR estimated in

1999 at the estuary. A conservative approach was followed due to the paucity of

information, with results indicating that the estuary required 100% of present day flows.

These figures were updated during the Rapid Reserve study of 2007.



xix

ECOLOGICAL WATER REQUIREMENTS

BACKGROUND

The NWA (Chapter 3, Part 3) provides for the protection of significant water resources

through the Reserve. The Resources Directed Measures (RDM) Directorate is the Chief

Directorate within DWA tasked with the responsibility of ensuring that Reserve

requirements, which have priority over other uses in terms of the Act, are determined

before licensing applications can be processed, particularly in water-stressed

catchments. Reserve determinations can be conducted at a Desktop, Rapid, Intermediate

or Comprehensive level. Each level of determination entails a more detailed (higher

confidence) investigation than the previous level. These determinations have to take place

before the water allocation process (compulsory licensing) can proceed. Once Reserve

requirements are available, the allocable resource could be determined and water use

applications evaluated. This means that human (Basic Human Needs Reserve) and

ecological requirements (Ecological Water Requirements, EWR, or the Ecological

Reserve) need to be met before flow can be harnessed for other users.

One of the first steps of the Ecological Reserve process is Ecological Classification. This

step refers to the determination and categorization of the Present Ecological State (PES)

of various biophysical attributes relative to the natural unimpacted reference condition.

Once the PES of these variables has been determined, the EcoStatus is assigned

according to the classification shown in the table below. Once the EWR has been

determined, the estuary will be assigned a Recommended Ecological Category (REC),

which is the state that should be achieved via management interventions.

KEURBOOMS ESTUARY RESERVE ASSESSMENT

A Rapid (desktop) Reserve determination was conducted for the Keurbooms Estuary

consisting of the Keurbooms and Bitou river arms in 2007. For the purposes of the

Reserve study, the geographical boundaries of the estuary were defined as follows:

• Downstream boundary: Estuary mouth (34° 2'31.99"S, 23°23'2.53"E);

• Upstream boundary – Keurbooms arm: Approximately 12.5 km upstream of the

mouth (33°57'8.04"S, 23°24'6.51"E);

DEVI ATION FROM

REFERENCE CONDITIONSA- F CATEGORIES SCORE

A ? 92.01

A/B >87 .4 and <92.01

B 8 2.01 – 87 .4

B/C >77 .4 and <82.01

C 6 2.01 – 77 .4

C/D >57 .4 and <62.01

D 4 2.01 – 57 .4

D/E >37 .4 and <42.01

E 2 2.01 – 37 .4

E/F >17 .4 and <22.01Serious change

No cha nge

Small change

Moderate change

Large change



xx

• Upstream boundary – Bitou arm: Approximately 12.8 km upstream of the mouth

(33°59'58.44"S, 23°20'27.49"E); and

• Lateral boundaries: 5 m contour above mean sea level along the banks.

The Rapid Reserve study relied on existing data and no new data were collected. The

accuracy of the study depends largely on the accuracy of the simulated runoff data and

measured flow data. River flow data from the Keurbooms River were available from

November 1997. The overall confidence in the hydrological data provided to the study

team was considered to be Medium.

The Estuarine Health Index (EHI) score for the estuary indicated that the estuary’s PES is

in an A/B Category. The estuary has been identified as important from a biodiversity

conservation point of view and is listed as a Desired Protected Area in the C.A.P.E.

Estuaries Conservation Plan. It should therefore be managed as a Category A system, i.e.

the REC should be A. However, the system cannot be rehabilitated to a Category A due

to the pressures contributing to the present state of the estuary. Thus, Category A/B,

representing a largely natural state, was considered to be the REC.

The quantification of Ecological Reserve Scenarios was undertaken as part of the Reserve

assessment (see table below). The evaluation of the simulated runoff scenarios was used

to derive the REC, which was defined as the runoff scenario that represents the highest

reduction in river inflow that will still protect the aquatic ecosystem of the estuary and

keep it in the required category. In evaluating Future Scenarios 1 to 4 it was assumed that

only river inflow from the Keurbooms catchment will be reduced and that all other

related anthropogenic activities (e.g. fishing, bait collection, power boating and human

disturbance) will remain at present levels. Taking the above into account, Scenario 1 was

selected as the REC for the Keurbooms Estuary as this scenario will maintain the

estuary in an A/B category with less impact on the environment (with only 8 % of the

MAR reduced from reference state), while allowing some use of the estuary.



xxi

The estuarine specialists who were a part of the Reserve study team also concluded that

Future Scenario 2 probably does not pose a serious risk to the health of the

Keurbooms/Bitou Estuaries, but that more data will be required over the next few years

to increase the overall confidence in the study.

PRELIMINARY RESERVE TEMPLATE (APRIL 2010)

The draft Preliminary Reserve template (see below) was obtained from Chief Directorate:

Resource Directed Measures (CD: RDM) at DWA in April 2010, and conditions and

background are shown below. Note that upon completion, these values will be signed by

the Chief Director of the CD: RDM, and Gazetted for implementation to manage the

Keurboom and Biotu Estuaries.

*Keurbooms Estuary includes both the Keurbooms and Bitou systems.

To meet the EWR, there had to be some assumptions and limitations on the hydrology.

There was an agreed interim requirement that the diversions be reduced or stopped when

the river flow decreases below 0.3 m3/s and the diversion capacities were reduced by a

22/24 hour factor to account for breakdowns or power supply. It was also proposed that

the river inflow to the Bitou Arm of the Keurbooms system should remain similar to the

present state because: the Bitou Arm comprises an important, ecologically sensitive

wetland; the baseflows from the Bitou River are very low and it would be very easy to

remove all flows to the Bitou Arm of the estuary; the upper part of the Bitou Arm is very

narrow and shallow and potentially very sensitive to changes in flows; and due to the

Na me De scription

Keurbooms

MAR

(MCM/a)

Bitou

MAR

(MCM/a)

Combine d

MAR

(MCM /a)

% natural

M AR PES

Re ference Reference Con dition 174 58 232 100% A

PresentPresent State, including a diversion of 0. 1 m

3/s

to Pletten berg Bay164 51 215 92.70% A/B

Future

Scenario 1

As at Present State but the diversion is

increased to 0.45 m3

/s , no off-channel

s tora ge, 0. 145 m3

/s to Roode fontein,

include Rive r EWR

1 63 5 1 214 92. 20% A/ B

Future

Scenario 2

As at Present Stat e but the diversion is

increase d to 0.45 m3/s with off-ch annel

storage, 0.29 m3/s to Roo defontein, inclu de

River EW R

157 51 208 89.70% A/B

Future

Scenario 3


increased to 0.65 m 3/ s a bst raction

(unconstrained), include River EWR

148 51 199 85.80% B

Future

Scenario 4


increased to 1 .0 m3/s (u ncon strained), include

River EW R

140 51 191 82.30% B

Water

re sourceW MA

Quaternary

catchmentPES EIS R EC

vMAR

(MCM)

Reserve (% of

vM AR)

Level of Reserve

Dete rmination

Keurbooms

Estua ryGo uritz K60E/F A/B High A/B 232 92.2 Rapid



xxii

absence of data (i.e. only one hydrographical station located in the lower part of the Bitou

Arm) no recommendations could be made regarding future abstraction from the Bitou

catchment.

If the scenario recommended by the Rapid Reserve Determination study were to be

implemented, it was recommended that the following mitigation measures be investigated

(with full stakeholder participation) and incorporated in the license agreement between

the Bitou Municipality and DWA:

1. Bitou Drift: The drift through the Bitou River should be removed.

2. Northern floodplain of the lower Bitou Estuary: Remove all exotic trees; no further

development; and remove the old gravel road to the south of the R340.

3. Southern floodplain of the lower Bitou Estuary: Remove all exotic plant species;

remove the infilling; and create a buffer zone (~ 10 m wide separating the wetland

from the agricultural activities on the floodplain).

4. Road Bridge across the lower Bitou Estuary: Remove concrete piers of the old road

bridge and establish connection with old Bitou channel.

5. Middle reaches of the Keurbooms Estuary: Remove all alien trees; establish a buffer

adjacent to the estuary and restrict new development.

6. Upper reaches of the Ganse Spruit: Remove exotic vegetation from the stream bed.

7. The Ganse Spruit Wetlands: Install large culverts in the roads to allow the free flow of

surface water through the wetlands; and remove all exotic invasive tree species.

8. Earthen barricades across tidal channels in the Bitou Arm: Remove earthen

barricades to restore connectivity on the supratidal marsh; and maintain freshwater

flow from northern sections into the supratidal marsh south of the R340.

9. Middle reaches of the Bitou Estuary: Remove exotic tree species; allow the artificial

canal to naturally silt up; allow salt marsh to naturally re-colonise the extensive

grasslands; and insert culverts below the road bisecting the floodplain to link up the

old channels.

10. Old Cape Road canal: Increase the width and depth of the canal to facilitate flushing

of the Bitou.

11. Development of an Estuary Management Plan: It is also recommended that an

Estuary Management Plan (EMP) be developed for the Keurbooms Estuary (includes

Bitou Estuary).

PRESSURES/RISKS/THREATS

Pressures currently contributing to the present state of the Keurbooms and Bitou

Estuaries, in terms of water quantity and quality issues are fishing and bait collecting

activities, human disturbance in and around the estuary (wastewater discharge;

recreational activities), structures in the intertidal and supratidal (floodplain) area and

flow reduction from the Keurbooms and Bitou catchments (abstraction and

impoundments/dams.



xxiii

CHAPTER 7 - CLASSIFICATION, ECONOMIC VALUE,

PROTECTION AND REHABILITATION

CLASSIFICATION

The Keurbooms has been ranked as the 18th

most important estuary in South Africa in

terms of biodiversity with an overall importance score of 88 out of a possible 100. An

A/B management class has also been ascribed to the system based on the freshwater

requirements. In order to maintain the system in the A/B class, the Rapid Reserve

Determination study recommends a scenario where abstraction or diversion of freshwater

(to Plettenberg Bay) can be increased to 0.45 m3/s from the present diversion of 0.1 m

3/s.

A botanical rating system that takes functional importance, species richness, plant

community type richness and plant community type rarity into account resulted in the

Keurbooms system being ranked 27th

out of 30 warm-temperate estuaries, with a rating of

235. The top ranked warm-temperate estuary is Knysna with a rating of 360. The

Keurbooms system does not rank in the top 36 estuaries in the country in terms of

botanical importance.

ECONOMIC VALUE

The following economic values have been placed on the Keurbooms Estuary:

Subsistence - ranked 7th

amongst temperate systems with a value of R379 006 per

annum.

Property – ranked 10th

amongst temperate systems in terms of property value related to

estuaries with a value of R399 million.

Tourism – ranked 2nd

amongst temperate systems in terms of tourism value attributed to

estuaries with a value of R400 million per year.

Nursery (protection of juvenile organisms) – ranked 11h amongst temperate systems

with a value of R13.8 million per annum.

Existence – the Keurbooms does not rank amongst the top 40 temperate estuaries.

PROTECTED AREA STRATEGY AND POTENTIAL

PROTECTION OF HABITAT TYPES

Targets for the protection of estuarine habitat types (as a percentage of the total estuarine

habitat measured in hectares) found in the Keurbooms are supratidal salt marsh (30%);

intertidal salt marsh (40%); reeds and sedges (20%); sand/mud banks (40%); submerged

macrophytes (40%); and estuary channel (30%). The overall percentage of all habitat

types combined that should be protected is 30% of the total available 25 095 hectares.



xxiv

PROTECTION OF FISH AND BIRD SPECIES

Targets for the protection of fish and bird species (as a percentage of the total population)

have been set at 50% of the population of red data (threatened) species; 40% of the

population of exploited species; and 30% of the population of all other species. Amongst

the bird species it is only the African black oystercatcher that is a listed threatened

species with the remaining assemblage falling under the 30% protection target. Amongst

the fish it is only the Knysna seahorse that is endangered, and all fish assumed to feature

prominently in fishermen’s catches, such as dusky kob, spotted grunter, white steenbras

and bait species such as mullet are targeted for 40% protection of the population.

TYPE OR LEVEL OF PROTECTION

In order for conservation targets and goals to be achieved, 80% of temperate estuaries

needed some form of partial protection rather than a few with total protection. The partial

protection of 80% of estuaries is deemed desirable from a management perspective, in

that it would facilitate the introduction of an almost universal sanctuary zone in each

estuary, which is marked by standard markers, which in turn would facilitate public

awareness about the estuarine protection system.

Initial guidelines for the conservation of estuarine biodiversity required that estuaries be

assigned to one of three categories, namely Estuary Protected Areas (EPAs), Estuary

Conservation Areas (ECAs), or Estuary Management Areas (EMAs). However, due to

complications that arise between fully and partially protected systems with respect to

national legislation and the subsequent administration of EPAs and ECAs it has been

recommended that the above categories be scrapped and that zonation be used instead as

a general strategy in the management of estuaries. Essentially this means that the

estuaries selected to form part of an overall protection network should contain a

sanctuary zone and should receive sufficient protection and sufficient quantity and

quality of freshwater inflows to be maintained in an appropriate state of health.

The zonation strategy means that individual estuaries may contain a fully protected

(sanctuary) area, which would include terrestrial margins, and a conservation area that

would be zoned according to the vision and objectives/requirements for that estuary.

Sanctuary areas would fulfill the same function as an EPA and as such would have to be

set up and managed by an organ of the state. Conservation areas may be managed by a

wide variety of styles within a co-management setup where the community and an

estuary management forum are the main role players.

THE KEURBOOMS IN PERSPECTIVE

Based on the findings of Turpie and Clark (2007), the following can be said about the

Keurbooms/Bitou estuaries with regards to requirements in terms of protection:

• The Keurbooms is one of the core set of temperate estuaries required to meet the

targets for biodiversity protection of estuarine resources.



xxv

• Targets for the protection of habitat types are as follows; supratidal salt marsh (30%);

intertidal salt marsh (40%); reeds and sedges (20%); sand/mud banks (40%);

submerged macrophytes (40%); and estuary channel (30%).

• The recommended extent of undeveloped margin is 50%.

• The recommended minimum water requirement falls under the A/B management

class.

RESTORATION/REHABILITATION

A workshop attended by estuarine scientists and managers was held to determine which

temperate estuaries should be prioritized for rehabilitation and which issues should be

addressed in each estuary. Thirty-nine estuaries, including the Keurbooms, were given a

HIGH priority status for rehabilitation. According to the consensus opinion at the

workshop the single requirement for rehabilitation on the Keurbooms Estuary is clearing

of alien vegetation. Interestingly there is no mention of restoration of areas that have

undergone inappropriate bank stabilization, but the report pre-dates the 2007 floods that

caused extensive damage and resulted in large areas of the banks in the lower-reaches

being stabilized by property owners. There is also no mention of the rehabilitation of the

Bitou wetlands, which is seen as a priority by this report; this can be accomplished in

cooperation with landowners and NGOs such as Working for Wetlands.

CLIMATE CHANGE

There are several threats associated with climate change that are of particular relevance to

estuaries, their users and the surrounding area. These include decreased rainfall (drought),

increased rainfall and frequency of freshwater floods, increased water temperature

(marine/estuary), sea-level rise and increased frequency and intensity of storm events.

These are all relevant to the Keurbooms/Bitou area as drought can affect farmers and the

availability of the ecological reserve, flooding events can be devastating in the area,

increased temperature affects the survival and distribution of species and sea-level rise

and storm events pose a threat to landowners and infrastructure, either on their own or

when occurring together.

The Western Cape Provincial Spatial Development Framework takes climate change

into account and categorically states that:

“No further urban development shall be permitted on open coast lines that are

vulnerable to erosion, inlets that are susceptible to increased storm activity, river

banks that are liable to flooding, coastal buffer zones and ecological setback lines in

estuaries and below the 1:50 year floodlines (erven) and the 1:100 year floodline

(building platform).”



xxvi

CHAPTER 8 - THE WAY FORWARD: OBJECTIVE II

LOCAL ESTUARY MANAGEMENT FORUM

Objective II involves the process of formulating an Estuary Management Plan (EMP) for

the Keurbooms and Bitou Estuaries. The EMP should be implemented with the help of a

constituted local management institution, which represents all the relevant stakeholders

and their interests. This management institution would take the form of an Estuary

Management Forum (EMF), comprising a chairman, technical working groups for key

result areas (Biodiversity conservation; Exploitation of living resources; Land-use and

infrastructure development; Water quantity and quality; Institutional and management

structures; Tourism; Sustainable livelihoods; and Education and awareness) and the

forum itself consisting of all stakeholders.

The technical working groups should ideally include representatives from the authorities

who have a mandate and executive powers within the specific sector as well as competent

natural or social science specialists acting in an advisory role. It is likely that CapeNature

will be the lead authority.

THE ESTUARY MANAGEMENT PLAN

Key to the formulation of an EMP will be the organization of a stakeholder workshop in

order to develop a vision and objectives for the Keurbooms and Bitou systems based on

the Situation Assessment (this report) and the future needs and desires of the

stakeholders. These outcomes together with the assessment provided by Turpie and Clark

(2007), the Rapid Reserve Determination study and the C.A.P.E. Generic Framework for

EMPs will be used to formulate the EMP.

Essentially the following tasks will be performed for Objective II:

• Assist in setting a Vision and Strategic Objectives for the Keurbooms and Bitou

Estuaries.

• Develop a range of Management Strategies to achieve the Vision and Objectives.

• Prepare an Estuary Zonation Plan (EZP) and Operational Objectives based on the

above.

• Identify Management Action Plans (MAPs) to achieve all strategies and operational

objectives including implementation procedures (includes human and financial

resources).

• Propose an institutional structure (i.e. the EMF) to guide the implementation of the

EMP.

• Develop a monitoring and evaluation programme including a description of a process

for reviewing the management plans.

• Identify research priorities.



xxvii

ISSUES RAISED BY STAKEHOLDERS

The following issues were identified during stakeholder meetings. These will be

addressed in the EMP and do not appear in any particular order:

• An improved zonation plan is required (includes indication of floodlines, wake-free

and skiing zones).

• Estuary-specific by-laws are urgently required so that issues such as houseboats and

wake-free zones can be enforced. Speeding boats below the N2 bridges are a threat to

safety and interfere with other recreational activities such as fishing. Area above N2

bridge on Keurbooms is covered by Keurbooms Nature Reserve and enforced by

CapeNature Ordinance.

• Wake-free zones need to be indicated as such and NOT as 10 kph.

• Implementation of the Ecological Reserve.

• Alien vegetation clearing, both in the catchment and within estuary area.

• Contaminated freshwater runoff from farmlands and commercial forestry plantations.

• Conservation of wetlands (includes saltmarsh) associated with both systems.

• Compliance monitoring needs to be improved.

• Water licensing and use (abstraction) needs to conform to Reserve Determination

recommendations.

• Sewage pump stations on eastern side of Keurbooms cannot cope with peak season

loads.

• Incorporation of 1:100-year floodline in zonation to restrict irresponsible

development.

• Consider making the Bird Sanctuary a no-go area to reduce disturbance.

• General monitoring of water quality, particularly at sites where sewage may enter the

system (e.g. Rietvlei and Gansvlei areas).

• A Municipal environmental officer is required.

• More stringent control over bait collecting activities (includes illegal selling).

• The availability of recreational fishing permits over the weekend was viewed as

problematic and could impact on tourism.

• Threatened species such as the Knysna seahorse and pansy shell and their preferred

habitat need to be protected (adjacent to the Keurbooms Lagoon Caravan Park for

pansy shells and in the region of the confluence for the Knysna seahorse).

• Time taken to obtain authorization to carry out rehabilitation after floods is excessive

and leads to illegal activities; process needs to be streamlined and a standardized

approach adopted to cover instances of repeated damage after each flood event.

• No fishing competitions.

• Education and awareness programmes need to be initiated (regulations, importance of

estuaries etc.). Adopt an approach of education before issuing of fines.

• Abandoned hake long-line vessels on the Keurbooms need to be removed (safety and

possible pollution source).

• Impact of a possible desalination plant.

• Reinstate financial assistance from the Municipality to help with CapeNature’s

management actions outside of the Nature Reserve.



xxviii

• Additional field rangers (two) required so CapeNature can operate effectively.

• Investigate feasibility of making funds from boat licenses available for management

actions.

• Compliance of CapeNature personnel with skippers’ license requirements.

• Feasibility and impact of dredging to deal with excessive sediment loads.

• The proposed N2 bypass route through the lower reaches (SANRAL) needs to be

considered.

• Impact of a major dam in the Keurbooms and/or Bitou catchment.

• All management interventions that affect landowners need to be a part of a public

participation process, i.e. cooperative and not prescriptive.

• Feasibility of off-stream storage of excess flood waters to offset shortages during

times of drought.

• Clearing of debris (from alien clearing) in the catchment to reduce damages from

floods.

• Feasibility of landowners undertaking alien clearing (using own labour) as long as

funding is made available.

• Clearly indicate which government departments are responsible (mandated) for which

management interventions.

• Need to highlight the Keurbooms as a unique tourist attraction (e.g. same as

Robberg).

• Investigate additional activities that can add to attraction of the Keurbooms as a

tourist destination (e.g. hiking trails and sporting events).

• Bank erosion, from clearing of aliens, is an issue in the upper Keurbooms catchment.

• Capacity of Bitou sewerage treatment works to cope with increased development.

• Government involvement is required in the long term to ensure implementation.

In addition to the above, the mitigation measures recommended by the Reserve

Determination study will be included in the EMP.



xxix

LIST OF TABLES, FIGURES AND PLATES

TABLES

Table 4.1 Summary of International obligations and their relevance to estuarine

management.

Table 4.2 Summary of national legislation and its relevance to estuarine management

(from Taljaard 2007).

Table 4.3 Summary of national policies (white papers) relevant to estuarine management


Table 4.4 Themes and Strategic Components of C.A.P.E. (after DMP 2004).

Table 6.1 Details of the quaternary catchments of the Keurbooms catchment K60.

Table 6.2 Present and future water sources of the Bitou Municipality.

Table 6.3 Monthly flow volumes (x 106 m

3) for Newlands K6H019A01 gauging station

for 1997 to present (# indicates incomplete data set).

Table 6.4 MAR values for the Keurbooms and Bitou rivers (after Bornman and Adams

2005).

Table 6.5 Generic ecological categories for EcoStatus components (DWAF 2008;

modified from Kleynhans et al. 2005).

Table 6.6 Generic ecological categories for EcoStatus components (Kleynhans et al.

2005).

Table 6.7 A summary of the mean annual runoffs (MAR) of the various Simulated

Monthly Runoff Scenarios used for this Rapid level determination with the PES under

each scenario.

Table 7.1 Target percentages for the protection of selected estuarine fish and bird species

(after Turpie and Clark 2007).

FIGURES

Figure 2.1 The Keurbooms and Bitou Estuaries and the Keurbooms lagoon or basin

(from CSIR 2007).

Figure 2.2 Structures associated with the Bitou and Keurbooms Estuaries and the 100

and 1 000 m coastal protection buffer zones.



xxx

Figure 3.1 Vegetation and habitat map of the Bitou Estuary and the lower and middle

reaches of the Keurbooms Lagoon and Estuary (Bornman and Adams 2007).

Figure 4.1 Conservation status of the Bitou Municipal Area.

Figure 4.2 Bio-regional Framework of the Bitou Municipal Area.

Figure 6.1 Locality map indicating the various quaternary catchments associated with the

Keurbooms / Bitou rivers (from Haigh and Bekker 2005).

Figure 6.2 Mean monthly precipitation over 20 years from 1984 to May 2004.

Figure 6.3 The middle and lower reaches of the Keurbooms Estuary (after Bornman and

Adams 2005).

Figure 6.4 Extent of the Keurbooms and Bitou Estuaries as used for the Reserve

determination study – 5 m contour line not shown (Bitou Municipality 2008).

PLATES

Plate 2.1 The Bitou Estuary showing the remnants of the old N2 bridge (top left), the

floodplain above the bridge on the north bank (top right) and the Rietvlei wetland above

the bridge to the south (middle left); the Gansvlei wetland in the region of the confluence

(middle right); and the Keurbooms Estuary showing the steep gorges in the upper reaches

(bottom left) and the shallow intertidal regions adjacent to the Anath Peninsula (bottom

right).

Plate 2.2 The road bridge and causeway over the Bitou Estuary near Wittedrift (left) and

the extensive sandbanks in the vicinity of Stanley’s Island (left).

Plate 2.3 The upper reaches of the Keurbooms Estuary at Whisky Creek with the

demarcation barrels preventing boats from venturing further upstream (top left and right);

one of the few jetties on the Keurbooms Estuary (middle left); and boats moored on poles

driven into the sediment (middle right) or on makeshift anchors (bottom).

Plate 2.4 Flood damage on the Keurbooms in the middle reaches at Forever Resorts (top

left), the lower reaches (top right) and the upper reaches at one of the CapeNature picnic

sites (bottom).

Plate 2.5 Attempts at bank stabilization in the lower reaches of the Keurbooms Estuary

have met with varying degrees of success.

Plate 3.1 Clearing and stand of Alien Poplar (Populus sp.) trees alongside the Bitou

River just above the upper reaches of the estuary.



xxxi

LIST OF ACRONYMS

BAS Best Attainable State

CAP Coastal Action Plan

C.A.P.E. Cape Action for People and the Environment

CapeNature Western Cape Nature Conservation Board

CARA Conservation of Agricultural resources Act (Act 43 of 1983)

CD: RDM Chief Directorate: Resource Directed Measures

CFR Cape Floristic Region

CMP Coastal Management Programme

CPUE Catch-per-unit-effort

CSIR Council for Scientific and Industrial Research

CWAC Coordinated Waterbird Counts

DAFF Department of Agriculture, Forestry and Fisheries

DEADP Western Cape Department Environmental Affairs and Development Planning

DEA Department of Environmental Affairs

DIN Dissolved Inorganic Nitrogen

DO Dissolved Oxygen

DRP Dissolved Reactive Phosphate

DRS Dissolved Reactive Silicate

DWA Department of Water Affairs

DWAF Department of Water Affairs and Forestry

DWEA Department of Water and Environmental Affairs

ECA Estuary Conservation Areas

EFA Enviro-Fish Africa (Pty) Ltd.

EHI Estuarine Health Index

EIA Environmental Impact Assessment

EIS Ecological Importance and Sensitivity

EMA Estuary Management Areas

EMC Ecological Management Class

EMF Estuary Management Forum

EMP Estuary Management Plan

EPA Estuary Protected Area

EWR Ecological Water Requirements

EZP Estuary Zonation Plan

GRI Garden Route Initiative

ICMA Integrated Coastal Management Act (Act 24 of 2008)

IDP Integrated Development Plan

IFR Instream Flow Requirements

IHI Index of Habitat Integrity

IUCN International Union for Conservation of Nature

MAP Management Action Plan

MaP Mean Annual Precipitation

MAR Mean Annual Runoff

MCM Branch: Marine and Coastal Management (DEA)

MCM/annum Million cubic metres per annum

MLRA Marine Living Resources Act (Act 18 of 1998)

MSL Mean Sea Level

NEMA National Environmental Management Act (Act 107 of 1998)



xxxii

NGO Non-Governmental Organization

NMMU Nelson Mandela Metropolitan University

NWA National Water Act (Act 36 of 1998)

PES Present Ecological State

PGDS Provincial Growth and Development Strategy

PSDF Provincial Spatial Development Framework

RDM Resource Directed Measures

REC Recommended Ecological Category

REI River Estuarine Interface

RHP River Health Programme

RQO Resource Quality Objectives

SDF Spatial Development Framework

SDP Spatial Development Plan

STEP Subtropical Thicket Ecosystem Plan

STW Sewage Treatment Works

WMA Water Management Area

WULA Water Use License Application



1

CHAPTER 1 - INTRODUCTION

1.1 INTRODUCTION

Estuarine ecosystems are not isolated systems. They form an interface between marine and

freshwater systems and are part of regional, national and global ecosystems either directly via

water flows or indirectly through the movement of fauna. In addition to the biota that these

estuaries support, they provide a range of goods and services (uses) to the inhabitants of the

various regions. Disturbances in one estuary can influence a wide variety of habitats and

organisms in the broader freshwater or marine ecosystem. Thus, the interaction between the

systems and users creates a delicate balance, the sustainability of which needs to be addressed

by some form of management plan.

In order to address this balance in a consistent manner in the Cape Floristic Region (CFR),

the Cape Action for People and the Environment (C.A.P.E.) Estuaries Programme has

developed a holistic and inclusive management process representative of all stakeholders.

The programme is governed by a Task Team comprising of officials from C.A.P.E., Cape

Nature, Marine and Coastal Management (MCM), the Department of Water Affairs (DWA),

the Eastern Cape Parks Board (ECPB) and the Council for Scientific and Industrial Research

(CSIR), which heads the technical support group.

The urgent need for Estuary Management Plans (EMPs) became apparent during the

development of the Integrated Coastal Management Act (Act 24 of 2008; ICMA). Estuaries

and the management thereof have not been adequately addressed by past marine, freshwater

and biodiversity conservation Acts. Estuaries and estuary management have been

marginalized due to the fact that they did not fit the ambit of any one government department.

Estuaries and the management thereof now form an integral part of the ICMA, which

identifies the need for the development of EMPs, as these would help to align and coordinate

estuaries management at a local level. According to the ICMA, EMPs need to be developed

in accordance with a National Estuarine Management Protocol. However, until such time as

this protocol is developed, EMPs are formulated along the lines of the C.A.P.E. Generic

Framework for EMPs (van Niekerk and Taljaard 2007).

Enviro-Fish Africa (Pty) Ltd. (EFA) has been contracted by the C.A.P.E. Estuaries

Programme to address the development of an EMP for the Keurbooms and Bitou Estuaries.

This report fulfills the requirements of Objective 1, namely a Situation Assessment.

1.2 TERMS OF REFERENCE

OBJECTIVE 1: SITUATION ASSESSMENT

The consultant is expected to review all existing information in the form of scientific

literature, local research reports and municipal management and planning documents. A map

of the Keurbooms and Bitou Estuaries should be developed identifying different habitats and

potential and existing management zones. The map should identify and record all

developments in at least a 500m zone surrounding the estuary. The possible direct impacts of

these and other local developments should be noted.

The description of the current situation should include information on:



2

• Legal requirements relevant to the specific estuary;

• Requirements stipulated under existing institutional Management Strategies such as

Catchment Management Strategies, IDP, SDF, RAMSAR & National Heritage Site

Strategies and Protected Area & Conservation Plans (e.g. C.A.P.E. Estuaries) relevant

to the study area;

• The Biophysical environment (present ecological health and important physical

processes);

• The Socio-Economic environment (e.g. demographics & economic profile, land-use and

planning provisions, cultural & heritage resources, water supply & demand, waste

management etc.);

• Conservation planning;

• The exploitation of living resources;

• Mariculture activities;

• Resource Directed Measures, e.g. Classification, Reserve and RQOs; and

• Current institutional structures governing estuary issues.

The estuaries should be represented spatially in the form of GIS Maps indicating the

following (some of these are not applicable to the Keurbooms/Bitou, e.g. mariculture and

solid waste dump sites):

• Important biophysical features

• All protected/conservation areas

• Areas earmarked for rehabilitation

• Land-use and planning provisions of surrounding lands

• Infrastructure

• Cultural & heritage sites

• Recreational activities

• Living resource exploitation

• Mariculture activities

• Wastewater discharges

• Stormwater drains

• Solid waste dump sites.

1.3 PROJECT TEAM

Overall responsibility for the project lies with Enviro-Fish Africa (Pty) Ltd. The project and

team will be managed by Dr Tim Andrew of EFA; Dr Aidan Wood from Gleneagles

Environmental Consulting CC is the project coordinator and will also provide specialist input

with regards living resource exploitation and bio-physical & socio-economic aspects; Drs

Patsy Scherman and Brian Colloty from Scherman Colloty & Associates will provide

specialist input with regards the catchment, water use and water requirements; and Mr

Russell Chalmers, a PhD candidate at Rhodes University, will be responsible for all mapping

and GIS work.



3

CHAPTER 2 – PHYSICAL DESCRIPTION

2.1 INTRODUCTION

The Keurbooms and Bitou estuaries are located close to the coastal town of Plettenberg Bay

and both feed into what is known as the Keurbooms lagoon or basin, a 500 m wide stretch of

water (also known as a back-barrier lagoon) separated from the sea by a prominent berm,

prior to it flowing out to sea (Figure 2.1). The confluence of the Bitou and Keurbooms

estuaries is approximately 3.5 km from the mouth. The Bitou River is 23 km long, with its

source at Buffelsnek, and is tidal for 7.2 km from the confluence to the causeway at

Wittedrift. The Keurbooms River is approximately 85 km long (Harrison et al. 2001), with its

source at Spitskop in the Outeniqua Mountains (Duvenage and Morant 1984), and is tidal for

approximately 8.5 km from the confluence to about 1.5 km upstream of Whiskey Creek. The

combined catchment has been estimated at anywhere between 1085 and 1188 km2 (Heydorn

and Tinley 1980; Day 1981; Reddering 1981).

Figure 2.1 The Keurbooms and Bitou Estuaries and the Keurbooms lagoon or basin (from

CSIR 2007).

Major tributaries of the Keurbooms are the Hartbees, Duiwelsgat, Palmiet, Klein, Diep,

Witels, Kwaai, Peters, Bos and Kykoerie Rivers. A few minor streams flow into the lower



4

Bitou, but the major catchment tributaries are the Kleineiland, Petrus Brand and Rondebos

Rivers (Duvenage and Morant 1984).

Due to the close association between the two estuaries and the fact that they meet at the

confluence prior to the permanently open mouth, the two systems and the lagoon are often

collectively referred to as the Keurbooms. In this report, when using the term Keurbooms it

will be referring to both systems; when one or the other is specifically being referred to the

term “Estuary” will be used after the name. The Keurbooms is a warm-temperate estuary,

regarded by Whitfield (2000) as being in good condition, although he highlights a major

threat as being the construction of a large dam in the catchment of the Keurbooms River

(most likely on the major tributary - the Palmiet River). Eden to Addo (2010) also refer to the

possibility of a storage dam in the upper Bitou catchment. Harrison et al. (2000) class the

Keurbooms as a warm-temperate, permanently open, medium-large, Type F barred system

(supratidal barrier), whose ichthyofauna, water quality and aesthetics are rated as good, good

and moderate respectively. The upper reaches of the Keurbooms Estuary above the N2 bridge

are spectacular and the moderate aesthetics rating is thought to be due to the extensive urban

development on the middle to lower reaches and lagoon area.

The Bitou Estuary above the N2 is characterized by an extensive floodplain and wetland

complex, while the Keurbooms Estuary above the N2 has no floodplain and is characterized

by steep gorges (Plate 2.1). Extensive intertidal areas, dominated by sandbanks, mudbanks,

saltmarsh and freshwater creeks, characterize both estuaries below the N2 and the lagoon

area. The tidal flow of the Bitou Estuary is restricted by the remnants of the old N2 bridge

(located upstream of the existing bridge) that was washed away in the 1940 floods.

There are two statutory conservation areas, both provincial nature reserves administered by

CapeNature, namely the Keurbooms River Nature Reserve (905 hectares) and the Keurbooms

River Seagull Breeding Colony (39 hectares). Neither of these reserves incorporates any of

the estuary water body, but a substantial portion falls within the defined estuarine area. In

addition to this, there are significant areas of private land that are managed for conservation

purposes (private nature reserves, Middle Keurbooms Conservancy) and the Eden to Addo

Corridor Initiative is looking to protect plant and animal habitats through establishing

biodiversity corridors on privately owned land between formally protected areas.

Analysis of data collected during a survey between 1994 and 1996 showed that land use in

the Keurbooms catchment comprised approximately 15% commercial agriculture

(commercial forestry, improved grasslands, temporary commercial irrigated agriculture such

as orchards, and temporary commercial dryland agriculture) and 85% natural shrubland,

bushland and forest. Very little (<1%) is degraded or developed (includes Plettenberg Bay

area; Harrison et al. 2001). The upper Bitou catchment comprises mostly State owned

indigenous forests; with the rest of the catchment comprising privately owned land (farms,

conservancies, eco-tourism, guest houses and two quarries) with indigenous forest and

cultivated lands (Duvenage and Morant 1984). Between Uplands, Hillview and Wittedrift, a

variety of farming activities take place, including wheat, dairy, vegetables, small amounts of

stock and mixed activities. The lower Bitou catchment comprises mostly farmland, urban

settlements and a sewage treatment works at the head of the Gansevalei.

Aspects dealing with rainfall, runoff, freshwater inflow, flood regimes and the reserve

determination study will be dealt with in Chapter 6, which describes water quantity and

quality issues.



5

Plate 2.1 The Bitou Estuary showing the remnants of the old N2 bridge (top left), the

floodplain above the bridge on the north bank (top right) and the Rietvlei wetland above the

bridge to the south (middle left); the Gansvlei wetland in the region of the confluence (middle

right); and the Keurbooms Estuary showing the steep gorges in the upper reaches (bottom

left) and the shallow intertidal regions adjacent to the Anath Peninsula (bottom right).



6

2.2 THE EXTENT OF THE ESTUARINE AREA

The C.A.P.E. Estuaries Programme considers the National Water Act (Act 36 of 1998;

NWA) definition of an estuary as the most appropriate. It reads as follows; “a partially or

fully enclosed water body that is open to the sea permanently or periodically, and within

which the seawater can be diluted, to an extent that is measurable, with freshwater

drained from land.” For the purposes of determining the Resource Directed Measures

(RDM), the Department of Water Affairs (DWA) defines the geographical boundaries of an

estuary as follows; “the seaward boundary is the estuary mouth and the upper boundary

the full extent of tidal influence or saline intrusion, whichever is furthest upstream, with

the five meter above Mean Sea Level (MSL) contour defined as the lateral boundaries.”

The extent of the estuary area for the Keurbooms and Bitou Estuaries is shown in Figure 2.2.

The Keurbooms Estuary extends approximately 1.5 km upstream from Whiskey Creek and

the Bitou Estuary extends as far as the causeway over the Wittedrift road. These are the

generally accepted limits, but the exact upper limit of each estuary at any one time will vary

depending on tidal flows in relation to the volume of freshwater entering from upstream. The

seaward extent of the Keurbooms Lagoon is located at the mouth, which varies according to

the location where floods breach the barrier and the subsequent rate of migration in a SW

direction. When the mouth is located east of its existing position, a blind arm of the lagoon

exists in the SW corner; this too is a part of the estuary area.

With regards the lateral terrestrial boundaries, there are several options commonly used to

define the area, namely:

• Floodlines – either the 1:50 or 1:100 year floodlines. These provide a good indication of

the historical extent of floods and therefore areas that pose a risk for developments and

infrastructure. However, these floodlines are not available for many estuaries and also do

not indicate the possible extent of future events that could be more severe due to the

effects of climate change.

• 5 m contour – this may be useful in the context of the projected sea level rise and increase

in the severity of floods and storm events due to climate change. In the context of local

EMPs, the five-meter contour line has its limitations, as the area can either prove to be

extensive for practical implementation, or non-existent where vertical cliffs define the

channel. The 5 m contour line is currently unavailable for the Keurbooms/Bitou systems.

• Coastal protection zone (Figure 2.2) – this zone is defined as a 100 or 1 000 m buffer

zone measured inland from the high water mark and also makes provision for any land

located within the 1:50 year floodline (this may extend beyond the 100 or 1 000 m limit

in certain areas). Essentially, the 100 m zone is defined for areas zoned as urban and the 1

000 m zone is defined for rural (agricultural) areas. It must be made clear that these zones

are designed to restrict certain activities that may interfere with the estuary and its

sensitive riparian areas, but it does NOT mean that no activities may take place. Activities

that should be restricted, or at least assessed prior to authorization are those listed in the

NWA that require a license (e.g. water use), the EIA Regulations (see below) and those

affecting sustainable development and sensitive ecosystems as defined in the principles of

Chapter 1 (Section 2) of the NEMA. These zones do NOT indicate that landowners may

not operate within their boundary, i.e. they do not lose this land, but they must adhere to

sound environmental principles when conducting any activities. For example, all existing

sustainable farming practices that currently take place within the boundaries of existing



7

legislation are not affected, and all new ventures only need to conform to sound

environmental principles in order to get authorization to proceed.

• EIA regulations – although not used to specifically define the estuary area, the 100 m

buffer zone also provides an indication of the area in which listed activities are regulated

relative to the high water mark in accordance with the EIA Regulations.

2.3 PHYSICAL STRUCTURES

The road bridge over the Bitou Estuary at Wittedrift and the old causeway immediately

downstream act as obstructions to water flow and essentially form the upper limit of tidal

exchange in the estuary (Plate 2.2). The existing N2 bridge and embankment obstructs more

than 45% of the river width of the Bitou Estuary (Duvenage and Morant 1984). Floods

washed the older bridge away in 1940 and the remaining concrete piers restrict flow in the

northern channel of the Bitou Estuary. Flow was further restricted by the embankment of the

N2, which completely closed off the main channel and forced water to flow through a

secondary channel. A low causeway (no longer in use) is present across the Bitou Estuary

approximately 1.5 km upstream of the N2 Bridge. This causes some constriction to tidal

flows especially at low tides. The N2 bridge over the Keurbooms Estuary does not appear to

affect the orientation of the channel, but may contribute to increased sediment deposition

immediately downstream in the vicinity of Stanley’s Island (Plate 2.2).

Plate 2.2 The road bridge and causeway over the Bitou Estuary near Wittedrift (left) and the

extensive sandbanks in the vicinity of Stanley’s Island (right).

There are three picnic sites, administered by CapeNature, one on the eastern bank and two on

the western bank of the Keurbooms Estuary above the N2 bridge. A rope and three barrels are

strung across the estuary above Whisky Creek warning boats not to proceed further upstream

(Figure 2.2 and Plate 2.3).

There is one slipway above the N2 bridge on the Keurbooms Estuary at Forever Resorts and

seven below the N2 bridge including one on the beach/sandbank at the Keurbooms Lagoon

Caravan Park (Figure 2.2). There are no slipways upstream of the N2 bridge on the Bitou

Estuary and no jetties upstream of the N2 on either the Bitou or Keurbooms Estuaries. There

are two jetties and one boathouse/jetty on the western side of the Bitou channel below the N2

and a slipway on the eastern side. A single long jetty extends from Stanley’s Island towards

the N2 and a further 4 jetties exist on the eastern side of the eastern Keurbooms channel



8

below the N2. A small-boat harbour, comprising mooring facilities for over 100 boats and a

slipway are located on the western side below the N2 at the Plettenberg Bay Angling Club.

Although the number of jetties on either system is low, many boats are moored on the east

bank of the Keurbooms Estuary below the N2, on the west bank at Forever Resorts above the

N2 and close to the mouth of the Keurbooms Lagoon (Plate 2.3). These are either tied to

wooden poles secured along the bank or anchored on short lines attached to makeshift

anchors.

2.4 PHYSICAL PROPERTIES

2.4.1 DEPTH

The lower reaches of the Keurbooms Estuary is approximately 3 m below mean sea level

(MSL) and becomes shallower towards the middle reaches (0.9 m below MSL; Huizinga and

Slinger 1999) where the channel to the west of Stanley Island is considerably shallower than

the eastern channel. Upstream of the N2 bridge, average depth is considerably greater with

some sections measuring in excess of 20 m below MSL. The estuary becomes very shallow at

and above Whisky Creek. The depth of the Bitou Estuary varies between 2.7 m below and 0.7

m above MSL, with the deeper sections being located upstream of the N2 bridge. Five

surveys of the mouth of the estuary (Keurbooms lagoon) indicated that the depth varied

generally between 1 and 2 m below MSL (Huizinga and Slinger 1999).

Tidal variation (amplitude) inside the mouth is 1.35 m and decreases to 0.95 m at the N2

bridge (Huizinga and Slinger 1999). The tidal variation in the Bitou Estuary is reduced from

1.35 m at the mouth to 0.85 m at the N2 bridge and 0.38 m at the Wittedrift Bridge. Although

tidal variation occurs throughout the estuarine basin on the spring tide, active tidal exchange

in which the entire water column is flushed occurs primarily in the lower reaches below the

N2 bridges (Huizinga and Slinger 1999).

There is no record of mouth closure occurring at the Keurbooms Estuary, but the mouth

sometimes becomes very shallow. It is also a matter of concern that the estuary becomes very

shallow at places between the mouth and the N2 bridges, which indirectly could contribute to

mouth closure occurring in the future. A major long-term impact of water abstraction from

the Keurbooms and Bitou estuaries can be mouth closure. Enough flow should reach the

estuary to prevent this from happening, which limits the volumes of water that can be

abstracted from the Keurbooms and Bitou rivers. The size and depths of the estuary are such

that closure is unlikely to occur in the near future, but the shallowness of the lower estuary is

a major concern, especially if further reduction in river flow would occur (CSIR 2007).

2.4.2 SEDIMENT PROCESSES AND CHARACTERISTICS

The Keurbooms lagoon lies in the sheltered Plettenberg Bay on the southern Cape coast and

is separated from the sea by a coastal barrier. A mobile tidal inlet through the barrier provides

tidal connections between the lagoon and the sea. The Keurbooms and Bitou Estuaries

occupy two drowned river valleys. The bay of Plettenberg Bay is characterized by a wave

dominated shoreline where very high longshore sediment transport rates are recorded during

southeasterly storms (Reddering and Rust 1994). The surf zone is the main sediment source

of the estuary (Reddering 1999). River floods are important to temporarily scour open inlets

and remove tidal-accumulated sediment from the lower reaches (Reddering 1981; 1999).



9

Plate 2.3 The upper reaches of the Keurbooms Estuary at Whisky Creek with the

demarcation barrels preventing boats from venturing further upstream (top left and right); one

of the few jetties on the Keurbooms Estuary (middle left); and boats moored on poles driven

into the sediment (middle right) or on makeshift anchors (bottom).



10

Figure 2.2 Structures associated with the Bitou and Keurbooms Estuaries and the 100 and 1

000 m coastal protection buffer zones.



11

The tidal prism of the Keurbooms / Bitou estuary is in the order of 1.8 x 106 m

3 (Reddering

1981). The mean spring tidal range in the bay is about 1.6 m (increasing to over 2 m during

equinox spring tides). The neap tidal range is very small in the estuary due to the large

accumulation of sand in the tidal inlet. Due to the constriction of the tidal inlet, the estuary is

flood tide dominated with a tidal range of about 60% of that along the beach (Reddering and

Rust 1994). Annually about 1.5 x 104 m

3 of marine sand enters the back-barrier Keurbooms

lagoon (Reddering 1981). In the Keurbooms estuary the scour by tidal flows removes enough

of the wave deposited sand to maintain the inlet channel and allow restricted tidal exchange.

The main inlet channel consists of an ebb-dominated and a flood dominated sector. The ebb-

dominated channel forms the deepest part of the inlet (3- 5 m below MSL). Since the tide is

ebb-dominated, the flood tide has very little effect on sediment in the ebb channel. The flood

dominated channel (along the northern bank) ranges in depth from 0.5 to 2.5 m below MSL

and flood directed bedforms dominate (Reddering and Rust 1994). The flood tide decelerates

as it enters the back-barrier lagoon and deposits a major fraction of its bedload on the flood

tidal deltas (Figure 2.4). As the inlet migrates southwestwards, the flood deltas accrete

laterally into an elongate sediment body that occupies the entire landward edge of the back-

barrier lagoon to form intertidal sand flats. At present the mouth is located at the extreme

southwest end of the lagoon arm, flush against Lookout Rocks.

The inlet migrates southwestward by erosion of the southern inlet margin and the growth of

the northern margin (Reddering and Rust 1994). The primary reason for the southwesterly

migration of the mouth is the scouring of the southwest spit that occurs on ebb tides as the

flow alters direction to accommodate the 45º angle of the mouth to the coastline (Huizinga

and Slinger 1999). During major events the floodwaters breach the spit at the northeastern

corner (Duvenage and Morant 1984). The effect of small to medium sized floods on the

mouth of the estuary is short-lived, as they do not cause breaching of the sand spit and

alteration in the position of the mouth (Huizinga and Slinger 1999). Several evenly spaced

washover channels are present on the sand barrier and washover sand is an important local

source of marine sand in the estuary (Schumann 2003).

Severe flooding occurs in both systems, with the most recent in 2007 being the most

devastating in living memory. Apart from the major damage to infrastructure located on the

floodplain and scouring of sediment along the course of the estuaries, floods have a major

impact on the mouth in the following ways (CSIR 2007):

• The estuary mouth is deepened and widened by the scouring during flood events.

• The normally complex estuary mouth is temporarily straitened by river floods, but after

the floods the normal channel configuration is re-established by the mouth dynamics and

the long shore transport.

• Floods are playing a major role in the long-term sediment dynamics upstream of the

estuary mouth. Ongoing inland movement of marine sediments takes place during periods

when only minor floods occur, causing a gradual shallowing of the estuary. In the long

term this ongoing sedimentation is counter balanced by flushing of sediments during

major floods. Reduction in occurrence and severity of flooding will therefore probably

result in ongoing sedimentation and shallowing of the estuary. This could eventually lead

to a situation whereby mouth closure might occur.

Sediment in the Keurbooms and Bitou Estuaries consists of fine-grained quartz (sand and

silt), organic material and clay. The Keurbooms River and the lower reaches of the Bitou

River are underlain by Tertiary to Quaternary marine and estuarine terrace gravel and partly



12

calcareous sand (Duvenage and Morant 1984). The more extensive supratidal flats lie near

the clay producing sources. These sources are the outcrop of the Cedarberg Shale in the

southern back-barrier lagoon, and the mud bearing Bitou tributary (Reddering and Rust

1994). The Keurbooms River originates in the Tsitsikamma mountain range that forms part of

the Cape Fold Belt. As a result, sediment from the Keurbooms River consists almost

exclusively of quartz sand (Reddering 1981). The drainage basin of the Bitou River is

underlain by semi-consolidated immature sandstone, conglomerate and shale of Cretaceous

age. The sediment yield from this tributary is small but contains clastic suspension material

(clay content between 5 and 25 %; Reddering 1981).

Sediment in the Bitou Estuary is likely to be more resistant to erosion than the sandy

sediment in the Keurbooms Estuary (Reddering 1999). Suspended mud particles entering the

estuary in freshwater, mixes with the saline water in the Bitou Estuary. The presence of

electrolytes in the water causes the clay particles to flocculate and settle from suspension in

the Bitou Estuary (Reddering 1999). Most of the mud from the Bitou Estuary accumulates on

the intertidal saltmarshes and mudflats and very little fine sediment enters the Keurbooms

Estuary from the Bitou Estuary (Reddering 1999).

Meandering tidal creeks traverse the supratidal flats, and during spring high tide form the

water conduits between the estuary and the supratidal flats. Although mostly inactive, these

creeks have a considerable bank full discharge at spring high tide The gradual up-estuary

variation of hydrodynamics and sedimentary conditions has a profound influence on the

behaviour of burrowing organisms.

2.4.3 TEMPERATURE

There is little evidence of vertical temperature stratification, with surface and bottom

temperatures measuring between 12 and 22.9 ºC (Day 1981; Duvenage and Morant 1984;

James and Harrison 2009). This lower limit is likely to be seen during coastal upwelling

events when cold marine water pushes into the system during the flood tide. The normal

temperature regime, which shows a strong seasonal pattern, is between 20 and 25oC in

summer and 15 and 20oC in winter (CSIR 2007). A horizontal gradient exists, with

temperatures increasing upstream; this gradient is known to reverse when there are strong

freshwater flows from the catchment. On average the Bitou Estuary is warmer than the

Keurbooms Estuary.

2.4.4 SALINITY

Day (1981) and Duvenage and Morant (1984) report on salinities ranging from 13 to 34 ppt,

with highest salinities in the mouth region. James and Harrision (2009) recorded surface

salinity between 35 and 15.3 ppt, which was slightly lower on average than values for bottom

waters (35 to 22.6 ppt). This type of stratification is more evident above the N2 bridges and

more pronounced in deeper areas and over the neap tide cycle; salinity decreases as one

moves upstream. On average, the Bitou Estuary is more saline than the Keurbooms Estuary,

perhaps because of a combination of the smaller catchment and thus lower volume of

freshwater inflow and longer residence periods due to obstructions to natural flow (see

Section 3.1.2 on emergent macrophytes for contradictory evidence and explanation). Values

upstream of the N2 bridge in the Keurbooms Estuary are generally <15 ppt on the ebb tide,

but this will vary depending on the volume of freshwater inflows. Salinity levels will

generally decrease over winter due to increased freshwater runoff. Tidal exchange occurs



13

throughout the systems, but the entire water column is only flushed each spring tidal cycle

below the N2 bridges (CSIR 2007).

The location and extent of the River-Estuarine Interface (REI), defined by brackish waters of

<10 ppt, will vary depending on the volume of freshwater inflows. Based on simulations

(Bitou Municipality 2008), the REI in the Keurbooms Estuary may be located above the

Whisky Creek area when mean monthly flows are < 0.5 m3/s, 10 km from the mouth (0.5 –

1.0 m3/s), 4km from the mouth around Stanley’s Island (1.0 – 10 m

3/s) and right as far as the

mouth region when flows exceed 10 m3/s. In the Bitou Estuary, the REI will be located above

the causeway at flows < 0.5 m3/s, above the top third of the arm (0.5 – 1.0 m

3/s), above the

top two-thirds (1.0 – 10 m3/s) and as far as the mouth region when flows exceed 10 m

3/s

1.

2.4.5 pH

The pH in the systems ranges from 6 to 8.6 with values decreasing upstream in the

Keurbooms Estuary in lower salinities but showing an increase upstream in the Bitou Estuary

(CSIR 2007; James and Harrison 2009), possibly due to photosynthetic activity of extensive

Zostera beds. Riverine water in both systems is slightly acidic due to the leaching of humic

acid (Duvenage and Morant 1984).

2.4.6 DISSOLVED OXYGEN

Dissolved oxygen (DO) values in both estuaries may vary between 0 and 11.8 mg/l

(Duvenage and Morant 1984; Grange 1999), with the lowest values being associated with the

deeper sections. These low concentrations may persist in times of prolonged reduced

freshwater flow, as inflow is responsible for flushing these deeper sections. James and

Harrison (2009) report that DO in surface waters (4.5 to 7.3 mg/l) was generally higher than

in bottom waters (3.0 – 7.4 mg/l), with the Keurbooms Estuary exhibiting a decrease in

values upstream where deeper areas are prone to hypoxia. The reverse was evident in the

Bitou Estuary, once again most probably due to the extensive plant growth.

2.4.7 TURBIDITY

Turbidity is very low, with Secchi disc readings averaging between 1.4 and 1.7 m and only

reduced to < 1 m at times of flooding, reflecting systems that have a dominant marine

influence relative to freshwater inputs.

2.4.8 NUTRIENTS

Keurbooms River Nitrate & Nitrite: 0 – 0.48 mg.l-1

. Ammonia: 0 – 0.71 mg.l-1

(Duvenage

and Morant 1984). Keurbooms Estuary Nitrate: 3.5 – 4.5 mg.l-1

. Inorganic orthophosphate:

River: 0 – 0.16 mg.l-1

; Estuary: 0 – 0.9 mg.l-1

. High nutrient levels could be attributed to the

release of sewage into the Bitou Estuary through the Gansvlei wetland system (Duvenage and

Morant 1984). Snow (2005, unpublished data) recorded the following nutrient levels in the

Keurbooms Estuary during a minor flood in 2002: Total Organic Nitrogen ranged from 23.17

µM in the upper reaches to 3.58 µM in the lower reaches; PO4 ranged from 1.96 µM in the

upper reaches to 2.55 at the confluence with the Bitou Estuary; No detectable concentrations

1 Distances from the mouth are indicated at ebb tide.



14

of NH4 was found in the estuary; Silicate ranged from 35.02 in the upper reaches to 81.3 at

the confluence of the Bitou.

The following extract is from the Physical Dynamics Specialist Study for the Rapid Reserve

Determination (CSIR 2007):

Except for measurements taken during March 1987 (in particular those collected from the

‘blind arm’, a then extensive area situated towards the mouth), dissolved inorganic nitrogen

(DIN) concentrations in the Keurbooms Estuary is considered to be relatively low – below

200 µg/ℓ, representative of concentrations measured in the inflowing river and seawater

(NOTE: Total DIN data is not provided for March 1987 as Total ammonia was not recorded

at the time. The above observation is based on the nitrate plus nitrite concentrations). Much

of the catchment consists of Table Mountain Sandstone resulting in relatively little nutrient

enrichment of the river water, while the inorganic nutrient concentrations typically measured

in marine waters off the south coast of South Africa are also generally low. There are also no

major anthropogenic sources of nutrients in the catchment, comprising largely undisturbed

rural areas and limited agriculture development and no large urban or industrial areas.

The high inorganic nitrogen concentrations recorded near the mouth (salinities > 25 ppt)

during March 1987 can only be explained as significant remineralisation/nitrification

occurring within the estuary as Nitrate/Nitrite concentrations in both the sea and river inflow

were much lower. During March 1987 the shallow, ‘blind arm’ comprised a much larger area

than at present and was covered in dense submerged macrophyte beds, providing organic

matter and longer residence time of water for remineralisation/nitrification to show

significant effect. A possible explanation for this phenomenon not being observed in later

surveys is that since 1987 the mouth of the estuary has been migrating towards the west,

significantly reducing the size of the blind arm, thus affecting its potential to contribute to the

inorganic nitrogen budget of the estuary through remineralisation/nitrification.

Although DIN concentrations are relatively low in the Keurbooms Estuary, it does not seem

to become depleted even during periods of lower river inflow, suggesting that the estuary is

fairly well flushed – both through freshwater inflow and tidal exchange - except in the few

deeper pools situated upstream of the N2 in the Keurbooms. Therefore, although DIN inputs

from the river and sea to the estuary may be low, stocks are continuously replenished through

proper flushing – emphasizing the importance of freshwater base flows and maintaining an

open mouth.

Dissolved reactive phosphate (DRP) concentrations in the Keurbooms Estuary are low –

below 50 µg/ℓ. Results showed no specific trend other than reflecting the low concentrations

of the source waters (river: salinity = 0 and sea: salinity = 35).

As for DIN, although DRP concentrations in the Keurbooms Estuary are relatively low,

concentrations do not become depleted. This also supports the suggestion that the Keurbooms

Estuary is still sufficiently flushed - through freshwater base flows and tidal exchange

through the open mouth – to continuously replenish nutrient supplies to the estuary, albeit

low.

As expected the river is a significant source of dissolved reactive silicate (DRS) to the estuary

as reflected in the DRS concentrations increasing with a decrease in salinity (depending upon

catchment characteristics, high DRS concentrations often occur in terrestrial [fluvial] run-off



15

- Eagle and Bartlett 1984). Based on the data collected in the Keurbooms River by DWAF

(2007), DRS concentrations in river inflow can vary considerably although no particular

trend was apparent. Concentrations in seawater remained low, but fairly constant.

2.4.9 POLLUTION

Sewage

Treated sewage from the Bitou treatment facility (see Figure 2.2) is discharged in the Bitou

estuary via the Gansvlei and Rietvlei wetland systems at the head of Goose Valley, increasing

the flux of nutrients into the system (Bornman and Adams 2005). As the town and water

demand grows, so will the volume of sewage that needs to be discharged. Fortunately most of

the treated sewage is currently used to irrigate existing golf courses and polo fields and it is

expected that the demand for treated sewage will grow. There is, however a risk of untreated

sewerage entering the system either due to failed infrastructure at the treatment works

(particularly during peak holiday periods) or floods scouring through the treatment works.

Industrial


Metals

Samples (water, surface sediment and sediment cores) collected from the Keurbooms and

Bitou Estuaries in July 1978 were analyzed for metals in order to serve as a baseline for

future monitoring surveys (Watling and Watling (1982). Water samples were analyzed for

nine elements (copper, lead, zinc, iron manganese, cobalt, nickel, cadmium and mercury)

while sediment samples were analyzed for 16 elements (same as water, but including sodium,

potassium, calcium, strontium, magnesium, aluminium and chromium).

Concentrations of elements in water samples were considered average for similar

southeastern cape rivers, with the exception of lead and cadmium, which were elevated. No

source could be identified and it is thought they may be of geochemical origin.

Metals in surface sediments were considered average, but on average were slightly elevated

in the Bitou when compared to the Keurbooms, possibly due to mineralisation in the

catchment. Concentrations were elevated in the vicinity of the Plettenberg Bay Angling Club

marina on the Keurbooms, most likely as a result of spills and human activity. The

southwestern arm of the lagoon close to Poortjies and Plettenberg Bay exhibited elevated

levels due to contaminated urban runoff. Metals contained in the surface sediments can be

released or remobilized by flooding or dredging and could potentially alter water chemistry

significantly.

Sediment core samples from the Bitou Estuary support the mineralized catchment hypothesis,

with elevated levels of some metals (leached from the sediment in the catchment) being

detected. Concentrations in the Keurbooms Estuary and the lagoon were considered normal.

Although there are no recent data available on trace metal contamination, similar trends are

expected as those found in 1978 (Watling and Watling 1982). However, the rapid urban

development that has since occurred particularly around the basin area may have elevated the

contamination in this area. There has not been any large urban or industrial development in

either the Bitou or Keurbooms catchments since 1978 that could have resulted in metal

contamination further upstream.



16

Mussel tissue (Perna perna) samples collected near the mouth area in 1978 also did not

reveal significantly elevated trace metal concentration (Watling and Watling 1979). However,

rapid urban development that has since occurred in the Plettenberg Bay area may have

changed the situation to some degree.

2.5 FLOODS

2.5.1 FRESHWATER FLOODS

The Keurbooms and Bitou systems are prone to episodic flooding that has catastrophic

consequences for landowners and infrastructure and also poses a risk to human safety.

Floodwaters cause extensive erosion, particularly in the lower reaches where land has been

cleared to make way for residential developments and resorts. The removal of riparian

vegetation weakens the banks’ stability causing it to be undercut and ultimately collapse into

the estuary. This poses a threat to structures (homes) that are built close to the edge and

which may too collapse into the system. In addition, landowners literally lose their property

as it is washed away. Structures such as bridges (old N2 bridge across the Bitou washed away

in 1940), slipways and jetties are severely damaged or washed away and dwellings located

below the floodline are inundated with water. The effects of these floods have been

exacerbated in recent times by the accumulation of debris in the catchment, mostly from

forestry and alien clearing projects. This debris firstly dams the water as it is washed into the

rivers and blocks the channel and then finally releases it when volumes become excessive.

The resultant wall of water then scours down the systems, its destructive force enhanced by

the debris load.

The greatest damage occurs in the Keurbooms system below the N2 bridge, as this is where

the most development has occurred and where vegetation has been cleared (Plate 2.4).

However, most structures adjacent to the estuary, irrespective of their location along its

course are affected to some extent (e.g. CapeNature picnic sites; Plate 2.4). The Bitou

floodplain suffers less direct structural damage to infrastructure and land, but dwellings are

still prone to flooding. The greatest unknown factor is the timing of floods, and with climate

change affecting global weather patterns, this threat may become more frequent and perhaps

more severe.

2.5.2 MARINE (STORM) FLOODS

Flooding from the seaward side during extreme storm events can also cause widespread

damage to property, infrastructure and the banks of the estuary that have been destabilized by

developments. As is the case with freshwater flooding, these events are unpredictable

(frequency and ferocity) and can occur at any time.

2.5.3 RECOMMENDATIONS

The solution to this problem is complex, as most damage occurs to existing structures that

cannot simply be removed from within the threat area. The following recommendations can

be considered:



17

• No new developments within the risk area – this could be the 1:100 year floodline or

below the 5 m contour; the latter may be more applicable if a precautionary approach is to

be adopted that will account for climate change.

• Planting of vegetation along the estuary banks where it has been cleared for

developments.

• Clearing of debris from the catchment by forestry and those responsible for alien clearing

projects.

• Bank stabilization to repair existing damage and to minimize impacts from future events.

Attempts to stabilize the banks in the lower reaches of the Keurbooms have met with

varying levels of success (Plate 2.5) and the EMP will attempt to establish a protocol for

best practice based on existing technologies and past successes. In addition, the

authorization process needs to be revisited (with DEADP) to account for landowners

needing to carry out repairs (to banks, jetties and slipways) after each event without

having to undertake the EIA process each time.

Plate 2.4 Flood damage on the Keurbooms in the middle reaches at Forever Resorts (top

left), the lower reaches (top right) and the upper reaches at one of the CapeNature picnic sites

(bottom).



18

Plate 2.5 Attempts at bank stabilization in the lower reaches of the Keurbooms Estuary have

met with varying degrees of success.



19

CHAPTER 3 – BIOLOGICAL DESCRIPTION

3.1 FLORA

3.1.1 MICROALGAE

Adams et al. (1999) showed that an increase in freshwater input between August and

November 1992 caused a decrease in mean salinity, an increase in the horizontal gradient and

an increase in nitrate (0.3 – 4.4 µM) and chlorophyll-a concentrations (0 – 13.3 µg l-1).

Although Grange (1999) reported that, based on the appearance of filter paper after water had

been passed through it, phytoplankton is of little if any ecological significance in the estuary,

other studies refute this and indicate that freshwater inflow stimulate microalgal growth and

therefore primary productivity. Adams et al. (1999) also reported on the benthic microalgal

biomass that ranged from 106 – 191 mg.m-2 for intertidal sites and 257 to 640 mg.m-2 for

subtidal sites. Compared to other Cape estuaries these values were moderately high. A recent

comparison of benthic microalgal biomass in permanently open estuaries by Snow in 2005

(NMMU; unpublished data) recorded intertidal biomass in the Keurbooms as 9.53 ± 0.78

µg.g-1. This value was lower than most of the other estuaries sampled and was related to the

sandy nature of the estuary and low sediment organic content compared to the other estuaries

included in the analysis.

3.1.2 MACROALGAE

See Figure 3.1 for a fine-scale vegetation distribution map.

Submerged macrophytes

Duvenage and Morant (1984) stated that Zostera capensis is the dominant submerged

macrophyte in the Keurbooms/Bitou system and occurs in both intertidal and subtidal

habitats. More recently, however, Bornman (2004) showed that Ruppia cirrhosa is in fact the

dominant submerged macrophyte in the Bitou Estuary. Although Ruppia has a wide salinity

tolerance range (0-75 ppt), it does not survive in the lower reaches (lagoon area) since it has

relatively weak stems that break in the presence of strong currents. Very little Z. capensis was

found in the Bitou Estuary above the N2 bridge because of reduced tidal action caused by

physical obstructions. Halophila ovalis has also been recorded in the Keurbooms/Bitou

Estuary (Duvenage and Morant 1984).

Emergent macrophytes

In the Keurbooms Estuary, reeds and sedges are limited to the supratidal marshes and areas of

freshwater inflow. The Bitou Estuary is characterized by dense monospecific stands of

Schoenoplectus scirpoides and Phragmites australis within the channel because of the low

flow and restricted tidal action (Bornman 2004). The presence of these species within the

main channel of the Bitou is indicative of relatively low salinities (0 – 25 ppt). This

contradicts the previous statements (see Section 2.3.4 on salinity) that the Bitou Estuary is, on

average, more saline than the Keurbooms. It could be that low flow and increased

evaporation during summer temporarily increases the salinity in the Bitou, but the presence of

the reeds and sedges indicate a fresher state for prolonged periods. Reeds and sedges can

survive tidal inundation with saline water if their roots and rhizomes are located in brackish

water (salinity < 15 ppt). Adams and Bate (1999) showed this for a site in the Keurbooms

lagoon where interstitial water salinity (15-28 ppt) was lower than surface water salinity (34



20

ppt). There was a decrease in the height of P. australis with an increase in interstitial water

salinity (112 cm vs 275 cm).

Intertidal saltmarsh

The dominant intertidal salt marsh species in the Keurbooms are Spartina maritima,

Sarcocornia perennis and Sarcocornia decumbens (Duvenage and Morant 1984). Salt

marshes are not extensive in the Keurbooms Estuary due to the geomorphology of the system

(limited space). The Bitou Estuary has a wide floodplain connected to the estuary by

numerous tidal creeks. The largest areas of salt marsh occur on these floodplains. The species

recorded by Bornman (2004) are very similar to those reported in Duvenage and Morant

(1984).

Supratidal saltmarsh

The elevated areas of the floodplains are covered with supratidal salt marsh vegetation,

mainly dense cover of Sarcocornia pillansii (Bornman 2004). The largest supratidal salt

marshes are found on the floodplain of the Bitou Estuary. Saline groundwater encourages the

growth of salt marsh vegetation on the supratidal flats (Reddering and Rust 1994; Bornman

2004). Mats of grasses such as brakgras (Sporobolus virginicus) and seaside quick

(Stenotaphrum secundatum) dominate large sections of the disturbed upper marsh in both the

Bitou and Keurbooms estuaries (Bornman 2004). The fringes of the floodplains are occupied

by reeds, rushes and sedges, e.g. Juncus kraussii, Juncus acutus, Schoenoplectus lacustris,

Phragmites australis and Typha capensis (Bornman 2004). These plants frequent less saline

areas and are normally an indication of freshwater inflow.

Terrestrial plants

The terrestrial vegetation in the middle and lower reaches can be grouped into five types,

namely primary dune scrub, secondary dune scrub, hind dune scrub, fynbos and aliens.

Distribution patterns and composite species may be found in Duvenage and Morant (1984).

The upper reaches are characterized by dense indigenous forest interspersed with alien trees.

Alien tree species, most notably Acacia melanoxylon, Acacia saligna and Acacia mearnsii,

are invading the floodplain areas of the Bitou and Keurbooms Estuaries (Bornman 2004).

Alien infestation is also a problem within the entire catchment/riverine area and alien clearing

programmes are active in dealing with this problem (Plate 3.1).

Plate 3.1 Clearing and stand of Alien Poplar (Populus sp.) trees alongside the Bitou River

just above the upper reaches of the estuary.



21

Figure 3.1 Vegetation and habitat map of the Bitou Estuary and the lower and middle reaches

of the Keurbooms Lagoon and Estuary (Bornman and Adams 2007).

3.1.3 THE BITOU FLOODPLAIN/WETLAND COMPLEX

(From Allanson Grange Associates 1997; Eden to Addo 2010).

The Bitou wetlands located between the N2 road/bridge and the Bosfontein River are one of

the last undeveloped floodplains along the Western Cape coast and comprise a series of

typical open freshwater marsh systems (Gansevlei and Rietvlei), supra- and inter-tidal

saltmarsh, river channels (Diep River) and the Bitou Estuary channel itself. Floods are

episodic, usually occurring in spring/early summer and are vital for maintaining ecosystem

functioning in combination with the twice-daily tidal cycles (AGA 1997). According to



22

Haigh (2005), the Bitou wetlands are the most valuable ecological resource of the entire

catchment, and are currently under severe threat of development on its perimeter. The

wetland corridor provides a link between the SANParks Forest Reserve and the Keurbooms

Nature Reserve and potentially allows for the movement of species (and therefore genetic

material) between protected areas.

Floodplain saltmarsh areas are dominated by Sarcocornia perennis while riparian areas

comprise mostly reeds (Phragmites australis) and sedge (Scirpus littoralis). Upstream of the

causeway, the riparian vegetation comprises indigenous milkwoods and some yellowwoods.

The floodplain in the upper reaches also comprises scattered concentrations of rush (Juncus

kraussii). The terrestrial portion of the Bitou Valley comprises fynbos associated species,

Valley Thicket and Knysna Afromontane Forest. Commercial forestry and alien species are

the biggest threats in the catchment. Numerous shallow open pans are scattered on the

floodplain and are considered an important habitat for birds.

Levels of phosphate appear to be low in the wetlands, indicating that the system is not

polluted from contaminated agricultural return flows enriched by phosphate-based fertilizers.

Riverine health is considered to be good based on certain indicator species such as

dragonflies.

The Rietvlei wetland system is a complex of seasonal and permanent vegetation including S.

littoralis, Bulboschoenus maritimus, Typhus sp. and aquatic grasses. Baillon’s crake, which is

a Red Data species, is known to breed here and other rare birds such as the redchested

flufftail, African rail, black crake, purple gallinule and purple heron are common residents.

Areas characterized by temporary pools and short grasses are dominated by small waders,

ducks, spoonbills and ibis.

Large areas of the floodplain are used for grazing cattle, but this is not intensive, and

vegetation cover and riparian cover are maintained so that erosion and bank destabilization

(also from trampling) is not a concern. Cows access the water to drink when it is not too

saline. There are several access roads through the floodplain on private property and although

it is unknown whether these have an adverse affect, it is unlikely as they do not block

drainage channels and still allow free movement of water (Personal Observations and

anecdotal information from landowners).

The Gansvlei/Diep River/Rietvlei system of rivers and wetlands serve to filter and further

purify the treated effluent from the Bitou Sewerage Works located at the head of Gansvalei

(this feeds into the Gansvlei). The maintenance of these wetlands as a buffer is important if

water quality entering the Bitou Estuary is to be maintained at an acceptable level.

The major concern emanating from the AGA (1997) study was if the floodplain area was to

be used more intensively from an agricultural point of view. This does not appear to have

happened, although the impact of additional developments adjacent to the Rietvlei (polo

fields and industrial park) and ineffective culverts (too small or blocked) where roads cross

the system need to be determined.

Although the AGA (1997) report recommended that the portions of land comprising the

wetland floodplain system be transferred to a Trust and established as a conservancy, this

never came to fruition, despite support from a range of landowners. The land on the northern

side is currently still being used for grazing and does not appear to have been severely



23

degraded. Meetings with current landowners revealed that they feel they look after the area

already and do not need a conservancy to facilitate a management function they already

fulfill. A recommendation may be to fence off sensitive areas to prevent damage to

vegetation by grazing and trampling, but this will need to be done in cooperation with the

private landowners. In addition, the Eden to Addo initiative (2010; building on AGA 1997) to

establish the Bitou Corridor linking the SANParks and Keurbooms protected areas needs to

be considered in cooperation with landowners.

3.2 FAUNA

A comprehensive list of faunal species that are found or are likely to be found within and in

association with the Keurbooms and Bitou Estuaries is available in Duvenage and Morant

(1984). These lists will not be reproduced here, but key species will be referred to in the

relevant sections.

Zooplankton

Zooplankton displays high species richness in the Keurbooms Estuary, with 39 species being

recorded and a dry biomass of between 2.9 to 108 mg/m3 (Duvenage and Morant 1984).

Pseudodiaptomus hessei is the dominant copepod and is particularly abundant in lower

salinity waters above the N2 bridge in the Keurbooms. A more recent survey by Grange

(1999) reported low biomass of zooplankton.

Benthic invertebrates

Hard (rocky) substrates are scarce in the Keurbooms / Bitou Estuary and as a result there are

limited fauna present that require these habitats. The largest proportion (42 taxa) of the

invertebrate fauna is either benthic or associated with the aquatic vegetation (Duvenage and

Morant 1984; Zoutendyk and Bickerton 1999). The benthic fauna is well developed from the

lower reaches (lagoon) to the middle reaches, with sandparwn (Callianassa kraussi) in sandy

areas, bloodworm (Arenicola loveni) and pencilbait (Solen capensis) in muddy sand and

mudprawn (Upogebia africana) abundant in sandy mud (Day 1981; Grange 1999). The

bivalve Donax spp. (sand mussel) and the echinoids Echinodiscus bisperforatus (pansy shell)

and Echinocardium sp. also burrow the sand in the area proximal to the mouth (Reddering

and Rust 1994). Solen spp. and Arenicola loveni burrow into the sediment of the intertidal

flats (between neap high tide and subtidal levels) and have a limited distribution upstream of

the Keurbooms/Bitou confluence (Duvenage and Morant 1984; Reddering and Rust 1994).

The distal tidal flats are occupied by the prawns C. kraussi, U. africana and the cracker

shrimp (Alpheus crassimanus). The largest and most closely spaced U. africana population

occurs in the Bitou Estuary, where muddier sediments are present (Duvenage and Morant

1984; Reddering and Rust 1994). Their populations are threatened in the system through the

incursion of marine sand and exploitation for bait. Cracker shrimp burrows in the Zostera

covered intertidal areas where the currents are slower. Macro-invertebrates such as

Nassarius, Natica and Diogenes are common on the mid and distal flat areas while the mud

crab (Scylla serrata) is common amongst saltmarsh vegetation and Zostera beds. An

abundance of crabs, either Sesarme castenata or Cleistostoma edwardsii were observed

amongst the mud and creek vegetation of Gansvlei during a recent fieldtrip (Aidan Wood,

Pers. Obs.). Intertidal macro-benthos standing stock (as carbon) ranged from < 10 gC.m-2 in

sand to 100 gC.m-2 in muddy sediments (Zoutendyk and Bickerton 1999). Mudprawn and

sandprawn together contributed more than 50% (26 tonnes) of the standing stock of benthos

carbon in the Keurbooms Estuary.



24

An important component of the soft sediment community is the pansy shell or sand dollar, an

Indo-Pacific species of the family Astriclypeidae, which lives in the upper 5 cm of sediment.

The species inhabits sandy intertidal and subtidal areas to depths of approximately 20 m. Of

the three main populations of E. bisperforatus in South Africa, two are within Plettenberg

Bay. One of these is located along Keurboomsstrand and in the lagoon in the vicinity of the

mouth near the caravan park. The limited distribution and high souvenir value have resulted

in the species being classified as endangered in South Africa, and protected by the Sea

Fisheries Act (Act 82 of 1973) (Bentley and Cockroft 1994).

Amphibians and reptiles

Fourteen amphibian species are likely to be associated with the Keurbooms and Bitou

systems, but only two of these have actually been recorded, namely Heleophryne regis and

Rana fasciata (Duvenage and Morant 1984).

Twenty-seven snake species are likely to be associated with the Keurbooms and Bitou

systems, but only two of these have actually been recorded, namely Lycodonomorphus

rufulus and Bitis atropos.

Three species of tortoise and one species of terrapin are likely to be associated with the

systems, but none have been recorded in the literature.

Freshwater fish

The Keurbooms redfin (Pseudobarbus cf. tenuis) is an endangered species found in the

Kransbos, Diep and Langbos rivers of the catchment and has been identified as requiring

special conservation attention (CapeNature 2007). It has been assigned a high priority, which

means there are less than three populations left and is under severe risk of extinction. In

addition, the following indigenous species are known to occur (Skelton 1994; Russell 2002);

forest redfin (Pseudobarbus afer), Cape galaxias (Galaxias zebratus), Cape kurper (Sandelia

capensis) and longfin eel (Anguilla mossambica). Alien species include rainbow trout

(Onchorynchus mykiss), brown trout (Salmo trutta) and large-mouth bass (Micropterus

salmoides). Two marine-migrant species, namely Cape moony (Monodactylus falciformis)

and freshwater mullet (Myxus capensis) have been found in the riverine region above the

estuary. Interestingly, G. zebratus is represented by its most eastern distribution in the Bitou

River and is not found in the Keurbooms arm of the system (Skelton 1994).

Marine and estuarine fish

The fish fauna of the Keurbooms and Bitou were sampled by multi-mesh gillnets and seine

nets in November 1994 (James and Harrison 2009). A total of 23 species representing 13

families were caught, with the Mugilidae (5 species), Sparidae (4 species) and Gobiidae (4

species) dominating the catch. The Cape stumpnose (Rhabdosargus holubi) was numerically

dominant (46.4% of total catch and mostly newly recruited juveniles) followed by juvenile

mullet (27.5%). Dusky kob (Argyrosomus japonicus) dominated the catch in terms of

biomass (31.1%) followed by the mullet Liza richardsonii (29.2%). The Knysna seahorse

was not recorded during their survey, but Whitfield (1994) reports that it does occur together

with 28 other species (see below). Both reports also include the longsnout pipefish

Syngnathus temminckii2. Both studies report that the fish fauna is dominated by marine-

migrant species (utilize estuaries but spawn at sea), with a large juvenile component mostly

2 Species name outdated – is now designated Syngnathus acus



25

occurring below the N2 bridges, reflecting the importance of these systems as a nursery area

(typical of permanently open estuaries).

In addition to A. japonicus, both systems are home to other important and over-exploited

linefish species such as white steenbras (Lithognathus lithognathus), spotted grunter

(Pomadasys commersonnii) and leervis (Lichia amia). The baardman (Umbrina canariensis),

a marine species is also found in the system and is caught quite regularly. Historical records

show some interesting distributions with Priacanthus hamrur (crescent-tail bigeye, a mostly

sub-tropical to tropical marine species), Trachinocephalus myops (a lizardfish rarely found in

the area) and Stromateus fiatola (blue butterfish; marine species usually found in deeper

waters).

Knysna seahorse

Knysna seahorse (Hippocampus capensis) is the only fully estuarine species and its

distribution amongst aquatic vegetation, has been confirmed historically in only four SA

estuaries, namely Knysna, Swartvlei, Keurbooms/Bitou and Klein Brak (Bell et al. 2003).

However, recent evidence suggests it no longer occurs in the Klein Brak (Teske et al. 2003;

Lockyear et al. 2006). The species does not appear to show a preference for a specific type of

vegetation and is found in association with Zostera capensis, Caulerpa filiformis, Codium

extricatum, Halophila ovalis and Ruppia cirrhosa (Teske et al. 2007). It does however appear

to prefer areas where vegetation cover exceeds 75% and any conservation efforts should

concentrate in sections of the estuary where vegetation cover is high. A survey by Bell et al.

(2003) failed to locate any in the Keurbooms or Bitou estuaries in 29 (30 x 2 m) transects

(total of 12 man hours underwater). However, surveys (at 41 sites) conducted in March/April

of 2002 and 2003 (Lockyear et al. 2006) revealed a density of 0.28/m2 (total number 102) in

2002 but zero in 2003 (possibly due to being washed out by flood waters). Estimates of total

population size in 2002 were 836 298, with the highest density (6/m2) being recorded at the

Bitou/Keurbooms confluence. It is listed as an Endangered species on the International Union

for Conservation of Nature (IUCN) Red List due to its fragmented distribution, small area of

occupancy, the vulnerability of its habitat and susceptibility to high mortality due to

freshwater flooding (Russell 1994). Analysis of mitochondrial DNA sequences suggest that

although the species originated in the Knysna Estuary as much as 486 000 years ago, the

three extant populations are now thought to be distinct, i.e. they do not mix and can thus be

regarded as separate management units (Teske et al. 2003). However, Lockyear et al. (2006)

do propose a hypothesis that the Knysna population may be the source of new colonists for

the Keurbooms after flood events and that the system is merely a temporary habitat for the

species at times when conditions are favorable. Research is urgently required to determine

whether the Keurbooms population is permanent.

Birds

Acknowledgement

Much of the following information has been gleaned from the Coordinated Waterbird Counts

(CWAC) for the Keurbooms River Estuary (Site Code 34022324) between July 1997 and

July 2009. CWAC data were obtained from the Animal Demography Unit, University of

Cape Town. The owner of the data is Mr Brian Denman.

A total of 64 species, totaling 31 051 individuals have been recorded over the 13 year period.

The kelp gull is by far the most dominant species with 9 183 birds being counted, followed

by the swift (great crested) tern (4 953), grey plover (1932), reed cormorant (1 850), curlew



26

sandpiper (1 586), sacred ibis (1 200) and common whimbrel (1 070). Two pursuit-swimming

piscivores, namely the white-breasted cormorant and the Cape cormorant, which are capable

of feeding on up to 16% of their body weight daily, numbered 588 and 462 respectively. A

total of 503 of the endangered African black oystercatcher were counted. Some species were

only counted once or twice and represented by less than 10 individuals, e.g. black-headed

heron (6), Cape shoveler (2), common moorhen (1), great crested grebe (2) and red-knobbed

coot (1). A full list with total numbers is provided in Appendix 1.

The most birds were counted in January 1997, with 2 072 individuals being recorded,

followed by January 1996 (1 695), February 2002 (1 569), January 2005 (1 519) and July

1996 (1 365). In the last year, a total of 1 133 birds were counted in February 2009 and 821 in

July 2009 (Appendix 1). Counts over summer months always exceed those in winter of the

same year due to the influx of summer migrants. In summer the avifauna is dominated by

migratory waders (41%), gulls (mainly Kelp Gull; 29%) and terns (mainly Swift Terns;

15%). The remaining avifauna includes a variety of wading birds (particularly Sacred Ibis

and Reed Cormorant; 8%), resident waders, cormorants and small numbers of waterfowl. In

winter, numbers are dominated by terns (26%) and gulls (21%) and wading birds

(particularly Reed Cormorant and Sacred Ibis; 15%). Resident waders (13%) and migratory

waders (immature over wintering birds; 9%), cormorants (9%) and waterfowl (6%) make up

most of the remainder. About 12% of migratory waders remain in winter. Cormorants and

waterfowl are about three times more abundant in winter than summer, and resident waders

are twice as abundant. Wading birds, kingfishers and terns occur in roughly equal numbers

in summer and winter, but gulls are fewer in winter (italics referenced from Bitou

Municipality 2008).

A report based on CWAC counts between 1992 and 1997 stated that bird species numbers

and total counts for the Bitou Estuary had been on the decrease and this was attributed to

pollution from effluent, pesticides and fertilizers, damage to habitat by livestock, siltation of

the estuary, reed encroachment and residential development (Taylor et al. 1999). An example

is the significant decrease (and sometimes absence) in the two flamingo species. Bird

numbers in the Keurbooms Estuary are threatened by residential development, boating,

fishing, domestic animals and bank erosion, which all contribute to habitat destruction and

disturbance.

The lower Bitou River includes excellent marsh habitat for rails and other secretive birds, and

redchested flufftail and Baillon's crake may breed in this area. Moorhen counts peak in winter

although recorded numbers are decreasing; winter Dabchick counts are also decreasing. The

area is important for foraging and roosting shorebirds, waterfowl and egrets. The Bitou

wetlands system is considered vital from a bird (breeding and biodiversity) point of view and

is need of protection (Haigh 2005).

The following information has not been sourced from the CWAC data:

The bird sanctuary located at the Keurbooms mouth has the largest breeding colony of kelp

gulls in the region, with approximately 1450 breeding pairs recorded in 2003 (Whittington

2004). In addition, the African black oystercatcher and several tern species are also thought to

breed and roost within the sanctuary.



27

Mammals

Common mammals that may be spotted within the Keurbooms Nature Reserve and in close

association with the estuaries include the bushpig, dassie, caracal, genet, baboon, vervet

monkey, blue duiker, bushbuck, grysbok, leopard, mongoose and the Cape clawless otter.

(http://www.capenature.org.za/reserves.htm?reserve=Keurbooms+River+Nature+Reserve#re

serve_tabs).



28

CHAPTER 4 – LEGISLATION AND PLANNING &

DEVELOPMENT STRATEGIES

The purpose of this section is to review all forms of legislation that may have an impact on

the management of the Keurbooms and Bitou Estuaries. This review incorporates

international agreements and strategies as well as all forms of national, regional and local

legislation as well as municipal planning and development strategies.

4.1 INTERNATIONAL OBLIGATIONS (Table 4.1)

Table 4.1 Summary of International obligations and their relevance to estuarine management.

4.2 NATIONAL LEGISLATION (Table 4.2) AND POLICY (Table 4.3)

International Obligations Short Description

Convention on Wetlands of International

Importance especially as Waterfowl Habitat

(1971) (Ramsar Convention)

The broad aims of this Convention are to stem the loss and to promote wise use of all

wetlands (including estuaries).

Agenda 21 (1992) as reaffirmed at the United

Nations World Summit on Sustainable

Development - Johannesburg Summit (2002)

This is not a legally binding document, but Agenda 21 is an internationally accepted

strategy for sustainable development; the principles of sustainable development are

easily applied to the estuarine scenario.

United Nations Convention on Biological

Diversity (1992)

The objectives of convention include the conservation of biological diversity; the

sustainable use of biological resources; and the fair and equitable sharing of benefits

arising from the use of genetic resources.

United Nations Framework Convention on

Climate Change (1992)

This framework sets an "ultimate objective" of stabilizing greenhouse gas

concentrations in the atmosphere at a level that would prevent dangerous

anthropogenic interference with the climate system. This has particular relevance to

estuaries when considering changes in rainfall, storm severity and flood levels and

frequencies.

Global Programme of Action for the Protection

of the Marine Environment from Land-based

Activities (GPA) (1995)

The GPA is designed to assist states in taking action to prevent, reduce, control or

elimination the degradation of the marine environment (including estuaries), and to

assist in its recovery or rehabilitation from the impacts of land-based activities.



29

Table 4.2 Summary of national legislation and its relevance to estuarine management


National Legislation Lead Agent Short Description

National Environmental

Management: Biodiversity

Act (Act 10 of 2004)

DEA This Act provides for the conservation of biological diversity, regulates the sustainable

use of biological resources and ensures a fair and equitable sharing of the benefits


National Health Act (No.

61 of 2004)

Delegated to Provincial and

Local authorities from

Department of Health

Delegated to Provincial and Local authorities from Department of Health


Management: Protected

Areas Act (Act 57 of

2003)

DEA This Act provides for the protection and conservation of ecologically viable areas

representative of South Africa’s biological diversity and its natural landscapes and

seascapes; for the establishment of a national register of all national, provincial and

local protected areas; for the management of those areas in accordance with

national norms and standards; for intergovernmental co-operation and public

consultation in matters concerning protected areas.

Disaster Management Act

(No. 57 of 2002)

Act is administered by a

Cabinet member designated

by the President

To provide for an integrated and coordinated disaster management policy that

focuses on preventing or reducing the risk of disasters, mitigating the severity of

disasters, emergency preparedness, rapid and effective response to disasters and

post-disaster recovery; the establishment of national, provincial and municipal

disaster management centers; disaster management volunteers; and matters

incidental thereto.

Local Government:

Municipal Systems Act

(Act 32 of 2000)

Department of Provincial and

Local Government

This Act deals with Integrated Development Planning (IDP), which is intended to

encompass and harmonize planning over a range of sectors such as water, transport,

land use and environmental management.

Development Facilitation


Same This Act requires the setting of Land Development Objectives and the principles of

this Act have also been incorporated into the Municipal Systems Act.

Local Government

Transition Second

Amendment Act (Act 97

of 1996)

Same This Act requires that all municipalities, local and district councils, draw up IDPs for

the integrated development and management of their areas of jurisdiction.

Local Government

Municipal Structures Act

(No. 117 of 1998,

amended by Act 33 of

2000)

Same This Act provides for “the establishment of municipalities in accordance with the

requirements relating to categories and types of municipality; to establish criteria for

determining the category of municipality in an area” and other related matters.


Management Act (Act 107

of 1998)

DEA and provincial DEADP This Act provides for the conservation of biological diversity, regulates the sustainable

use of biological resources and to ensures a fair and equitable sharing of the benefits



Management: Integrated

Coastal Management Act

(Act 28 of 2008)

DEA (Marine & Coastal

Management)

This Act aims to establish a system of integrated coastal and estuarine management

in South Africa, including norms, standards and policies, to promote the conservation

of the coastal environment, the ecological sustainable development of the coastal

zone, to define rights and duties in relation to coastal areas, to determine responsible

organs of state in relation to coastal areas and to give effect to South Africa’s

international obligations in relation to coastal matters and to provide for related

matters.

National Veld and Forest

Fire Act (No. 101 of 1998)

DWA Sets out to reform the law on veld and forest and provides for matters relating to fire

protection, and fighting, offences and penalties and enforcement.



30


National Water Act (Act

36 of 1998)

DWA This Act ensures protection of the aquatic ecosystems of water resources, including

estuaries. It requires policies to be in place that provide guidance in developing

resource quality objectives, i.e. specifying aspects such as freshwater inflow, water

quality, habitat integrity, biotic composition and functioning requirements.

National Forests Act (No.

84 of 1998)

DWA This Act recognizes that natural forests and woodlands (including riparian vegetation)

form an important part of the environment, and need to be conserved and developed

according to the principles of sustainable management.

Marine Living Resources


DEA (MCM) This Act deals with the utilization, conservation and management of marine living

resources, the need to protect whole ecosystems, preserve marine biodiversity and

minimize marine pollution as well as to comply with international law and agreements

and to restructure the fishing industry.

Water Services Act (No.

108 of 1997)

DWA Right of access to basic water supply and sanitation; control of water services;

preparation of WSDPs.

The Constitution (Act 108

of 1996)

National Government The Constitution is the supreme law of the land and provides the legal framework for

legislation regulating environmental management in general. The most pertinent

fundamental right in the context of estuarine management is the Environmental Right

which provides that, "Everyone has the right: to an environment that is not harmful to

their health or well-being; and to have the environment protected, for the benefit of

present and future generations through reasonable legislative and other measures

that – prevent pollution and ecological degradation; promote conservation; and

secure ecologically sustainable development and use of natural resources while

promoting justifiable economic and social development.

Local Government

Transition Second

Amendment Act (Act 97

of 1996)


Local Government

This Act also requires that all municipalities, local and district councils, draw up IDPs

for the integrated development and management of their areas of jurisdiction.

Tourism Act (No. 72 of

1993, as amended in

1996 & 2000)

DEA No details.

Development Facilitation



Local Government

This Act requires the setting of Land Development Objectives and the principles of

this Act have also been incorporated into the Municipal Systems Act.

Local Government

Transition Act (No. 209 of

1993)


Local Government

To provide for revised interim measures with a view to promoting the restructuring of

local government, and to provide for the establishment of Provincial Committees for

Local Government in respect of the various provinces.

Environmental

Conservation Act (No. 73

of 1989)

DEA Although many of the provisions of this Act have been repealed by NEMA, the

regulation on Sensitive Coastal Areas remains in force until replaced with new

regulations.

Sea Fishery Act 12 of

1988

DEA (Marine & Coastal

management)

This act includes estuaries and the estuary bed and has been used to proclaim

marine reserves along certain sections of our coast.

Conservation of

Agricultural Resources

Act (No. 43 of 1983)

Department of Agriculture This Act provides for the conservation of the natural agricultural resources of the

Republic by the maintenance of the production potential of land, by the combating

and prevention of erosion and weakening or destruction of the water sources

(including estuaries), and by the protection of the vegetation and the combating of

weeds and invader plants.



31

Table 4.2 continued


Marine Pollution (Control

and Civil Liability) Act (No.

6 of 1981)

Department of Transport

(prevention) and DEA

(combating)

This Act provides for the protection of the marine environment from pollution by oil

and other harmful substances, the prevention and combating of such pollution.

National Parks Act (No.

57 of 1976)

DEA; SANP The National Parks Act provides for the establishment of National Parks. National

Park status establishes the strongest claim to permanent protection that is possible.

Areas above and below the intertidal zone may be included in a National Park.

Lake Areas Development

Act (No. 39 of 1975)

DWA This law (rarely used since enactment) provides for the establishment of Lake Areas

(which includes estuaries). The effectiveness of this law is questionable, as only two

such areas have been proclaimed under it. Those Lake Areas are managed by the

SANP by virtue of provisions in the National Parks Act

Sea Bird and Seal

Protection Act (No. 46 of

1973)

DEA (MCM) This Acts governs the protection and control of the capture, killing and products

produced from seabirds and seals.

Hazardous Substances

Act (No. 15 of 1973

Department of Health and

Welfare

To provide for the control (including the prevention of dumping) of substances which

may cause injury or ill health to, or DEAh, of human beings by reason of their toxic,

corrosive, irritant, strongly sensitizing or flammable nature.

Physical Planning Act

(No. 88 of 1967)


Local Government

The Act provides for Guide Plans that could influence the planning and location of

storm water drains.

Seashore Act (No. 21 of

1935)

DEA/Cape Nature This Act provides that ownership of the seashore (which includes the water and land

between the low-water mark and the high-water mark in estuaries and the sea is

vested in the State. This Act still applies to certain aspects until such time as all

sections in the ICMA are enacted.

Marine Notice 16 of

2006[1]

SAMSA Dictates SAMSA policy on small vessel surveys, certification and numbering, and

skipper qualification and certification terms of the Merchant Shipping (Small Vessel

Safety) Regulations of 2002 (as amended).



32

Table 4.3 Summary of national policies (white papers) relevant to estuarine management


White Paper Year Short Description

White Paper for Sustainable

Coastal Development in South

Africa

2000 This paper sets out a policy which aims to achieve sustainable coastal development in South

Africa through integrated coastal management. The key messages of the white paper are: 1) the

value of the coast must be recognized, 2) sustainable coastal management must be facilitated;

3) the Coastal management must be co-coordinated and integrated; 4) the Government must

adopt a co-operative style of management.

White Paper on a National Water

Policy for South Africa

1997 This paper sets out the policy for the management of both quality and quantity of South Africa’s

water resources (including estuaries). The National Water Act (No. 36 of 1998) gives legal

status to this White Paper.

White Paper on Marine Fisheries

Policy for South Africa

1997 The White Paper sets out the main policy principles that the Department of environmental

Affairs and Tourism will endeavor to implement through its marine fisheries management

institutions in order to achieve this overall policy objective. The objective is to improve the overall

contribution of the fishing industry to the South Africa’s economy. The Marine Living

Resources Act (No. 18 of 1998) gives legal status to this White Paper.

White Paper on Environmental

Management Policy

1998 The White Paper contains the government’s environmental management policy and includes an

introduction that sets out the concept of environment used in the policy, the scope and purpose

of the policy, new vision for environmental policy and the mission of the DEA with respect to the

new policy, policy principles that must be applied in developing and testing policy, government's

strategic goals and supporting objectives to begin sustainable use of resources, government's

approach to governance, setting out the powers and responsibilities of the different spheres and

agencies of government and the regulatory approach to environmental management. The

National Environmental Management Act (No. 107 of 1998) gives legal status to this White

Paper.

White Paper on Spatial Planning

and Land-use Management

2001 This White Paper addresses the development of policies, which will result in the best use and

sustainable management of land, improvement and strengthening planning, management,

monitoring and evaluation, strengthening institutions and coordinating mechanisms, creation of

mechanisms to facilitate satisfaction of the needs and objectives of communities and people at

local level. Sustainable land management plans should ensure that development and

developmental programmes are holistic and comprehensive, all activities and inputs are

integrated and coordinated, all actions are based on a clear understanding of the natural and

legitimate objectives and needs of individual land users to obtain maximum consensus and

institutional structures are put in place to develop debate and carry out proposals.

White Paper on Integrated

Pollution and Waste

Management for South Africa

2002 This paper outlines a management approach that envisages pollution prevention, waste

minimization, managing the environmental impacts associated with waste and pollution,

remediating damaged environments and integrating the management of various sources of

waste. The white paper proposes a number of tools to implement the objectives, including a

legislative programme that will culminate in new pollution and waste legislation. A National

Waste Management Strategy, which will form the basis for translating the goals and objectives

of this policy into practice, has also been developed. The National Environmental

Management: Waste Management Bill will give legal status to this White Paper.

White Paper on Development

and Promotion of Tourism in

South Africa

1996 The White Paper provides the government’s stance on Tourism and describes the following:

Role of tourism in South Africa; problems around tourism; way towards a new tourism; vision,

objectives and principles; how to ignite tourism growth; roles of key players; and organizational

structures. Based on an assessment of the

problems, constraints and opportunities facing the South African tourism industry, the concept of

"Responsible Tourism" emerged as the most appropriate concept for the development of

tourism in South Africa.



33

Table 4.3 continued

4.3 LOCAL (MUNICIPAL) LEGISLATION

There are currently no municipal bylaws (a fact recognized by the Bitou IDP) governing

activities on the Keurbooms or Bitou estuaries and as such there is no legal framework

within which to enforce standards and behaviour. This includes boat registration

procedures and the wake-free zones that are indicated on the estuaries – although most

boaters conform to these restrictions, those that do not cannot be charged or fined. This

needs to be rectified as a matter of urgency and draft bylaws need to be developed and

made available for public comment. Once approved, they will be enacted under the

provisions of Section 156 of the Constitution of the Republic of South Africa. In addition,

according to Chapter 6 (Section 50) of the ICMA, municipal bylaws may include

provisions for the implementation, administration and enforcement of the municipal

coastal management programme (see Section 4.4.4). Until such time as this can be

accomplished, Eden District is investigating the feasibility of instituting their generic

bylaws for public amenities3.

Enforcement of the municipal bylaws is usually the responsibility of either

Environmental Services or Community Protection within the municipal structures.

However, it is likely that this responsibility will be devolved to CapeNature who already

3 The existing Bitou Municipality Public Ameneties By-Law does not make provision for estuaries.

White Paper Year Short Description

White Paper on the Conservation

and Sustainable Use of South

Africa’s Biological Diversity

1998 South Africa's initial response to addressing the United Nations Convention on Biological

Diversity; it specifically recognizes the importance of estuaries and commits the government to a

number of strategies to protect these areas. The strategies suggested cut across a number of

legislative sectors such as water law, resource conservation and planning. These include:

facilitating the development of appropriate legislation to secure the conservation of South

Africa’s wetlands, and to maintain their ecological and socio-economic function, promoting the

establishment of a National System of Protected Wetlands, preventing inappropriate activities

and development around wetlands, ensuring that adequate buffer strips are retained around

wetlands, recognizing the functions and values of wetlands in resource planning, management

and decision-making, determining the impact of commercial, recreational and subsistence

fishery practices on fisheries, fish, and their habitats, and develop guidelines for managing such

fisheries. The National Environmental Management Act (No. 107 of 1998) gives legal status to

this White Paper

Policy on Sustainable Forest

Development in SA

1997 This paper provides synergy to the three strains of Indigenous Forest Management, Commercial

Forestry and Community Forestry. Elements of the policy include: setting nine guiding principles,

future goals and overall policy to govern the place of forestry in the management of land, water,

and other natural resources. This paper provides policy for: industrial forestry; community

forestry; the conservation of our natural forests and woodland; South Africa's response to global

concerns about forests; research, education and training; South Africa's relationships with states

in the Southern African Development Community.



34

have the infrastructure in place (manpower and boats) to perform this function (albeit

without enforceable bylaws at present).

The Keurbooms Estuary above the N2 bridge falls within the Keurbooms Nature Reserve

and all aspects are controlled (administered) by CapeNature. This will include aspects

usually controlled by municipal bylaws such as wake free zones and boat registration.

4.4 EXISTING MANAGEMENT PLANS, DEVELOPMENT

STRATEGIES, POLICIES AND CONSERVATION INITIATIVES.

4.4.1 BITOU INTEGRATED DEVELOPMENT PLAN (2008/2009 REVIEW)

In terms of the Municipal Systems Act (Act 32 of 2000), all municipalities have to

undertake an Integrated Development Plan (IDP) process to produce five year IDPs with

legal status that supercedes all other plans that guide development at Local Government

level. The Integrated Development plan (IDP) is the key strategic plan of the municipality

and as such prioritizes projects and determines financial planning and budgets for these

projects. The EMP will need to be incorporated into the IDP so that Management Actions

Plans (MAPs) that require financial input from the municipality can be recognized and be

allocated the necessary funding.

Estuaries are not referred to at all in the IDP and nor is the Bitou River. The Keurbooms

River is only referred to in the context of being the main surface water source for

supplying the municipal demand until 2025, at which stage abstraction could be in the

region of 14.58 Ml/day. Clearly estuaries are not a priority, and the natural environment

does not feature extensively in the IDP’s main strategies, which are:

• Economic development

• Community development, social services and housing

• Spatial development

• Basic services and infrastructure development

• Financial viability

• Good governance

• Transformation and institutional development.

The only specific reference to the natural environment is under basic services and

infrastructure, where it is stated that in ensuring an adequate potable water supply to the

people of Bitou, the rivers must be monitored to ensure sufficient water levels for

ecological conservation. One must assume this includes estuaries and that it refers to the

implementation of the Ecological Reserve.

The following environmental priorities are, however, recognized:

• Natural endowment – Keurbooms is a major supply of surface water; pollution, alien

vegetation and climate change (affecting development) are challenges.

• Pollution – CO2 emissions from tourists contribute to climate change.



35

• Conservation – Bitou is home to a diverse range of plants and animals (the ocean and

rivers are mentioned but not estuaries); water conservation and poaching are

challenges.

• Waste management – capacity of landfill site is not sufficient, particularly over

holiday periods.

• Alien plants – consume vast amounts of groundwater and this can lead to shortages

for human consumption (no mention of impact in freshwater inflow and ecological

reserve requirements).

• Deforestation – reduced levels of O2 emissions contribute to climate change (no

mention of erosion and sediment loads in freshwater inflows).

Under economic development, tourism has been allocated a budget in excess of R4

million for the 2010/2011 year, of which R800 thousand is for marketing Bitou as a

tourist destination. The EMP will highlight the need for marketing the Keurbooms and

Bitou Estuaries as tourist destinations.

A SWOT analysis recognizes the opportunity provided by the forests around Bitou for

the timber and furniture industries, alien clearing (job creation) and conservation. Climate

change is viewed as a threat to human safety and sustainable development.

In a summary table in Section 6.7, the IDP states under the heading of environmental

programmes, that there is no plan or funds allocated for this. This is not encouraging

given that much of the local economy relies on the attraction that the unspoilt

environment has to visitors.

4.4.2 BITOU LOCAL MUNICIPALITY SPATIAL DEVELOPMENT

FRAMEWORK (2005)

The Spatial Development Framework (SDF) is prepared, approved and implemented

within the legislative context of the Local Government : Municipal Systems Act, 2000

(Act 32 of 2000) and the subsequent Local Government : Municipal Planning and

Performance Management Regulations (Section 4), 2001 promulgated under Section 120

of the Local Government : Municipal Systems Act, and the Western Cape Planning and

Development Act (Act 7 of 1999).

The SDF indicates, in relation to a relevant, or future, IDP, the spatial implications of the

IDP, and spatially reflects the integration of the various strategies of the IDP; and ensures

sustainability. The SDF further gives effect to Council’s vision for development (spatial

planning) and Council’s objectives and strategies with respect to land development, use

and management. The SDF needs to be aligned with, amongst others, the Provincial SDF

(see below), the Eden SDF and Spatial Development Plans (SDPs).

The following aspects of the SDF have relevance to the EMP:

• The concept of sustainable development must inform all aspects of planning.



36

• All people have the right to participate as equals in a collective development planning

process and in the decision-making processes, which determine the use of public

resources, and are furthermore entitled to fair and equal access to public facilities,

resources and opportunities.

• Extensive and effective technical consultation and public participation should be an

integral part of ongoing planning and management. Decision-making processes

should be consistent, clear and transparent.

• Settlements must sustain social equity, economic viability and ecological integrity.

This includes the edging of settlements (containing urban sprawl) to protect valuable

natural and agricultural resources.

• Natural resources are depleted and the natural environment is rapidly being degraded.

In addition, access to nature for recreation and escape is diminishing.

• Conservation Status (Figure 4.1):

- The Keurbooms Lagoon and Keurbooms and Bitou Estuaries are considered to be

critically endangered or endangered.

• Bio-regional Planning Framework4 (Figure 4.2)(informed by STEP; see Section

4.4.8):

- The area comprising the Keurbooms Nature Reserve is designated a Core

conservation area that should comprise a Type 1 Protected Area.

- The area between the two estuaries immediately above the N2 is designated a

Core conservation area comprising an area potentially available for protection

(Protected Area Type 3).

- The Keurbooms lagoon, the entire Bitou Estuary (including floodplain and

wetlands) and the remaining sections of the Keurbooms Estuary above the N2

bridge are designated as a variety of buffer zones designed to provide additional

protection to the Core Areas. The estuaries and lagoon buffer zone is inclusive of

a Core conservation area (protects ecological networks and processes).

• A Development Corridor is proposed, with land parcels on either side of the N2

between the Keurbooms Estuary and the Wittedrift Road to the west of

Kwanokuthula.

• The ecological networks and corridors identified in the Bio-regional Framework

should be used as the basis to establish an open space system for the Bitou area.

Similarly, Core and Coastal areas should be linked via ecological networks and

corridors to form a Municipal-wide open space system.

• The Keurbooms Estuary above the N2 bridge is excluded from the urban edge,

however, the lagoon, Keurbooms below the N2 bridge and entire Bitou Estuary are all

within the designated urban edge. The permissible levels of densification (dwelling

units/ha) are to be determined by the local Municipality as are areas where

densification would be deemed inappropriate.

• Under the Resource Conservation Policies, the following are applicable:

- The controls and actions governing land use are described for Core Areas and

Buffer Zones.

- Ribbon development along the coast should be prohibited, estuaries should not be

developed so as to maintain their ecological functioning and wetlands ecosystems

4 The descriptions (criteria) of various Bio-regional areas, their primary functions, and guidelines for

management and spatial planning are available in Part 5B of the SDF document.



37

should be protected so as to maintain basic functioning (large parts of the

Keurbooms/Bitou systems fall within the designated urban edge).

- Agricultural lands and practices, including those within the urban edge, are

recognized and should be maintained provided they conform to legislation (e.g.

CARA).

- Existing wastewater treatment works must be improved and maintained to ensure

water quality of the water bodies with which they are associated.

- Water conservation and demand management for residential use must be

encouraged as this impacts on availability for farmers.

• The following Spatial Framework guidelines are applicable (italics are author’s

comments):

- Conservation areas should be protected from inappropriate development.

- Prevention of pollution of rivers and wetlands by contaminated stormwater.

- Control of inappropriate farming activities on land adjacent to rivers and

wetlands.

- Public access to wetlands must be managed to ensure sustainability and limit

degradation.

- In principle, no permanent structures for human habitation are permitted below

the 1:100 year floodline, which should form the setback for urban development.

In addition, development levels should be a minimum of 300 mm above flood

levels. These guidelines take into account climate change, which includes aspects

such as sea-level rise and the increase in frequency and intensity of flood and

storm events.

- Management strategies5 must allow for the conservation of sensitive areas.

- Rehabilitation of degraded natural systems should be undertaken where feasible.

- Allow for continuous flow of all culverts, river crossings and channels

- Infilling and dumping on floodplains and wetlands should be prevented.

- Rivers (presumably including estuaries) and associated terrestrial ecosystems

should be managed holistically.

- Sensitive areas, for the purpose of evaluating development proposals, include land

within 50 m of the high water mark, land under the 1:100 year floodline, declared

conservation areas, land of biological/scientific value, land with high to medium

agricultural value and areas containing aquifers or groundwater resources.

- Evaluation of development and rezoning applications within the urban edge must

take the following into account:

� Opportunities to enhance or retain environmental qualities.

� Assessment of physical aspects of the environment.

� Assessment of functioning of the biophysical and ecological environment and

protection of sensitive areas.

� Activities must ensure the least amount of environmental degradation.

� Impacts on the hydrological cycle in the catchment must be minimized.

� Impacts on sensitive environments must be limited to those that can be

mitigated and only if this is feasible and enforceable.

� Visual integrity of scenic assets must be reinforced.

5 This would include the Estuary Management Plan.



38

Figure 4.1 Conservation status of the Bitou Municipal Area.

CONSERVATION STATUS

BITOUMAP 11

CONSERVATION STATUSCritically EndangeredEndangeredVulnerableCurrently Not VulnerableDECEMBER 2004



39

Figure 4.2 Bio-regional Framework of the Bitou Municipal Area.

BIOSPHERE SPATIAL PLANNING CATEGORY C: TRANSITION AREAS (Spatial Planning Categories C: Agriculture, D: Urban-Related, E: Industry, F: Surface Infrastructure and Buildings)Transition Areas (Non-Destructive/Destructive Activities) (STEP Class: IV) (STEP Description: Currently not Vulnerable)

BIOSPHERE SPATIAL PLANNING CATEGORIES B AND C: BUFFER AND TRANSITION AREASBuffer Areas (Non-Destructive Activities) / Transition Areas (Non-Destructive/Destructive Activities) (STEP Class: III) (STEP Description: Vulnerable) (Impacted/Disturbed Areas)

BIOSPHERE SPATIAL PLANNING CATEGORY B: BUFFER AREASBuffer Areas (Restoration) (STEP Class: I) (STEP Description: Critically Endangered) (Impacted/Disturbed Areas)Buffer Areas (Restoration) (STEP Class: II) (STEP Description: Endangered) (Impacted/Disturbed Areas)

BIOSPHERE SPATIAL PLANNING CATEGORY B: BUFFER AREAS INCLUDING CORE AREASBuffer Areas including Core Areas (STEP Description: Ecological Networks and Processes)

BIOSPHERE SPATIAL PLANNING CATEGORY A: CORE AREASCore Areas (STEP Description: Protected Areas Type 1) (Owned and managed by the State, Province or a Local Authority - Conservation legislation is strong)Core Areas (STEP Description: Protected Areas Type 2) (Public or private land used for conservation and other land uses - Conservation legislation is weak or non-existent)

Core Areas (STEP Description: Protected Areas Type 3) (Areas potentially available for conservation)

MAP 1

BITOUBIOREGIONAL FRAMEWORK

DECEMBER 2004



40

4.4.3 WESTERN CAPE PROVINCIAL SPATIAL DEVELOPMENT

FRAMEWORK (PSDF)

The purpose of the PSDF, an integrated provincial wide framework, is to;

• Be the spatial expression of the Provincial Growth and Development Strategy

(PGDS);

• guide (metropolitan, district and local) municipal integrated development plans

(IDPs) and spatial development frameworks (SDFs) and provincial and municipal

framework plans (i.e. sub-SDF spatial plans);

• help priorities and align investment and infrastructure plans of other provincial

departments, as well as national departments' and parastatals' plans and programmes

in the Province;

• provide clear signals to the private sector about desired development directions;

• increase predictability in the development environment, for example by establishing

no-go, conditional and ‘go’ areas for development; and,

• redress the spatial legacy of apartheid.

With regards taking climate change into account, the PSDF states that:






This guideline has specific applications when it comes to developments within the

defined estuarine area, and in particular within the lower reaches of the Keurbooms

below the N2 which is heavily developed within both the 1:50 and 1:100 year floodlines,

and the Bitou above the N2, which is characterized by extensive floodplains.

4.4.4 GARDEN ROUTE INTIATIVE

The Garden Route Initiative (GRI) was established in 2004 with the aim of improving the

coordination of conservation actions between several organizations in order to achieve a

common goal. The objectives of the GRI are to identify priority biodiversity areas,

consolidate protected areas, promote conservation stewardship, incorporation biodiversity

priorities into land use planning and decision making and to ensure the sustainable

management effectiveness of the Garden Route conservation areas. In order to achieve

these objectives the GRI seeks to develop systems and structures that would enhance

communication, cooperation and coordination between stakeholders involved in

conservation activities within the area.



41

4.4.5 A CLIMATE CHANGE STRATEGY AND ACTION PLAN FOR THE

WESTERN CAPE (DRAFT)

This Draft document (DEADP 2007) outlines a strategy (adaptation and mitigation) to

deal with the effects of climate change in the province. Vulnerable systems (areas)

include natural systems (water, biodiversity, and coastal and marine systems and

resources, economic sectors (agriculture, tourism and fisheries), economic resources and

infrastructure (energy, transport, health and air quality) and the built environment,

livelihoods and disasters (social systems and extreme events such as floods and fires). In

order to deal with these consequences, the strategy and action plan details the following

prioritized programmes or key outcomes (most of which are applicable to the estuary

management scenario):

• An integrated water supply and infrastructure management programme that integrates

climate impacts and risks. This involves researching the cost benefit of irrigation,

increasing water efficiency including through pricing strategies, establishing

uninterrupted water conservancy targets, systems maintenance and repairs and

establishing the ecological reserve.

• Establishing clear links between land stewardship, livelihoods and the economy. This

entails effective land use and land care; protection, maintenance and enhancement of

natural resources; strengthening vulnerable communities and protecting livelihoods

through targeted research; maintaining diversity in the economy; and integrating

climate risks into development planning.

• Establishing a focused climate change research and weather information programme.

• Reducing the Provincial carbon footprint. This can be achieved through energy

efficiency, development of renewable and alternate sustainable energy resources,

effective waste management strategies and cleaner fuel programmes for households

and transport.

4.4.6 COASTAL MANAGEMENT PROGRAMME

The development of Coastal Management Programmes (CMPs) is a requirement under

Chapter 6 of the ICMA. Sections 48 to 50 specifically make provision for municipal

CMPs, which would include estuaries. Essentially the EMP for the Keurbooms and Bitou

Estuaries would need to be integrated with the municipal CMP, which in turn may be

adopted as part of the IDP. Eden District has just initiated its CMP and it will be

developed over the next two years. Aspects of a CMP that are applicable to the estuary

environment include:

• Coastal Action Plans (CAP) need to be developed for pollution control & waste

management, natural resource management and awareness & education.

• A Coastal Working Group (or management committee) needs to be structured to

include all major stakeholder groups and senior managers, and their TOR need to be

formalized.



42

• Land use and management guidelines must be developed in accordance with the

ICMA regulations.

• No development within dynamic coastal process areas (includes estuarine area) unless

for the purpose of protecting those areas.

• Inappropriately located infrastructure should be relocated and/or demolished.

• Management plans need to be developed for all conservation areas.

• Increase capacity of conservation staff (both numbers and education).

• A resource economics study is required to guide decision-making.

• Reserve determinations must be conducted for all estuaries.

• Abstraction rights from riverine systems need to be reviewed.

• Those responsible for environmental degradation must be held liable for rehabilitation

(polluter pays principle).

• Illegal waste disposal and littering needs to be minimized via pro-active and reactive

means.

4.4.7 CAPE ACTION FOR PEOPLE AND THE ENVIRONMENT

The C.A.P.E. is a project developed in partnership with the Global Environment Facility

(GEF) to secure the future of the Cape Floral Kingdom (also known as the Cape Floristic

Region). The C.A.P.E. project was made possible by a grant from the GEF and

established to develop a long-term strategy to conserve biodiversity in the terrestrial,

marine and freshwater ecosystems of the Cape Floral Kingdom (Table 4.4). The C.A.P.E.

project has a dedicated estuary management programme, which coordinates the

development of EMPs (including this one for the Keurbooms and Bitou Estuaries) within

the CFR.

Table 4.4 Themes and Strategic Components of C.A.P.E. (after DMP 2004).

THEMES STRATEGIC COMPONENTS

Conserving biodiversity in

priority areas

a) Strengthening on- and off-reserve conservation

b) Supporting bioregional planning

Using resources sustainably

a) Conserving biodiversity and natural resources in catchments

b) Improving the sustainability of harvesting

c) Promoting sustainable nature-based tourism

Strengthening institutions and

governance

a) Strengthening institutions

b) Enhancing co-operative governance

c) Promoting community involvement

C.A.P.E. has produced a Strategy and Action Plan, specific objectives of which include

the following (after DMP 2004):

• Establishing an effective reserve network, enhancing off-reserve conservation, and

supporting bioregional planning.

• Developing methods to ensure sustainable yields, promoting compliance with laws,

integrating biodiversity concerns into catchment management, and promoting nature-

based tourism.



43

• Strengthening institutions, policies and laws, enhancing co-operative governance and

community participation, and supporting continued research.

4.4.8 SUBTROPICAL THICKET ECOSYSTEM PLAN

(Description taken from DMP 2004)

The Subtropical Thicket Ecosystem Plan (STEP) was a three-year project co-funded by

the GEF to identify priority areas for conservation actions in the thicket biome and to

ensure that national, provincial and local authorities implement the conservation plan.

The STEP project focuses on the core area of the Thicket Biome, which occurs between

the Groot-Gouritz river system in the west, the Kei River in the east, and the Great

Escarpment in the hinterland in the vicinity of Graaff-Reinet in the west to Queenstown

in the Eastern Cape.

The region includes the Albany Centre of plant endemism and overlaps in the west with

the Succulent Karoo Centre. Both are centres of diversity and endemism for succulents

and bulbs and are floristically the most important parts of the Thicket Biome. The

Albany Centre is a recognized WWF-IUCN global centre of plant biodiversity, and

nearly all of its plant endemics are components of the Thicket Biome. The Thicket

Biome in this region is thought to contain the most species-rich formations of woody

plants in South Africa. It overlaps with the Cape Floristic Region, which is the subject of

a major strategic conservation planning exercise.

The overall aim of STEP is to:

• Provide a detailed spatial analysis of the various thicket types.

• Assess the extent of their transformation and develop a better understanding of the

threats.

• Locate and design conservation areas to achieve explicit representation goals.

• Suggest and prioritize explicit conservation actions.

• Provide information for incorporation into regional Structure Plans and national

Environmental Management Frameworks.

• Provide a capacity building service in GIS-based conservation planning.

• Guide investors from the public and private sectors in the selection of land for

commercial enterprises, e.g. game-based ventures.

• Create an awareness of the value and plight of the Thicket Biome.

4.4.9 EDEN TO ADDO CORRIDOR INITIATIVE

The Eden to Addo Corridor Initiative aims to assist landowners to identify and develop a

living corridor from Eden to Addo by applying sound land-use practices, encouraging a

diversity of livelihoods and linking ecologically important areas, for the benefit of

wildlife and the extended community (Eden to Addo 2010). There are several initiatives

located in the upper and middle catchment regions of the Keurbooms and Bitou Rivers,

but the most pertinent initiative (in terms of the estuary) is that associated with the Bitou



44

Wetland, which is seen as a vital corridor between the SANParks Forest Reserve and the

Keurbooms Nature Reserve. Initially, there appeared to be an overwhelming level of

support for this initiative, but recent developments (see Eden to Addo 2010; Section

3.3.1) have resulted in a rift between some landowners and Eden to Addo and the

initiative has been severely compromised. The future remains uncertain.

4.4.10 EXISTING MANAGEMENT PLANS (FRAMEWORKS)

There is currently no management plan for the Keurbooms/Bitou Estuaries. However,

management related issues are currently dealt with by relevant government departments;

primarily CapeNature, DWA, DAFF, DEADP and various municipal departments. There

is currently no environmental officer within the Bitou Municipality and the Eden District

official has to fulfill these obligations. This is less than ideal and needs to be rectified as a

matter of urgency. Local civil society organizations have had two management

frameworks drafted for different regions associated with the estuaries. These are

described below.

Keurboomstrand Preliminary Environmental Management Framework

The Keurbooms Property Owners Association privately funded this framework (Grant

Johnston Associates 2008) in order to identify critical or sensitive environments and raise

the general awareness about their importance and help guide future planning of

developments. Of particular relevance to the proposed EMP are the wetlands, specifically

saltmarshes and the Tshokwane River wetlands (located to the east of the Keurbooms

Estuary and seaward of the N2) that drain into the Keurbooms Estuary near the

Strandmeer Estate. Barriers to the natural drainage of this wetland into the Keurbooms

threaten to restrict freshwater flow into the system and further impacts could be

detrimental to overall ecosystem functioning. Other environments that may fall within the

defined estuary area, and therefore will need to be considered in the EMP are Knysna

afromontane forest, coastal forest and dune thicket, fynbos and coastal dune systems

(comprising foredunes, primary dunes, dune slack and secondary dunes). Reference is

also made to restricting development within certain zones, including the 1:50 year flood-

line (3.2 m above MSL), 100 m from the high water mark and below the 5 m contour.

The report also provides GIS maps of topography, ecosystems, ecological corridors and

sensitivity.

Lower Bitou/Keurbooms Catchment and Floodplain: Preliminary Environmental

Management Framework

The Plettenberg Bay Community Environment Forum privately funded this framework

(Grant Johnston Associates 2009) in order to identify critical or sensitive environments

with the aim of providing a framework within which appropriate development can be

assessed in the future. The report also provides GIS maps of topography, ecosystems,

ecological corridors and sensitivity. In terms of sensitivity, the report highlights both high

and moderate areas, many of which are applicable within the context of the proposed

EMP. These include wetlands and rivers, indigenous coastal forest and thicket, land

below the 5 m contour (all High) and areas with mixed alien trees (Moderate). Additional

ecosystems of note are fynbos and grassland (more catchment related), dune systems and



45

coastal corridors on a larger scale. Three key environmental issues are identified, namely

climate change (includes sea-level rise and storm/flood events), water abstraction from

the Keurbooms River by the Bitou Municipality (includes reference to and

recommendations from the Rapid Ecological Reserve study by CSIR in 2008) and land

management within the catchment and floodplain (defined as area below 5 m contour).



46

CHAPTER 5 – RECREATIONAL USE

5.1 EXPLOITATION OF LIVING RESOURCES

5.1.1 KING ET AL.

A fishery survey on the Keurbooms and Bitou Estuaries by King et al. (in prep.) from

September 2003 to August 2004 (roving creel surveys for 3 days each month, including 2

week days and a week-end day or public holiday) revealed the following:

• A total of 1 630 anglers were encountered during 32 sample days, of which 277 were

subject to detailed questionnaires and an additional 160 to catch inspections.

• The fishery is male dominated (92%)6 and comprised 68% whites, 38% coloured and

1% black.

• 48% of the participants are local (living within 30km of the estuaries).

• 68% were formally employed while only 9% were currently unemployed.

• Recreational shore-based anglers comprised 46% and boat-based anglers 52%7; only

2% were classified as subsistence8.

• 86% of anglers were not affiliated to any club.

• Subsistence anglers fish for substantially longer periods per outing (>9 hrs) than

shore- or boat-based anglers, who average approximately 3 hrs 30 min. 42% of

anglers undertake night-fishing outings as well.

• Effort is higher on weekends and public holidays for recreational anglers but no

difference was noted for subsistence users. Angler counts peak during the Christmas

and Easter holidays. An estimated 64 367 angler hours were fished during the survey

period.

• Effort was highest below the N2 road bridges for all sectors, with the confluence

region being a key focal point.

• Catch-per-unit-effort (cpue) was highest for boat-based anglers (0.07

fish/angler/hour) followed by subsistence anglers (0.03) and shore-based anglers

(0.02). Overall average cpue was 0.04 fish/angler/hour and total estimated harvest for

the survey period was 19 452 fish (6 573 kg).

• Only 32% of anglers catch at least one fish per outing and only 4% ever attain or

exceed the bag limit for a species (mostly R. holubi).

• Fourteen species were recorded in catches, of which Cape stumpnose was

numerically dominant (47%) followed by spotted grunter (25%) and white steenbras

(8%). Spotted grunter dominated the catch by weight (52%) followed by Cape

stumpnose (13%) and white steenbras (11%).

6 This may have changed as anecdotal information suggests that many more woman are now active.

7 Includes power driven vessels, canoes/fishing skis and rowing boats.

8 Note that although classed as subsistence in the survey, due to unemployment status or reliance on fish as

a food source, these anglers are not in possession of valid subsistence permits issued in terms of the MLRA.

According to Clark et al. (2002) there are between 50 and 60 subsistence fishers – this number is likely to

be somewhat larger by now.



47

• The majority of fish caught were under the minimum legal size; 77% of Cape

stumpnose, 51% of spotted grunter and 100% of white steenbras. Sample size for

dusky kob (4) and leervis (5) were small but one and all were undersize respectively.

• 59% of anglers use bait collected exclusively from the estuaries; 13% use bait

collected and bought from retailers; 21% use bait exclusively bought from retailers;

4% used bait bought illegally from subsistence collectors9 and 3% used artificials.

10

• Most commonly used bait includes sandprawn (26%), pilchard (23%), mudprawn

(22%) and pencil bait (11%). The estimated harvest for sand and mudprawns over the

survey period was 199 891 and 185 742 respectively (no standing stock data is

available to estimate the proportion taken by collectors), with the majority of effort

being in the Poortjies area and adjacent to the caravan park in the mouth region.11

• Angler perceptions were that abundance and mean size of bait organisms has

declined, with 30% attributing this to over exploitation. Knowledge of bait

regulations was poor, with only 40% knowing the legal quota and 44% being in

possession of a permit.

• Knowledge of the fish regulations was also poor, with only 23% of anglers providing

correct minimum size limits for their target species. Minimum sizes also received the

lowest score in terms of effective regulations.

• Compliance monitoring effort appears to be low, with 72% of anglers never having

had their catches inspected. The frequency of inspection for 34% of those who have

been monitored is less than once in every 50 outings.

• 74% of anglers thought catches had decreased over time (catch rate and average size)

with A. japonicus, P. commersonnii and L. lithognathus being the most noteworthy.

• The high percentage of undersize fish kept by anglers was viewed as a major concern,

and an increase in compliance monitoring efforts combined with an awareness raising

campaign is strongly motivated.

5.1.2 ANECDOTAL INFORMATION

Anecdotal information gathered from stakeholders during site visits and meetings

between 11 and 13 February and 3 and 5 March revealed the following about the fishery:

• The fishery is diverse, comprising shore and boat-based anglers using a variety of

gear types (rod & reel and handlines).

• Up to 30 power driven boats may be active on the estuary per day during the year, but

during holiday season this may increase to between 300 and 400. The number of

boats registered by CapeNature for the past three years are 631, 566 and 583.

Although not all are involved with fishing activities, many will be.

9 Numbers of illegal bait sellers are not known, but they tend to ply their trade in the region of the N2

bridge over the Bitou, particularly during peak holiday periods (Henk Nieuwoudt, CapeNature, Pers.

Comm.). 10

Note that since the survey period it is likely that a greater percentage of anglers use artificials such as fly

and dropshot as this format has increased in popularity (and effectiveness) in recent years. As such, the

catch composition is likely to have changes as well, e.g. more dusky kob and leervis. 11

Observations during a site visit (11-13 February 2010) revealed a high collecting effort in the Bitou

estuary below the N2 bridge and around the Anath peninsula.



48

• There are between 30 and 40 rowing boats used by fishermen mainly from New

Horizons with effort concentrated in the lagoon area.

• It is estimated that in excess of 150 and 100 anglers from New Horizons and

Wittedrift respectively fish in the two estuaries and lagoon; many of these are women.

Average time spent fishing by these members if 8 hours per outing, with those who

are employed fishing either at night during the week (shorter periods) or over

weekends. Effort is divided between the estuaries and the sea depending on where

fish are being caught. Sandprawn, mudprawn and pilchards (bought) are the dominant

bait items.

• Most effort (all user groups) is during daylight hours and below the N2 bridges, but a

large number of Wittedrift anglers fish between the N2 and old destroyed bridge on

the Bitou.

• Despite regular inspections by CapeNature officials, many anglers admit to keeping

undersize fish as this is a primary food source, particularly amongst the Wittedrift and

New Horizons communities.

• More dusky kob is being caught than previously due to use of artificials, particularly

in upper reaches above Whisky Creek (see footnote 6).

• Juvenile leervis present all year, with larger specimens in February/March.

• Elf present between November and April.

• Predominantly juvenile white steenbras are caught in the estuary.

• Skipjack present during warmer months and returning after a long absence.12

• There is a consensus that fishing has improved since the 2007 floods and that this was

good for the system.

• Illegal bait collecting methods (digging) is not prevalent, but illegal selling does take

place; prices are not fixed and fluctuate depending on demand. Some white anglers

pay New Horizons and Wittedrift community members to collect bait on their behalf

– mostly sandprawn, mudprawn and bloodworm.

• A charter operation takes clients fishing and promotes a catch-and-release ethic; all

forms of angling (bait, fly and artificials) are offered.

• Catches indicate that the systems are in good condition (health) at present.

• The availability and proposed price increase of recreational licenses was viewed as

problematic and in need of attention.

• Education and awareness programmes are required to inform users about regulations

and the importance of the estuaries in general.

• Conflict between user groups is not considered to be a major concern, although

speeding boats do pose a safety risk (to fishers in small rowing boats) and also snag

fishing lines.

• No-take sanctuary zones were recognized as important but site selection needs to be

based on sound scientific data.

• No fishing competitions take place on the estuary and stakeholders felt that this

should not change.

12

This is a trend observed in other permanently open estuaries such as Swartkops, Kariega and Bushmans.



49

5.1.3 LICENSED SUBSISTENCE FISHERS

According to the Marine Living Resources Act (Act 18 of 1998; MLRA), Schedule 1,

Section 1 (lv), a subsistence fisher is defined as, “a natural person who regularly catches

fish for personal consumption or for the consumption of his or her dependants, including

one who engages from time to time in the local sale or barter of excess catch, but does not

include a person who engages on a substantial scale in the sale of fish on a commercial

basis.”

There are 65 subsistence exemptions (permits) that have been granted to fishers in The

Craggs for the year 2010 (expires 31 December 2010). These exemptions have been

issued in terms of Chapter 3, Part 2 (Section 19) of the MLRA, and allow for the catch

and sale of certain linefish species, both in the marine and estuary environment. There are

strict conditions linked to the permit, such as bag limits, size limits, species that may or

may not be sold and the use of boats. The permit does not allow for the sale of bait

organisms. The Keurbooms and Bitou are two of the closest estuaries to the The Craggs,

and as such may be utilized by these permit holders on occasion. For the most part,

however, these fishers fish in the marine environment. According to MCM records there

are no subsistence permits granted to any fishers residing in the communities (e.g.

Wittedrift and New Horizons) close to Plettenberg Bay.

5.2 TOURISM AND NON-CONSUMPTIVE USE

A host of non-consumptive activities take place primarily on the lagoon and Keurbooms

Estuary. The Bitou Estuary is not easily accessible by boat above the N2 bridge, and

although the floodplain and wetland complex has potential to be a premier bird watching

area, access through privately owned land is problematic. Landowners are willing to

allow members of the public access but need assurances that their property will be

respected – incidences of fires and littering have occurred in the past.

Plettenberg Bay and its surrounds are one of the major tourist destinations in South

Africa, attracting both local and overseas visitors. Despite this, the Keurbooms is not

specifically marketed as a destination but is usually included amongst other marketing

packages that incorporate the greater Plettenberg Bay area or the Garden Route. This was

recognized as a potential opportunity during a meeting with tourism stakeholders (March

3rd

) and the EMP will address the possibilities of marketing the area as a destination – a

joint venture between operators and Bitou Tourism).

Several resorts are available to the visitor, including the Keurbooms Lagoon Caravan

Park, Forever Resorts, the Keurbooms River Lodge (Protea Hotel) and the up market

Stanley’s Island. Numerous B&Bs and guesthouses also provide accommodation. Many

tourists own property close to the estuaries and are frequent visitors throughout the year.

There are also a large proportion of permanent residents who choose to live here.



50

Activities that take place include:

• Appreciating nature – includes rest and relaxation, swimming, walking, canoeing,

power boating (slow cruises), bird watching and picnics (three sites in the upper

reaches of the Keurbooms administered by CapeNature). Guided tours with an

educational slant (wildlife, history) are offered on board two motorized barges.

• Water sports – predominantly water skiing above the N2 bridge on the Keurbooms

Estuary. Kite boarding, windsurfing and sailing may also take place (lagoon area).

• Sporting events – although the SA National Canoeing Championships have been held

on the Keurbooms there is considerable potential for it to host additional events such

as open water swimming, rowing and sailing (in the lagoon area).

Potential activities identified during stakeholder meetings include:

• Formal walking trails through the Keurbooms Nature Reserve in the middle to upper

reaches of the Keurbooms Estuary.

• Educational workshops for school groups (possible venue is Anath Peninsula) to

create an awareness of the importance of estuaries.

• Snorkeling trails linked to the Knysna seahorse.

• Additional sporting events (see above).

• Package holidays that include a variety of activities associated directly with the

estuaries or indirectly, e.g. golf at Goose Valley.



51

CHAPTER 6 – WATER QUANTITY AND QUALITY

6.1 INTRODUCTION

This section of the Report focuses on the contribution of freshwater systems to the

maintenance of the Keurbooms and Bitou Estuaries. Current pressures on freshwater

systems include increased abstraction volumes to supply agricultural and domestic needs

within the Bitou Municipality, driven by an increase in development both in the formal

and informal housing sectors, together with the required infrastructure. A number of golf

and polo (equestrian estates) are also found within the management area.

6.2 MANAGEMENT OF THE CATCHMENT

The Keurbooms/Bitou catchment’s management structures consist of a number of

national, local and municipal structures. These can be listed as follows:

• Department of Environmental Affairs, inclusive of the Directorate Marine and Coastal

Management on a national level.

• Western Cape Department of Environmental Affairs and Development Planning at the

provincial level.

- Responsible for the management of the estuarine area, including ensuring

compliance in terms of the MLRA (e.g. subsistence and recreational fishing).

• Department of Water Affairs (previously known as the Department of Water Affairs

and Forestry) at the national and provincial level.

- Responsible for all water-related issues, i.e. catchment management, Resource

Directed Measures (RDM) for protection of freshwater resources (i.e. determining

Ecological Water Requirements (EWR) and setting the Reserve), planning,

infrastructure, monitoring river health, enforcing discharge standards and dam

safety etc.

• Other national and provincial offices of departments/directorates, e.g. Agriculture,

Forestry, Tourism and Land Affairs.

• Bitou Municipality within the Eden District Municipality.

- As the delegated authority the municipality is currently responsible for the overall

management of the Bitou/Keurbooms systems.

6.3 CATCHMENT DESCRIPTION

The Keurbooms and Bitou river catchments are located in the Gourits Water

Management Area (WMA) 16. The catchments of these two rivers have been measured at

1 085 km2 (Day 1981), 1 188 km

2 (Heydorn and Tinley 1980) and 1 270 km

2 (Haigh and

Bekker 2005) respectively, with the Keurbooms being estimated at 70 km in length

(James and Harrison 2008) and the Bitou River at 23 km from its confluence with the

Keurbooms to its head (Bornman and Adams 2005). The river systems extend from the

Witberg and Tsitsikamma mountains in the North to the coast in the South, with the

Keurbooms having few floodplain areas as it is located within incised river gorges for



52

most of it length. The Palmiet River is the principal tributary of the Keurbooms and

originates in the K60D quaternary catchment.

The rivers drain the K60 catchment (Figure 6.1), which includes quaternary catchments

K60A, B C, D, E and F. A small tributary which falls within K60G also forms part of the

Bitou catchment, and flows directly through the Plettenberg Bay Sewage Treatment

Works (STW) at Gansevalei. After passing the reclamation ponds of the STW, the Ganse

Spruit flows through wetlands and water features of the Goose Valley golf course and

then onto the large Ganse Spruit wetland (also known as Ganse Vlei or Gansespruit Vlei),

with any resultant flows entering the Bitou Estuary. It should be noted that the Piesang

River also forms part of K60G, but forms part of an independent catchment and estuary

and not part of this study.

Figure 6.1 Locality map indicating the various quaternary catchments associated with the

Keurbooms / Bitou rivers (from Haigh and Bekker 2005).

Table 6.1 summarizes the main tributaries found associated with the Keurbooms/Bitou

quaternary catchments and the Mean Annual Precipitation (MaP) values (Haigh and

Bekker 2005), with the exception of K60G as discussed above.



53

Table 6.1 Details of the quaternary catchments of the Keurbooms catchment K60.

Quaternary

catchment

Size Ha (km2) MaP (mm) Rivers/ streams

K60A 16 145 (162) 664 Kykoe, Kleinbosloop, Bos, Jaggakamma, Pieters, Keurbooms River exits

K60B 14n317 (143) 754 Voogds, Kwaai, Witels, Keurbooms River exits

K60C 16 081 (161) 744 Jakkalskraal, Uitvlugt, Diep, Klein, Keurbooms River exits

K60D 29 247 (292) 815 Kleinpalmiet, Langbos, Keur, Soetkraal, Dwarsrivier, Tarkakloof, Palmiet River exits

K60F 24 207 (242) 806 Rondbos, Kransbos, Petrus Brand, Ouhoogte, Leermansdrif, Bosfontein, Diep, Bitou

River exits into Keurbooms Estuary

K60E 10 017 (100) 775 Duiwelsgat, Whiskey Creek, Keurbooms Estuary

Source: WR90

Plettenberg Bay receives rainfall all-year-round with peaks in autumn (March/April) and

spring (August to November; Figure 6.2). The higher rainfall for Plettenberg Bay in

spring (dominant rainfall period) is a product of the late winter frontal systems together

with the effect of orographic rain resulting from the proximity to the coastal mountains.

The rain is mainly cyclonic and orographic, while thunderstorms are rare. Winter rainfall

is associated with the increase in cold fronts (east moving cyclones) passing over the

coast (Bornman and Adams 2005).

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Month

25

30

35

40

45

50

55

60

65

70

75

80

85

Me

an

ra

infa

ll (

mm

)

Mean annual precipitation 1984 - 2003 = 671 mm

Figure 6.2 Mean monthly precipitation over 20 years from 1984 to May 2004.



54

The only major dam in the catchment is the Roodefontein Dam, which was raised to

2x106 m

3 capacity in 2003. Environmental releases of 0.31x10

6m

3 are made from this

dam to meet requirements at IFR5 downstream of the confluence of the Keurbooms and

Palmiet rivers. Values were taken from the 1996 Keurbooms IFR study. Farm dams are

mostly situated in the Upper and Lower Keurbooms River and Piesang River. The Bitou

Municipality’s water sources are shown in Table 6.2 (Anonymous 2006).

Table 6.2 Present and future water sources of the Bitou Municipality.

Town Current source of supply Future source of supply

Plettenberg Bay Pumping from the Keurbooms River, just below the

confluence with the Palmiet; Roodefontein Dam (also

irrigation abstraction for Jakkalsdraai); and six inland

boreholes (although saline intrusion limits use).

Off-channel storage adjacent to Keurbooms River.

Raise Roodefontein Dam + increase pumping from

Keurbooms during high demand periods.

Keurboomstrand Keurbooms aquifer via wells and boreholes. Off-channel storage in Matjies River. Share of Bufels

River Dam. Obtain water directly from Plettenberg Bay

works.

Kurland Small pool in Wit River, run-of-river abstraction. Unknown

Nature’s Valley Natural pool in Groot River; run-of-river pumping

scheme.

Unknown

Land-use in the upper catchment is predominantly natural forest, mountain fynbos and

grasslands, while the middle and lower catchments are used more extensively for

agriculture, residential and recreational purposes. No significant increases in irrigation,

forestry or farm dams are expected up to 2025 (Anonymous 2006).

The topography of the Keurbooms/Bitou area is dominated by the low-lying estuary and

its floodplain, while the inland reaches and upper catchments are dominated by

mountainous valleys and ridges. Figure 6.3 represents the middle and lower reaches of

the Keurbooms and Bitou Estuaries, inclusive of the Keurbooms Lagoon.

6.4 ECOLOGICAL STATUS

6.4.1 RIVERS

Biological monitoring activities of the Keurbooms and Bitou rives were undertaken as

part of a provincial initiative between DWA and CapeNature in order to fulfill the

objectives of the national River Health Programme (RHP). The RHP has the overall goal

of delivering ecological information about rivers (and link up with other aquatic

ecosystems, wetlands and estuaries monitoring initiatives), required to support the

national management of these systems. The RHP is designed to develop the capacity and

information base required to enable DWA and other role players to report on the

ecological state of South Africa’s river systems, in an objective and scientifically sound

manner. The information products generated by the RHP assist in distinguishing between

aquatic ecosystems exposed to sustainable utilization and those experiencing ecological

deterioration. It also allows for subsequent audits of management strategies and actions



55

implemented to improve or maintain the ecological status of aquatic ecosystems. The

RHP determines the ecological state of river ecosystems in South Africa by evaluating

physical drivers such as geomorphology, water quality and habitat integrity, as well as

biotic indicators such as fish, macroinvertebrates and riparian vegetation. Two national

RHP sites are found on the Keurbooms River.

Figure 6.3 The middle and lower reaches of the Keurbooms Estuary (after Bornman and

Adams 2005).

A field survey of one of the national RHP Keurbooms sites, and a site on the Bitou River,

was undertaken by the CapeNature River Conservation Unit in the Gouritz WMA during

23 – 27 November 2009. The second national RHP site was inaccessible and could not be

monitored. Intensive monitoring of sites in the Gouritz WMA will commence in the

2011/2012 financial year. Results of the November survey are shown below. Indices used



56

for the assessment were the geomorphological index (SASS5) for macroinvertebrates and

the Index of Habitat Integrity (IHI; DWA 2009).

Keurbooms River RHP site: K6KEUR-RHINO

The site is situated at the Rhino base camp at the DWA weir (33056’19.3’’ S;

23021’58.3’’ E), but could not be accessed due to very steep banks. A site was selected

approximately 100m upstream of the original site at a low water bridge.

• Macroinvertebrates (SASS5): This site is characterized by a high species diversity,

with a high sensitivity score. The results show that this site is in a Natural condition.

• Geomorphology: The Geomorphological Index (GI) shows that this site is in a C

category in terms of its geomorphological state. Clearing the recruits of black wattle is

needed and would require effective management.

• IHI: A number of abstraction pipes were seen at the site, with serious modifications to

the non-active channel, e.g. road construction, bridges, bulldozing and debris, and

infestation by alien trees. A large portion of the left-hand bank has been modified. A

moderate infestation of alien vegetation was seen in the riparian zone.

Bitou River site: K6BITO-WITTE

The site is at the head of the estuary at the road bridge and causeway at the Wittedrift

turning (33º59’58.4” S; 23º20’27.5” E).

• Macroinvertebrates (SASS5): SASS5 was not undertaken as suitable biotopes were

not available for sampling.

• Geomorphology: No results shown in DWA (2009).

• IHI: Modification of flow evident by two water abstraction devices and two bridges

(road bridge and old low bridge/causeway). The riparian zone appeared highly

susceptible to erosion.

6.4.2 CONCLUSION

The Keurbooms catchment has received little attention in terms of long-term monitoring,

with the focus being almost entirely on the estuary.

6.5 WETLANDS

A large number of freshwater wetlands are found within both the river catchments, with

58 wetlands surveyed by Haigh and Bekker (2005). Storage in farm dams and direct

abstraction for fruit farming, pasture cultivation, forestry and alien plant infestations,

have resulted in the degradation of several wetlands. These impacts have also resulted in

the disturbance of the riparian zones within the catchments.

Quaternary catchment K60D was rated as having the highest number of wetlands and

river-associated riparian systems that remain in a good condition, while K60E was the



57

poorest with a large plantation block (Keurbooms State Forest) being cultivated directly

within the wetlands, and resulting in eroded areas. As catchment K60D is the principal

water source for the Keurbooms and Bitou Estuaries, the maintenance of its wetlands are

of paramount importance. The largest wetlands are found within K60F, i.e. the Bitou

catchment (Haigh and Bekker 2005).

6.6 WATER QUANTITY

Thirteen gauging stations or plates have been used to record flow data for various periods

starting in 1961. These are mostly located along the upper and lower reaches of the

Keurbooms River. Table 6.3 indicates the monthly volumes recorded at the Newlands

gauging weir (K6H019A01 - 33° 56’ 45" S 23°22' 03" E) on the Keurbooms River for the

period 1997 to present. Peaks in run-off volumes are evident throughout the year.

Although the estuary is flood tide dominated, with the scour by tidal flows removing

wave deposited sand to maintain the inlet channel and allow tidal exchange, river floods

also have an important function. These floods temporarily scour open inlets and remove

tidal-accumulated sediment from the lower reaches of the estuary (Reddering 1981;

1999).

Past studies (Duvenhage and Morant 1984) have noted that the Mean Annual Runoff

(MAR) of the Keurbooms River was highly variable and mirrors rainfall in the region.

However, all studies agree that the lowest runoff is recorded at times when the water

demand is highest.

Table 6.3 Monthly flow volumes (x 106 m

3) for Newlands K6H019A01 gauging station

for 1997 to present (# indicates incomplete data set).

Year Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Total

97/98 # 2.49 2.43 4.82 1.48 9.4 4.48 5.77 2.11 3.67 12.3 5.66 #

98/99 7.15 7.49 15.7 9.16 8.94 7.64 6.76 2.56 1.7 3.24 2.82 4.29 77.4

99/00 11.6 2.07 1.88 8.02 5.78 20.9 8.42 2.31 1.77 1.43 1.16 2.02 67.3

00/01 3.69 12.7 1.95 19.6 4.44 4.86 9.23 2.15 1.49 2.74 3.88 4.39 71.1

01/02 6.7 6.04 5.87 2.82 2.55 1.38 1.07 1.69 2.3 10.3 9.24 35 85

02/03 2.71 5.74 5.65 2.98 3.75 29 6.75 14.3 11.2 4.57 3.25 3.95 93.9

03/04 4.24 3.48 2.83 3.39 5.64 8.62 2.5 2.09 2.51 1.9 3.77 12.6 53.5

04/05 12.2 1.56 18 14 4.46 6.1 12.2 2.43 2.26 1.54 0.99 1.14 76.9

05/06 1.13 6.33 2.72 7.29 1.9 6.21 6.47 21.8 5.52 3.88 63.4 9.69 136

06/07 7.9 5.14 9.58 4 2.95 15.9 2.67 10.4 2.71 4.27 4.23 2.6 72.4

07/08 10.2 15.7 39 22.3 10.6 6.87 3.54 2.56 2.71 2.43 3.27 2 121

08'09 17.2 10.3 1.1 0.42 0 0.42 1.72 1.26 2.91 4.51 1.65 2.02 43.5

09/10 3.54 1.18 2.18 1.39 # # # # # # # # #

Max. 17.2 15.7 39 22.3 10.6 29 12.2 21.8 11.2 10.3 63.4 35 136

Min. 1.13 1.18 1.1 0.42 0 0.42 1.07 1.26 1.49 1.43 0.99 1.14 43.5

Ave. 7.36 6.17 8.38 7.71 4.37 9.78 5.48 5.78 3.27 3.71 9.16 7.11 81.64

Month



58

Table 6.4 summarizes the various measured and/or predicted MAR values estimated by

various authors. See Section 6.8.3 for the final flow figures used during the Rapid

Reserve study of 2007.

Table 6.4 MAR values for the Keurbooms and Bitou rivers (after Bornman and Adams

2005).

Reference Keurbooms

X 106m

3

Bitou

x

106m

3

Total

x 106m

3

Midgley and Pitman (1969) 127 32 159

Noble and Hemens (1978) 160

Reddering (1981) > 72.9

DWAF 1978 (In Duvenhage and Morant, 1984) 64

DWAF 1981 (In Duvenhage and Morant, 1984) 71

Ninham Shand (1999; 2003) 154 33 187 (at mouth)

Instream Flow Requirements (IFR), i.e. the flow portion of the Ecological Reserve (or

Ecological Water Requirements), for the Keurbooms Estuary were estimated at

approximately 144 x 106 m

3 per annum or 77% of the present day MAR estimated in

1999 at the estuary (Luger 1999). A conservative approach was followed due to the

paucity of information, with results indicating that the estuary required 100% of present

day flows (or baseflows reaching the estuary). These figures were updated during the

Rapid Reserve study of 2007 (Bitou Municipality 2008) - see Section 6.8.3.

6.7 WATER QUALITY

Figures below indicate nutrient levels for the Keurbooms River and Estuary respectively

(Duvenhage and Morant 1984). The Keurbooms Estuary is considered oligotrophic,

meaning that increases in nutrients (i.e. organic materials) could have negative effects on

the biogeochemistry of the system.

River

Nitrate and Nitrite: 0 – 0.48 mg/L

Ammonia: 0 – 0.71 mg/L

Inorganic orthophosphate: 0 – 0.16 mg/L

Estuary

Nitrate: 3.5 – 4.5 mg/L

Inorganic orthophosphate: 0 – 0.9 mg/L

High nutrient levels in the estuary have been attributed to the release of sewage into the

Bitou Estuary via the Gans Spruit into the Gansvlei (Duvenhage and Morant 1984),

which increases the flux of nutrient into the system. Snow (2005; unpublished data cited

in Bornman and Adams 2005) observed the following nutrient levels in the Keurbooms

Estuary during a minor flood in 2002: Total Organic Nitrogen ranged from 23.17 µM in



59

the upper reaches to 3.58 µM in the lower reaches; PO4 ranged from 1.96 µM in the

upper reaches to 2.55 at the confluence with the Bitou; No detectable concentrations of

NH4 was found in the estuary; Silicate ranged from 35.02 in the upper reaches to 81.3 at

the confluence of the Bitou.

Note that as the town and hence the demand for water grows, so will the volume of

sewage that needs to be discharged. However, most of the treated sewage is currently

used to irrigate existing golf courses and polo fields (Bornman and Adams 2005).

Copper, zinc, iron, manganese, cobalt, nickel and mercury in the surface water showed

average values for Eastern Cape rivers (Watling and Watling, 1980), with the

concentrations of metals in the sediment and water column in the Keurbooms River and

estuary being lower than those observed for the Bitou River. This was attributed the

natural mineralization processes known to occur in the Bitou River catchment.


6.8 ECOLOGICAL WATER REQUIREMENTS

6.8.1 BACKGROUND

The information below is modified from a stakeholder newsletter produced for the

Kromme/Seekoei Intermediate Reserve study of 2003-2006 (DWAF 2004), and is

included for clarification purposes (description of terms is provided in the text box).

The NWA (Chapter 3, Part 3) provides for the protection of significant water resources

through the Reserve. As the DWA is the custodian of the nation’s water resources, it is

the Department’s responsibility to ensure the adequate protection, effective management

and sustainable utilisation of these resources. The Resources Directed Measures (RDM)

Directorate is the Chief Directorate within DWA tasked with the responsibility of

ensuring that Reserve requirements, which have priority over other uses in terms of the

Act, are determined before licensing applications can be processed, particularly in

water-stressed catchments. Reserve determinations can be conducted at a Desktop, Rapid,

Intermediate or Comprehensive level. Each level of determination entails a more detailed

(higher confidence) investigation than the previous level. These determinations have to

take place before the water allocation process (compulsory licensing) can proceed.

Once Reserve requirements are available, the allocable resource could be determined and

water use applications evaluated.



60

This means that human (Basic Human Needs Reserve) and ecological requirements

(Ecological Water Requirements, EWR, or the Ecological Reserve) need to be met before

flow can be harnessed for other users. These requirements are set and have to be

maintained at points along the rivers, streams and estuary. Points are selected via a

rigorous process as they must be representative of stretches of river, and are called EWR

sites. Flow, quality and biotic health objectives are set for these points. Future monitoring

is then conducted against these objectives to ensure that Reserve requirements are being

met.

One of the first steps of the Ecological Reserve process is EcoClassification, or

Ecological Classification. This step refers to the determination and categorization of the

Present Ecological State (PES) of various biophysical attributes (i.e. drivers such as

hydrology, water quality and geomorphology; biotic responses such as fish and

macroinvertebrates; and riparian vegetation) relative to the natural unimpacted reference

condition (Kleynhans and Louw 2007). Once the PES of these variables has been

determined, the EcoStatus, or integrated ecological state is assigned according to the

classification shown in Table 6.5. A description of each A-F category is shown in Table

6.6. The Recommended Ecological Category (REC) is the output of the EWR process.

Reserve: The quantity and quality of water needed to sustain basic

human needs and ecosystems (e.g. estuaries, rivers, lakes,

groundwater and wetlands) to ensure ecologically sustainable

development and utilisation of a water resource. The

Ecological Reserve pertains specifically to aquatic ecosystems.

Reserve requirements: The quality, quantity and reliability of water

needed to satisfy the requirements of basic human needs and

the Ecological Reserve.

Ecological Reserve determination study: The study undertaken to

determine Ecological Reserve requirements.

Licensing applications: Water users are required (by legislation) to

apply for licenses prior to extracting water resources from a

water catchment.

Catchment: The area in which all water ultimately flows into the

same river.

Ecological Water Requirements: This is the quality and quantity of

water flowing through a natural stream course that is needed to

sustain in-stream functions and ecosystem integrity at an

acceptable level as determined during a EWR study.

Water allocation process (compulsory licensing): This is a

process where all existing and new water users are requested to

reapply for their licenses, particularly in stressed catchments

where there is an over-allocation of water or an inequitable

distribution of entitlements.



61

Table 6.5 Generic ecological categories for EcoStatus components (DWAF 2008;

modified from Kleynhans et al. 2005).

Table 6.6 Generic ecological categories for EcoStatus components (Kleynhans et al.

2005).

ECOLOGICAL

CATEGORY DESCRIPTION

A

Unmodified, natural.

B

Largely natural with few modifications. A small change in

natural habitats and biota may have taken place but the

ecosystem functions are essentially unchanged.

C

Moderately modified. Loss and change of natural habitat and

biota have occurred, but the basic ecosystem functions are still

predominantly unchanged.

D

Largely modified. A large loss of natural habitat, biota and basic

ecosystem functions has occurred.

E

Seriously modified. The loss of natural habitat, biota and basic

ecosystem functions is extensive.

F

Critically / Extremely modified. Modifications have reached a

critical level and the system has been modified completely with

an almost complete loss of natural habitat and biota. In the worst

instances the basic ecosystem functions have been destroyed and

the changes are irreversible.

DEVI ATION FROM

REFERENCE CONDITIONSA- F CATEGORIES SCORE

A ? 92.01

A/B >87 .4 and <92.01

B 8 2.01 – 87 .4

B/C >77 .4 and <82.01

C 6 2.01 – 77 .4

C/D >57 .4 and <62.01

D 4 2.01 – 57 .4

D/E >37 .4 and <42.01

E 2 2.01 – 37 .4

E/F >17 .4 and <22.01Serious change

No cha nge

Small change

Moderate change

Large change



62

6.8.2 KEURBOOMS RIVER RESERVE ASSESSMENTS

The RDM surface water database of January 2009, and the Reserve tracking system of

August 2009, was used to identify where Reserve data are available for the Keurbooms

system, i.e. WMA16.

Note the following conditions concerning the use of these databases.

• The database is continuously updated, and only accounts for the Reserves that have

been determined up to the dates indicated, but an attempt has been made to access the

most recent information.

• The database, and associated Reserve templates, is prepared in response to Water Use

License Applications (WULA). Reserve templates are therefore relevant only to the

water use for which the Reserve was requested. New applications would therefore

require an assessment of currently determined Reserves, or re-calculation of the

Reserve.

• The database is specifically concerned with surface waters.

Information on the Keurbooms/Bitou quaternary catchments where Reserve

determinations have been conducted at any level of confidence, are shown in Appendix

II, and include assessments for K60C, D, E (all the Keurbooms River) and F (Bitou

River).

6.8.3 KEURBOOMS ESTUARY RESERVE ASSESSMENT

A Rapid (desktop) Reserve determination was conducted for the Keurbooms Estuary

(K60E/F/G), consisting of the Keurbooms and Bitou river arms, in 2007 (Bitou

Municipality 2008). The Reserve was commissioned by the Bitou Municipality out of

concern for the integrity of the Keurbooms and Bitou Estuaries as various Water Use

Licence Applications (WULAs) have been approved in the K60 tertiary catchment, which

concern some of the rivers that feed into the estuaries (Reserve Draft Template, April

2010).

The geographical boundaries of the estuary were defined as follows for the purposes of

the Reserve study (Figure 6.4):

• Downstream boundary: Estuary mouth (34° 2'31.99"S, 23°23'2.53"E) (This is a

relative position as the Keurbooms The shallow estuary mouth is highly mobile and

regularly changes position along the sand berm at the mouth);

• Upstream boundary – Keurbooms arm: Approximately 12.5 km upstream of the

mouth (33°57'8.04"S, 23°24'6.51"E);

• Upstream boundary – Bitou arm: Approximately 12.8 km upstream of the mouth

(33°59'58.44"S, 23°20'27.49"E); and



63

• Lateral boundaries: 5 m contour above mean sea level along the banks, a delineation

that could be readily referenced from an ortho-photograph of the area.

Map source: Google Earth, 2006

Figure 6.4 Extent of the Keurbooms and Bitou Estuaries as used for the Reserve

determination study – 5 m contour line not shown (Bitou Municipality 2008).

Note that the Rapid Reserve study relied on existing data and no new data were collected.

The accuracy of the study depends largely on the accuracy of the simulated runoff data

and measured flow data. River flow data from the Keurbooms River were available from

November 1997. The overall confidence in the hydrological data provided to the

estuarine team by Ninham Shand Consulting Services was considered to be Medium

(Bitou Municipality 2008).

The Estuarine Health Index (EHI) score for the estuary indicated that the estuary’s

(Keurbooms/Bitou) Present Ecological State is in an A/B Category. In terms of the

importance the estuary was signified as a highly important estuary and is listed as a

Desired Protected Area in the C.A.P.E. Estuaries Conservation Plan for the temperate

areas of South Africa (Turpie and Clark 2007), and thus should be managed for Category

A or Best Attainable State (BAS). However, the system cannot be rehabilitated to a

Category A due to the pressures contributing to the present state of the estuary. Thus,

Category A/B was considered the BAS or the Recommended Ecological Category (REC).

An A/B category represents a largely natural state (see Tables 6.5 and 6.6).

The quantification of Ecological Reserve Scenarios was undertaken as part of the Reserve

assessment – results are shown in Table 6.7 (Bitou Municipality 2008; Reserve Template



64

2010). The evaluation of the simulated runoff scenarios was used to derive the REC. The

REC was defined as the runoff scenario (or a slight modification thereof) that represents

the highest reduction in river inflow that will still protect the aquatic ecosystem of the

estuary and keep it in the required category. In evaluating Future Scenarios 1 to 4 it was

assumed that only river inflow from the Keurbooms catchment will be reduced and that

all other related anthropogenic activities (e.g. fishing, bait collection, power boating and

human disturbance) will remain at present levels. Taking the above into account,

Scenario 1 was selected as the REC for the Keurbooms Estuary as this scenario will

maintain the estuary in an A/B category with less impact on the environment (with only 8

% of the MAR reduced from reference state), while allowing some use of the estuary.

Table 6.7 A summary of the mean annual runoffs (MAR) of the various Simulated

Monthly Runoff Scenarios used for this Rapid level determination with the PES under

each scenario.

The estuarine specialists who were a part of the Reserve study team also concluded that

Future Scenario 2 probably does not pose a serious risk to the health of the

Keurbooms/Bitou Estuaries, but that more data will be required over the next few years to

increase the overall confidence in the study. This includes additional data on mouth and

sediment dynamics, water quality and invertebrates. Such data will improve the estuarine

specialists’ overall understanding of the system’s response to flow reduction.

6.8.4 PRELIMINARY RESERVE TEMPLATE (APRIL 2010)

The draft Preliminary Reserve template (see below) was obtained from Chief Directorate:

Resource Directed Measures (CD: RDM) at DWA in April 2010, and conditions and

background are shown below. Note that upon completion, these values will be signed by

the Chief Director of the CD: RDM, and Gazetted for implementation to manage the

Na me De scription

Keurbooms

MAR

(MCM/a)

Bitou

MAR

(MCM/a)

Combine d

MAR

(MCM /a)

% natural

M AR PES

Re ference Reference Con dition 174 58 232 100% A

PresentPresent State, including a diversion of 0. 1 m

3/s

to Pletten berg Bay164 51 215 92.70% A/B

Future

Scenario 1

As at Present State but the diversion is

increased to 0.45 m3

/s , no off-channel

s tora ge, 0. 145 m3

/s to Roode fontein,

include Rive r EWR

1 63 5 1 214 92. 20% A/ B

Future

Scenario 2


increase d to 0.45 m3/s with off-ch annel

storage, 0.29 m3/s to Roo defontein, inclu de

River EW R

157 51 208 89.70% A/B

Future

Scenario 3


increased to 0.65 m 3/ s a bst raction

(unconstrained), include River EWR

148 51 199 85.80% B

Future

Scenario 4


increased to 1 .0 m3/s (u ncon strained), include

River EW R

140 51 191 82.30% B



65

Keurbooms and Bitou Estuaries. Note that due to the low confidence of the extrapolated

results of this preliminary determination of the Reserve, the results should not be used to

evaluate high impact water use activities.

*Keurbooms Estuary includes both the Keurbooms and Bitou systems.

The objectives of the CD: RDM are to at least maintain, and if possible to improve

the PES of the estuary. The following conditions have been incorporated into the

letter to the region from CD: RDM, based on the result of the Keurbooms Estuary

Reserve study. Text is taken directly from the letter to the region (received from Jafta,

CD: RDM, April 2010).

To meet the EWR, there had to be some assumptions and limitations on the hydrology.

There was an agreed interim requirement that the diversions be reduced or stopped when

the river flow decreases below 0.3 m3/s and the diversion capacities were reduced by a

22/24 hour factor to account for breakdowns or power supply. It was also proposed that

the river inflow to the Bitou Arm of the Keurbooms system should remain similar to the

present state because: the Bitou Arm comprises an important, ecologically sensitive

wetland; the baseflows from the Bitou River are very low and it would be very easy to

remove all flows to the Bitou Arm of the estuary; the upper part of the Bitou Arm is very

narrow and shallow and potentially very sensitive to changes in flows; and due to the

absence of data (i.e. only one hydrographical station located in the lower part of the Bitou

Arm) no recommendations could be made regarding future abstraction from the Bitou

catchment.

6.8.5 NON-FLOW RELATED CONSIDERATIONS

The present ecological functioning of the Keurbooms Estuary is influenced by a number

of anthropogenic non-flow related issues. The correct management of these issues has the

potential, in conjunction with managing flows, to improve the ecological functioning of

the system and therefore the goods and services they provide. The following

recommendations should be considered.

Since the Keurbooms Estuary is a highly important system from both a socio-economic

and ecological perspective it is recommended that a project be initiated whereby the loss

in water column habitat (that would be incurred under Scenario 1) be mitigated for by

restoring some of the intertidal habitat and wetland vegetation to more natural conditions

where possible, as proposed in the Keurbooms/Bitou Estuarine Wetland Assessment

(Bornman and Adams 2006).

If the scenario recommended by the rapid reserve determination study were to be

implemented, it was recommended that the following mitigation measures be investigated

Water

re sourceW MA

Quaternary

catchmentPES EIS R EC

vMAR

(MCM)

Reserve (% of

vM AR)

Level of Reserve

Dete rmination

Keurbooms

Estua ryGo uritz K60E/F A/B High A/B 232 92.2 Rapid



66

(with full stakeholder participation) and incorporated in the license agreement between

the Bitou Municipality and DWA (Bornman and Adams 2006):

12. Bitou Drift: The drift through the Bitou River should be removed in total including all

foreign rock material.

13. Northern floodplain of the lower Bitou Estuary: Remove all exotic invasive trees from

the flood plain. No further development should be allowed on the floodplain to

prevent further loss of floodplain functionality. Remove the old gravel road to the

south of the R340.

14. Southern floodplain of the lower Bitou Estuary: Remove all exotic invasive plant

species from the floodplain, remove the infilling, create a buffer zone (~ 10 m wide

separating the wetland from the agricultural activities on the floodplain).

15. Road Bridge across the lower Bitou Estuary: Remove concrete piers of the old road

bridge to facilitate flow and tidal exchange in the Bitou Estuary and establish

connection with old Bitou channel.

16. Middle reaches of the Keurbooms Estuary: Remove all alien trees from the banks and

The Island. Establish a buffer adjacent to the estuary and restrict new development on

the banks of the estuary.

17. Upper reaches of the Ganse Spruit: Remove all exotic vegetation from the stream

bed.

18. The Ganse Spruit Wetlands: Install a sufficient number of large culverts in the

roads bisecting the wetlands to allow the free flow of surface water through the

wetlands and remove all exotic invasive tree species.

19. Earthen barricades across tidal channels in the Bitou Arm: Completely remove all

earthen barricades to restore connectivity on the supratidal marsh. Maintain

freshwater flow from northern sections into the supratidal marsh south of the R340.

20. Middle reaches of the Bitou Estuary: Remove all exotic tree species from this area,

allow the artificial canal to naturally silt up, allow salt marsh to naturally re-colonise

the extensive Stenotaphrum grasslands, insert culverts below the road bisecting the

floodplain to link up the old channels.

21. Old Cape Road canal: Increase the width and depth of the canal dug through the old

Cape Road embankment (to the south of the old Cape Road pillars in the water).

Increasing the size of that canal will facilitate flushing of the Bitou (cut out the S

bend).

22. Development of an Estuary Management Plan: It is also recommended that an

Estuary Management Plan (EMP) be developed for the Keurbooms Estuary (includes

Bitou Estuary) following the guidelines developed for the estuaries of the Cape Floral

Region. The development of an EMP would provide a framework for evaluating the

proposed mitigation measures for improving the health of the estuary and the

feasibility of their achievement. The management plan would also assist in allocating

roles and responsibilities to all authorities managing activities in and around the

system, as the current impacts on the estuary are managed by various spheres of

government ranging from the local (e.g. development) to the national (e.g. fishing)

level.



67

It is essential that the non-flow related recommendations given in the Reserve

Determination reports be captured, together with these flow objectives, in the water

resource protection sub-strategy of the catchment management strategy for this

catchment. This management plan should also address the freshwater biodiversity needs

of the catchment, where the specific flow, water quality habitat and biota objectives

necessary to meet the biodiversity targets are included. Issues should be given serious

consideration, particularly in terms of developing an EMP and improving the poor

condition of the vegetation communities (e.g. supratidal saltmarsh).

6.9 SOCIO-CULTURAL IMPORTANCE

Although the Keurbooms and Bitou Estuaries are of significant value to local inhabitants

with regard resource use and recreational pursuits, no information is presently available

on the socio-cultural importance of the freshwater systems, other than the rivers being an

important source of agricultural and domestic water supply for the region.

6.10 PRESSURES/RISKS/THREATS

Pressures currently contributing to the present state of the Keurbooms and Bitou

Estuaries, in terms of water quantity and quality issues are fishing and bait collecting

activities, human disturbance in and around the estuary (wastewater discharge;

recreational activities), structures in the intertidal and supratidal (floodplain) area and

flow reduction from the Keurbooms and Bitou catchments (abstraction and

impoundments/damsBitou Municipality 2008). Some detail is provided below:

• Reduction in river floods: As the discharge rate and frequency of river floods

become less, the erosional capacity of floods decreases, allowing unnatural sediment

build-up and impacting on habitats.

• Structures: Weirs, bridges and causeways acts as obstructions to water flow, e.g. the

N2 bridge has resulted in disturbances to large salt marsh areas.

• Wastewater discharges, e.g. dump sites, stormwater, sewage discharges: Increased development results in increased wastewaters and sewage discharges

potentially impacting on aquatic systems.

• Human exploitation, e.g. bait collection, boating, angling, floodplain developments. All the above activities may lead to potential pollution, habitat

destruction and bank erosion, including the invasion of alien tress onto floodplain

areas and reed encroachment.

• Poor land use practices in the upper catchment: Poor land management results in

increased sediment input, nutrient enrichment and pollution.

• Uncontrolled water abstraction and impoundments: Poorly managed upstream

impoundments result in altered flow regimes reaching estuaries, i.e. reduced base flow

required for ecological functioning and insufficient freshwater pulses for scouring and

mouth maintenance.



68

CHAPTER 7 - CLASSIFICATION, ECONOMIC VALUE,

PROTECTION AND REHABILITATION

7.1 CLASSIFICATION13

Harrison et al. (2000) class the Keurbooms as a warm-temperate, permanently open,

medium-large, Type F barred system (supratidal barrier), whose ichthyofauna, water

quality and aesthetics are rated as good, good and moderate respectively. Overall

condition was rated as Good by Whitfield (2000) although he does remark that any major

dams in the catchment could severely impact on this status.

A recent study by Turpie and Clark (2007) ranked the Keurbooms as the 18th

most

important estuary in South Africa in terms of biodiversity with an overall importance

score of 88 out of a possible 100. This ranking was based on a detailed assessment of

both ichthy- and avifauna. They also ascribe an A/B management class to the system

based on the freshwater requirements. The Rapid Ecological Reserve Determination

(Bitou Municipality 2008) for the Keurbooms confirmed this A/B status based on an

Estuarine Health Index score of 90, which comprises a habitat health score of 94 and a

biotic health score of 87. An index score of A represents an unmodified, natural system,

while B represents a system that is largely natural with few modifications. In order to

maintain the system in the A/B class, the Rapid Reserve Determination study

recommends a scenario where abstraction or diversion of freshwater (to Plettenberg Bay)

can be increased to 0.3 m3/s from the present diversion of 0.1 m

3/s.

Coetzee et al. (1997) applied a botanical rating system to estuaries, which allowed each

system to be scored according to area covered by each plant community type, its

association with the estuary, its condition and the plant community richness (number of

species). Thirty-three estuaries were evaluated between the Olifants in the Western Cape

and the Great Kei in the Eastern Cape and the plant community types considered were

supratidal saltmarsh, intertidal saltmarsh, submerged macrophyte beds and reeds and

sedges (reedswamp). The Keurbooms Estuary was rated tied 8th

overall (5th

amongst

permanently open systems) together with the Gamtoos and Wildevoelvlei systems with a

rating score of 250 (normalised score of 61 out of 100); the top-rated estuary overall was

the Olifants with a score of 410 (normalised score of 100). Within the Southern Cape

region, the Keurbooms was rated 2nd

out of six systems with a score of 250 – Groot Brak

is rated first with a score of 290. Of the four plant community types used in the rating

system, submerged macrophytes were most important (80), followed by intertidal

saltmarsh (70), reedswamp (60) and supratidal saltmarsh (40). This rating system can be

slightly misleading as the score and ranking does not necessarily reflect the overall health

of a system but merely the state of the botanical community. It does, however provide an

indication of which estuaries should be accorded a high conservation status and be

allocated sufficient freshwater in order to maintain it present state.

13

Note that the Keurbooms refers to both the Keurbooms and Bitou Estuaries as well as the Keurbooms

lagoon.



69

A modification of the botanical rating system that took functional importance, species

richness, plant community type richness and plant community type rarity into account

(Colloty et al 2001) resulted in the Keurbooms system being ranked 27th

out of 30 warm-

temperate estuaries, with a rating of 235. The top ranked warm-temperate estuary is

Knysna with a rating of 360. The Keurbooms system does not rank in the top 36 estuaries

in the country in terms of botanical importance (St Lucia is ranked No. 1).

7.2 ECONOMIC VALUE

Turpie and Clark (2007) placed the following economic values on the Keurbooms

Estuary:

Subsistence - ranked 7th

amongst temperate systems with a value of R379 006 per

annum; top ranked system is the Swartkops with a value of R808 953.

Property – ranked 10th

amongst temperate systems in terms of property value related to

estuaries with a value of R399 million; top rated is Knysna with a value of R1.4 billion;

range of property value related to all temperate estuaries is between R1 million and R2

billion; most systems fall into the R10 – 50 million range.

Tourism – ranked 2nd

amongst temperate systems in terms of tourism value attributed to

estuaries with a value of R400 million per year; top ranked is Knysna at R1 billion; total

value for all temperate systems is R2.08 billion; most are between R10 000 and R1

million although 23 estuaries have an estimated tourism value of < R10 000.

Nursery (protection of juvenile organisms) – ranked 11h amongst temperate systems

with a value of R13.8 million per annum; top value is Knysna at R167.6 million.

Existence – the Keurbooms does not rank amongst the top 40 temperate estuaries; overall

the public’s willingness to pay (WTP) for estuary conservation in SA for all income

groups is valued at R80 842 180.

7.3 PROTECTED AREA STRATEGY AND POTENTIAL

7.3.1 ESTUARY PROTECTED AREAS

The establishment of a core Estuary Protected Area (EPA) network around the South

African coastline should take into account the following goals (after Turpie and Clark

2007):

• Representativeness: all estuarine species within a bioregion should be represented in

viable numbers in the protected areas network.

• Maintenance of ecological processes: the protected area network should allow for

connectivity and interaction with other adjoining ecosystems.

• Maintenance of fishery stocks: the protected area network should provide enough

protection to exploited species that they are able to act as source areas for surrounding

exploited areas.

• Minimization of economic opportunity costs: biodiversity targets should be met at

least possible opportunity cost, through careful selection of the estuaries included in



70

the protected area network. Estuaries where protection offers greatest economic

benefits or lowest economic costs should be prioritized in the EPA selection process.

• Implementabilty: consideration should be given to the practicalities of protection in

each estuary.

The biodiversity protection targets addressed in Sections 7.3.2 to 7.3.4 below address the

first three goals listed above. The final choice of estuaries that will be used as part of an

EPA network that will realize these targets will be subject to the final two goals listed

above.

7.3.2 PROTECTION OF HABITAT TYPES

Targets for the protection of estuarine habitat types (as a percentage of the total estuarine

habitat measured in hectares) have been recommended by Turpie and Clark (2007). The

percentages for habitat types found in the Keurbooms are as follows; supratidal salt

marsh (30%); intertidal salt marsh (40%); reeds and sedges (20%); sand/mud banks

(40%); submerged macrophytes (40%); and estuary channel (30%). The overall

percentage of all habitat types combined that should be protected is 30% of the total

available 25 095 hectares.

7.3.3 PROTECTION OF FISH AND BIRD SPECIES

Similarly targets for the protection of fish and bird species (as a percentage of the total

population) were set at 50% of the population of red data (threatened) species; 40% of the

population of exploited species; and 30% of the population of all other species. The

effective targets for selected individual species that are associated with the Keurbooms

are provided in Table 7.1 (after Turpie and Clark 2007). Amongst the bird species it is

only the African black oystercatcher that is a listed threatened species with the remaining

assemblage falling under the 30% protection target. Amongst the fish it is only the

Knysna seahorse that is endangered, and all fish assumed to feature prominently in

fishermen’s catches, such as dusky kob, spotted grunter, white steenbras and bait species

such as mullet are targeted for 40% protection of the population.



71

Table 7.1 Target percentages for the protection of selected estuarine fish and bird species

(after Turpie and Clark 2007).

7.3.4 PROTECTION OF ECOSYSTEM AND LANDSCAPE-LEVEL PROCESSES

The protection of habitat types and associated fauna in estuaries may only be considered

effective if the populations benefiting from these measures are viable, that is to say that

they are sufficiently large and there is a degree of overlap between protected

areas/populations to ensure the maintenance of genetic integrity and evolutionary

processes. In order to achieve this, Turpie and Clark (2007) recommended the following

measures which would also serve to help maintain landscape-level processes that

maintain ecological integrity at a large scale (relevance to the Keurbooms estuary is also

provided:

• Viability: EPAs should protect a minimum of 33% of each habitat within an estuary

as a no take sanctuary. Although this may not be a realistic measure it is potentially

attainable due to the large size of the estuary and extent of individual habitats.

FISH SPECIES TARGET % BIRD SPECIES TARGET %

Acanthopagrus berda 30 White-breasted Cormorant 30

Anguilla mossambica 30 African Black Oystercatcher 50

Argyrosomus japonicus 40 Common Ringed Plover 30

Atherina breviceps 30 White-fronted Plover 30

Caffrogobius gilchristi 30 Grey Plover 30

Caffrogobius nudiceps 30 Terek Sandpiper 30

Diplodus sargus capensis 40 Common Sandpiper 30

Elops machnata 40 Curlew Sandpiper 30

Galeichthys feliceps 40 Common Greenshank 30

Gilchristella aestuaria 30 Red Knot 30

Heteromycteris capensis 30 Little Stint 30

Hippocampus capensis 50 Sanderling 30

Lichia amia 40 Bar-tailed Godwit 30

Lithognathus lithognathus 40 Eurasian Curlew 30

Liza dumerilii 40 Common Whimbrel 30

Liza richardsonii 40 Pied Avocet 30

Liza tricuspidens 40 Black-winged Stilt 30

Monodactylus falciformis 30 Kelp Gull 30

Mugil cephalus 40 Caspian Tern 30

Myxus capensis 40 Swift Tern 30

Pomadasys commersonnii 40 Sandwich Tern 30

Pomatomus saltatrix 40 Common Tern 30

Psammogobius knysnaensis 30 Little Tern 30

Rhabdosargus holubi 40

Sarpa salpa 40

Solea bleekeri 30

Syngnathus temminckii 30

Torpedo sinuspersici 30



72

• Viability: Systems in an unacceptable state of health should be excluded, particularly

canalized systems. The Keurbooms is in a fair state of health according to Whitfield

(2000) and enjoys a high biodiversity importance rating of 92, placing it in 11th

position amongst the country’s estuaries.

• Connectivity: There should be a relatively even distribution of protected estuarine

area around the coast. A network of EPAs has yet to be set up and it is not known

how the Keurbooms would feature in this arrangement.

• Landscape level processes: Estuaries adjoining terrestrial or marine protected areas

will be prioritized in the selection process, and those adjoining undeveloped land

should be prioritized over those that are developed. There is not much undeveloped

land in the lower and middle reaches of the estuaries although the upper reaches

represent relatively pristine areas.

• Viability, ecosystem processes, evolutionary processes and representativeness: Large

open systems should be prioritized over smaller systems but a range of different sized

estuaries should nevertheless be represented. The Keurbooms is a medium/large open

system.

• Efficiency: Systems with higher conservation importance scores should be given

greater priority. The Keurbooms has a high score (92) in this regard.

7.3.5 TYPE OR LEVEL OF PROTECTION

The study by Turpie and Clark (2007) concluded that in order for conservation targets

and goals to be achieved, 80% of temperate estuaries needed some form of partial

protection rather than a few with total protection; in many instances this was because the

benefits of partial protection were seen to outweigh the management and opportunity

costs. Furthermore it became apparent that a greater level of protection of estuaries would

be desirable from a socio-economic perspective than would be necessary just in order to

meet biodiversity conservation targets. The partial protection of 80% of estuaries was

also deemed desirable from a management perspective, in that it would facilitate the

introduction of an almost universal sanctuary zone in each estuary, which is marked by

standard markers, which in turn would facilitate public awareness about the estuarine

protection system.

Initial guidelines for the conservation of estuarine biodiversity (Turpie 2004) required

that estuaries be assigned to one of three categories, namely:

• Estuary Protected Areas (EPAs) - part or all of an estuary is a sanctuary, providing

protection from consumptive use; state-run; selected with both biodiversity

representation and socio-economic considerations in mind;

• Estuary Conservation Areas (ECAs) - co-managed estuaries in which general

regulations are augmented by estuary-specific regulations; initiated by local

communities through estuary forums which would also design zonation schemes and

bylaws; likened to the role of private nature reserves and conservancies in the

protection of terrestrial biodiversity, and are generally not considered to contribute to

protected area conservation targets because their contribution to conservation is less

secure in the long term; and



73

• Estuary Management Areas (EMAs) - to which general regulations apply; at least

must have a management plan in order to facilitate compliance with general

regulation and maintain estuarine health at an acceptable level.

However, due to complications that arise between fully and partially protected systems

with respect to national legislation and the subsequent administration of EPAs and ECAs

it has been recommended that the above categories be scrapped and that zonation be used

instead as a general strategy in the management of estuaries (Turpie and Clark 2007).

Essentially this means that the estuaries selected to form part of an overall protection

network should contain a sanctuary zone and should receive sufficient protection and

sufficient quantity and quality of freshwater inflows to be maintained in an appropriate

state of health.

The zonation strategy means that individual estuaries may contain a fully protected

(sanctuary) area, which would include terrestrial margins, and a conservation area that

would be zoned according to the vision and objectives/requirements for that estuary.

Sanctuary areas would fulfill the same function as an EPA and as such would have to be

set up and managed by an organ of the state. Conservation areas may be managed by a

wide variety of styles within a co-management setup where the community and an

estuary management forum are the main role players. By adopting a system like this on

all selected estuaries, it is likely to be easier and more efficient to manage the entire

network, especially if similar rules apply and similar markers and mapping styles are

used in all estuaries to denote sanctuaries and other types of use zones (Turpie and Clark

2007).

7.3.6 THE KEURBOOMS IN PERSPECTIVE

Based on the findings of Turpie and Clark (2007), the following can be said about the

Keurbooms/Bitou estuaries with regards to requirements in terms of protection:

• The Keurbooms is one of the core set of temperate estuaries required to meet the

targets for biodiversity protection of estuarine resources; scores (out of 100) that

contributed to the overall rating of 88 for the Keurbooms were size (100), habitat

importance (90), zonal type rarity (20) and biodiversity importance (95).

• Targets for the protection of habitat types (as a percentage of the total estuarine

habitat measured in hectares) are as follows; supratidal salt marsh (30%); intertidal

salt marsh (40%); reeds and sedges (20%); sand/mud banks (40%); submerged

macrophytes (40%); and estuary channel (30%). The overall percentage of all habitat

types combined that should be protected is 30% of the total available 25 095 hectares.

• The recommended extent of undeveloped margin is 50% (an average score for public

perception of optimal level of development around SA estuaries was 40%).

• The recommended minimum water requirement falls under the A/B management

class, which means a high priority and requirement and the priority for rehabilitation

is HIGH.



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7.4 RESTORATION/REHABILITATION

A workshop attended by estuarine scientists and managers was held to determine which

temperate estuaries should be prioritized for rehabilitation (see Turpie and Clark 2007)

and which issues should be addressed in each estuary. A total of 50% of temperate

estuaries were considered to be in need of some form of rehabilitation; these included

systems ranging from a poor to excellent state of health. Thirty-nine estuaries, including

the Keurbooms, were given a HIGH priority status for rehabilitation. According to the

consensus opinion at the workshop the single requirement for rehabilitation on the

Keurbooms Estuary is clearing of alien vegetation. Interestingly there is no mention of

restoration of areas that have undergone inappropriate bank stabilization, but the report

pre-dates the 2007 floods that caused extensive damage and resulted in large areas of the

banks in the lower-reaches being stabilized by property owners. There is also no mention

of the rehabilitation of the Bitou wetlands, which is seen as a priority by this report; this

can be accomplished in cooperation with landowners and Non-Governmental

Organizations (NGOs) such as Working for Wetlands.

7.5 CLIMATE CHANGE

There are several threats associated with climate change that are of particular relevance to

estuaries, their users and the surrounding area (DEADP 2007). These include decreased

rainfall (drought), increased rainfall and frequency of freshwater floods, increased water

temperature (marine/estuary), sea-level rise and increased frequency and intensity of

storm events. These are all relevant to the Keurbooms/Bitou area as drought can affect

farmers and the availability of the ecological reserve, flooding events can be devastating

in the area, increased temperature affects the survival and distribution of species and sea-

level rise and storm events pose a threat to landowners and infrastructure, either on their

own or when occurring together.

Although already referred to in Section 4.4.3, we again stress that the Western Cape

PSDF takes climate change into account and categorically states that:








75

CHAPTER 8 - THE WAY FORWARD: OBJECTIVE II

8.1 LOCAL ESTUARY MANAGEMENT FORUM

Objective II involves the process of formulating an Estuary Management Plan (EMP) for

the Keurbooms and Bitou Estuaries (inclusive of the lagoon area). This will be achieved

through a workshop aimed at obtaining stakeholder input with regards aspects such as the

vision, strategic objectives, management action plans and zonation plan. Ideally the EMP

should be developed with the help of a constituted local management institution, which

represents all the relevant stakeholders and their interests. This management institution

would take the form of an Estuary Management Forum (EMF) and would comprise the

following (van Niekerk and Taljaard 2007):

• A chairperson, to be elected by the forum and to take the lead in the development and

implementation of the local EMP.

• Technical Working Groups for each of the following key result areas:

− Biodiversity conservation;

− Exploitation of living resources;

− Land-use and infrastructure development;

− Water quantity and quality;

− Institutional and management structures

− Tourism;

− Sustainable livelihoods; and

− Education and awareness

• The forum itself comprising all stakeholders.

The Technical Working Groups should ideally include representatives from the

authorities who have a mandate and executive powers within the specific sector (e.g.

conservation; water quality) as well as competent natural or social science specialists

acting in an advisory role. It is likely that CapeNature will be the lead authority.

Because the Keurbooms does not possess a management forum at present, Enviro-Fish

Africa are fulfilling the role of developing and initiating the implementation of the EMP

and will make recommendations that a constituted forum be set up to ensure the long-term

implementation and monitoring of the EMP.

8.2 THE ESTUARY MANAGEMENT PLAN

Key to the formulation of an EMP will be the organization of a stakeholder workshop in

order to develop a vision and objectives for the Keurbooms and Bitou systems based on

the Situation Assessment (this report) and the future needs and desires of the

stakeholders. These outcomes together with the assessment provided by Turpie and Clark

(2007; Chapter 7), the rapid reserve determination study (Bitou Municipality 2008) and



76

the C.A.P.E. Generic Framework for EMPs (van Niekerk and Taljaard 2007) will be used

to formulate the EMP.

Essentially the following tasks will be performed for Objective II:

• Assist in setting a Vision and Strategic Objectives for the Keurbooms and Bitou

Estuaries.

• Develop a range of Management Strategies to achieve the Vision and Objectives.

• Prepare an Estuary Zonation Plan (EZP) and Operational Objectives based on the

above.

• Identify Management Action Plans (MAPs) to achieve all strategies and operational

objectives including implementation procedures (includes human and financial

resources).

• Propose an institutional structure (i.e. the EMF) to guide the implementation of the

EMP.

• Develop a monitoring and evaluation programme including a description of a process

for reviewing the management plans.

• Identify research priorities.

8.3 THE STAKEHOLDER WORKSHOP

The workshop will concentrate on the development of a vision, strategic objectives and

zonation plan and will also need to address the prioritization of issues.

In order to provide stakeholders attending the workshop with some idea of what to

expect, some useful background information is supplied in the sections below.

8.3.1 VISION

The Vision for the estuary should be inspirational, representing a higher-level statement

of strategic intent, while taking into account the Vision set for all estuaries within the

greater Cape Floristic Region.

One should also consider including a reference to the desired Category for the systems as

this will, in most instances, determine the strategic objectives and management actions

required to achieve the Vision. For example, if the Vision contains a reference to

ensuring that the estuaries are maintained at a Category A or B level, this implies that

certain water quality and quantity objectives need to be met.

Vision for Estuaries in the CFR: Our estuaries are beautiful, rich in plants and animals, they

attract visitors, sustain our livelihoods and uplift our spirits



77

8.3.2 STRATEGIC OBJECTIVES

The strategic objectives are generally qualitative statements of the values defined in the

vision and should be statements of outcomes rather than means of achievement. For

example, if the Vision refers to a “beautiful estuary”, then the strategic objectives for the

relevant key result areas need to reflect aspects such as clean water, rehabilitation of

banks and no development within the 1:100-year floodline. For the Keurbooms/Bitou, the

strategic objectives proposed for the larger CFR (see text box below) need to be

considered and can provide inspiration for the setting of estuary specific objectives.

Strategic Objectives for the Estuaries of the CFR include:

Living resources: Achieve targets for ecosystem biodiversity and health in terms of

the long-term habitat persistence of habitats, species, community structure, biomass

and functioning by 2015.

Water quantity and quality: Determine, implement, monitor and review Resource

Quality Objectives (RQOs) (taking into account public health) in order to maintain

or restore estuarine structure and function in the best attainable state for five priority

estuaries within the CFR by 2010.

Land-use and infrastructure planning: Define estuarine areas, assess their current

status and values and formulate appropriate integrated management plans to

regulate development and other activities impacting upon them, with particular

reference to cumulative impacts, by 2008 (focusing on mechanisms).

Institutional and management structures: Cooperatively manage estuaries, through

relevant institutions of management comprising appropriate spheres of government

and civil society, according to appropriate management plans by 2010.

Climate change: Minimise the detrimental impacts of predicted climate change by

2010 through:

1) Taking a long-term precautionary approach to infrastructure development and

water-resource planning;

2) Influencing land management in upper and middle catchments to reduce

impacts on estuaries; and

3) Promoting long-term sustainable livelihoods through estuarine management

that minimises risks.

Education and awareness: Generate education and awareness regarding CFR

estuaries by 2010, having:

1) Contributed to integrated, collaborative and informed action and decision

making regarding estuaries;

2) Contributed to a sustainable quality of life;

3) Promoted good management practices that will sustain healthy estuarine

functioning;

4) Raised awareness of the intrinsic value of estuaries and developed a sense of

ownership of estuaries not only among local communities but throughout South

Africa; and

5) Raised awareness of and insight into the legal context and obligations of all

levels of government (national, provincial, local and community).



78

The developed Vision and Strategic Objectives for the Keurbooms/Bitou may not conflict

with those developed for the CFR. Strategic Objectives for specific systems should be

listed in priority order to guide subsequent management decisions. The Strategic

Objectives must form the foundation for quantitative, operational objectives. Obviously

some of the timeframes listed in the CFR Strategic Objectives have already not been met

and would need to be revised.

8.3.3 MANAGEMENT STRATEGIES

The Vision and Strategic Objectives may be achievable through various management

strategies and these will be investigated and evaluated so as to optimally utilize financial

and human resources. Existing institutional management strategies must be incorporated

where appropriate. Before finalization of an EZP and the development of the operational

objectives, the different management strategies may have to be refined through

collaboration with stakeholders; this will be addressed during the course of the workshop

8.3.4 ZONATION PLANS AND OPERATIONAL OBJECTIVES

Once management strategies have been agreed upon, these will need to be translated into

an EZP and Operational Objectives. The EZP will be in the form of a map that clearly

demarcates the following:

• Geographical boundaries;

• Conservation/Protected zones as well as degree or class of protection needed;

• Zones demarcated for the exploitation of living marine resources (e.g. fishing and bait

collection);

• Important bio-physical features (open channel areas, Macrophyte beds, invertebrate

beds, mud banks, sand banks, wetlands, salt marshes, indigenous vegetation etc);

• Areas earmarked for rehabilitation;

• Land-use and planning provisions of surrounding areas;

• Infrastructure (e.g. roads, bridges);

• Cultural and heritage sites;

• Existing recreational and cultural activities (e.g. swimming, skiing, traditional

ceremonies etc);

• Wastewater discharges (sewage, industrial)

The Operational Objectives and Management Action Plans required to achieve these

objectives will be addressed subsequent to the workshop as will the implementation plan,

monitoring and evaluation programme. A draft EMP report will be circulated to all

stakeholders for comment prior to finalization of the report, which will be presented at

another workshop at the start of the Implementation Phase.



79

8.4 ISSUES RAISED BY STAKEHOLDERS

The following issues were identified during stakeholder meetings. These will be

addressed in the EMP and do not appear in any particular order:

• An improved zonation plan is required (includes indication of floodlines, wake-free

and skiing zones).

• Estuary-specific by-laws are urgently required so that issues such as houseboats and

wake-free zones can be enforced. Speeding boats below the N2 bridges are a threat to

safety and interfere with other recreational activities such as fishing. Area above N2

bridge on Keurbooms is covered by Keurbooms Nature Reserve and enforced by

CapeNature Ordinance.

• Wake-free zones need to be indicated as such and NOT as 10 kph.

• Implementation of the Ecological Reserve.

• Alien vegetation clearing, both in the catchment and within estuary area.

• Contaminated freshwater runoff from farmlands and commercial forestry plantations.

• Conservation of wetlands (includes saltmarsh) associated with both systems.

• Compliance monitoring needs to be improved.

• Water licensing and use (abstraction) needs to conform to Reserve Determination

recommendations.

• Sewage pump stations on eastern side of Keurbooms cannot cope with peak season

loads.

• Incorporation of 1:100-year floodline in zonation to restrict irresponsible

development.

• Consider making the Bird Sanctuary a no-go area to reduce disturbance.

• General monitoring of water quality, particularly at sites where sewage may enter the

system (e.g. Rietvlei and Gansvlei areas).

• A Municipal environmental officer is required.

• More stringent control over bait collecting activities (includes illegal selling).

• The availability of recreational fishing permits over the weekend was viewed as

problematic and could impact on tourism.

• Threatened species such as the Knysna seahorse and pansy shell and their preferred

habitat need to be protected (adjacent to the Keurbooms Lagoon Caravan Park for

pansy shells and in the region of the confluence for the Knysna seahorse).

• Time taken to obtain authorization to carry out rehabilitation after floods is excessive

and leads to illegal activities; process needs to be streamlined and a standardized

approach adopted to cover instances of repeated damage after each flood event.

• No fishing competitions.

• Education and awareness programmes need to be initiated (regulations, importance of

estuaries etc.). Adopt an approach of education before issuing of fines.

• Abandoned hake long-line vessels on the Keurbooms need to be removed (safety and

possible pollution source).

• Impact of a possible desalination plant.

• Reinstate financial assistance from the Municipality to help with CapeNature’s

management actions outside of the Nature Reserve.

• Additional field rangers (two) required so CapeNature can operate effectively.



80

• Investigate feasibility of making funds from boat licenses available for management

actions.

• Compliance of CapeNature personnel with skippers’ license requirements.

• Feasibility and impact of dredging to deal with excessive sediment loads.

• The proposed N2 bypass route through the lower reaches (SANRAL) needs to be

considered.

• Impact of a major dam in the Keurbooms and/or Bitou catchment.

• All management interventions that affect landowners need to be a part of a public

participation process, i.e. cooperative and not prescriptive.

• Feasibility of off-stream storage of excess flood waters to offset shortages during

times of drought.

• Clearing of debris (from alien clearing) in the catchment to reduce damages from

floods.

• Feasibility of landowners undertaking alien clearing (using own labour) as long as

funding is made available.

• Clearly indicate which government departments are responsible (mandated) for which

management interventions.

• Need to highlight the Keurbooms as a unique tourist attraction (e.g. same as

Robberg).

• Investigate additional activities that can add to attraction of the Keurbooms as a

tourist destination (e.g. hiking trails and sporting events).

• Bank erosion, from clearing of aliens, is an issue in the upper Keurbooms catchment.

• Capacity of Bitou sewerage treatment works to cope with increased development.

• Government involvement is required in the long term to ensure implementation.

• The issue of kite surfers needs to be addressed, as they do not need to pay fees like

boat owners do and yet they are a significant user group that pose a safety risk.

• The management and registration of private slipways.

• There is a potential threat of large houseboats – this is both a carrying capacity issue

and a water quality issue due to the waste they will produce.

• The culverts under roads in the wetland areas need to be cleared, and additional ones

are required to restore flow.

• A cooperative plan to address flood damage was developed in the past but has not

been implemented (a process is currently underway to determine the best approach in

conjunction with DEADP and a specialist engineer from Dept. Agriculture).

• Access to the sea in the Keurboomstrand area is a problem for non-residents (access

in other areas appears to be OK).

• Monitoring programmes must include the rivers and not just the estuaries.

• The number of business licenses to operate on the estuary (and procedure for

application and granting of licenses).

In addition to the above, the some of the mitigation measures recommended by the

Reserve Determination study (see Section 6.8.5) will be included in the EMP.



81

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APPENDIX I

CWAC counts for the Keurbooms River Estuary from 1997 to 2009 showing species

and total number (left) and count dates and overall total number of birds (right)

Species Total No. Count Date Total No.

African Black Oystercatcher 503 7/29/1995 1106

African Darter 44 1/21/1996 1695

African Fish-Eagle 24 7/20/1996 1365

African Sacred (Sacred) Ibis 1200 1/25/1997 2072

African Spoonbill 314 7/24/1997 857

Bar-tailed Godwit 34 2/3/1998 639

Black-headed Heron 6 8/13/1998 824

Black-necked Grebe 88 2/3/1999 1118

Blacksmith Lapwing (Plover) 214 7/13/1999 668

Black-winged Stilt 57 2/10/2000 625

Cape Cormorant 462 7/14/2000 697

Cape Shoveler 2 7/26/2001 1027

Cape Teal 20 2/5/2002 1569

Cape Wagtail 129 7/25/2002 664

Caspian Tern 30 1/17/2003 997

Cattle Egret 9 7/11/2003 561

Common (Whimbrel) Whimbrel 1070 1/23/2004 1112

Common Greenshank 753 4/6/2004 737

Common Moorhen 1 7/14/2004 726

Common Ringed Plover 418 1/24/2005 1519

Common Sandpiper 52 5/9/2005 719

Common Tern 611 7/22/2005 997

Curlew Sandpiper 1586 1/27/2006 1087

Egyptian Goose 423 7/10/2006 1314

Eurasian (Curlew) Curlew 18 1/18/2007 1104

Giant Kingfisher 12 8/10/2007 823

Great Crested Grebe 2 2/5/2008 1312

Greater Flamingo 43 7/14/2008 1163

Grey (Black-bellied) Plover 1932 2/23/2009 1133

Grey Heron 179 7/22/2009 821

Grey-headed Gull 2 Total Number 31051



86

APPENDIX I (continued)

Hadeda Ibis 35

Half-collared Kingfisher 5

Hybrid Duck 3

Kelp Gull 9183

Kittlitz's Plover 12

Lesser Flamingo 9

Little Egret 563

Little Grebe (Dabchick) 917

Little Stint 12

Mallard 61

Marsh Sandpiper 118

Osprey 8

Pied (Avocet) Avocet 254

Pied Kingfisher 112

Purple Heron 83

Red Knot 7

Red-billed Teal (Duck) 9

Red-knobbed Coot 1

Reed (Long-tailed) Cormorant 1850

Ruddy Turnstone 4

Ruff 3

Sanderling 2

Sandwich Tern 757

Spur-winged Goose 3

Swift (Great Crested) Tern 4953

Three-banded Plover 22

Unidentified Terns 325

Water Thick-knee (Dikkop) 220

White-breasted (Great) Cormorant 588

White-fronted Plover 622

Wood Sandpiper 42

Yellow-billed (Intermediate) Egret 1

Yellow-billed Duck 29

Total Number 31051



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APPENDIX II Reserve determinations conducted for the Keurbooms/Bitou quaternary catchments.

♣: Ecological Reserve + Basic Human Needs Reserve (BHNR).

♦: Low to very low confidence. The EWR at the outlet of quaternary catchment K60C is based on the natural flow of that specific catchment only

and does not include the flow contribution from upstream catchment.

♣: Ecological Reserve + Basic Human Needs Reserve (BHNR).

♦: Low to very low confidence. The EWR at the outlet of quaternary catchment K60C is based on the natural flow of that specific catchment only

and does not include the flow contribution from upstream catchment.

Quaternary

catchment River

Level of

Reserve

Quality /

quantity

Date template

signed by CD:

RDM

Notes PES EIS REC

% MAR

Ecological

Reserve

% MAR ♣

Surface

water

Reserve

(MCM/a)

vMAR

(MCM)

K60C Keurbooms Desktop ♦ Quantity 13/03/02 Incremental at the

outlet of quaternary

catchment K60C.

B Very

high

A 49.6 49.6 9.812 19.78

K60D Keurbooms Rapid III Quantity 14/08/07 Cumulative at the


catchment K60D.

B Very

high

B 33.6 33.601 48.238 143.56

K60E Keurbooms Rapid III Quantity 14/08/07 Cumulative at the


catchment K60E.

B Very

high

B 33.6 33.602 54.656 162.66

K60F Bitou Rapid III Quantity 10/03/06 Cumulative at EWR

Site 3. B Very

high

B 33.6 33.830 12.422 36.72

C.A.P.E. ESTUARY MANAGEMENT PROGRAMME · 2020-02-19 · C.A.P.E. Estuaries Programme Eden District...

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Transcript of C.A.P.E. ESTUARY MANAGEMENT PROGRAMME · 2020-02-19 · C.A.P.E. Estuaries Programme Eden District...