Coffs Harbour City Council

Coffs Harbour City Council

Boambee/Newports Processes Study Final

May 2010

22/14223/14101 Boambee/Newports Processes Study Final

Contents

Glossary 7

Abbreviations 16

Executive Summary i

1. Introduction 1

1.1 Background 1

1.2 Estuary Management Process 1

1.3 Study Aims and Objectives 4

2. Catchment Characteristics 5

2.1 Regional Characteristics 5

2.2 Study Area 5

2.3 Estuary Classification 6

2.4 Climate 7

2.5 Topography 10

2.6 Geology 10

2.7 Soils 10

3. Land Use 14

3.1 Previous Land Use 14

3.2 Existing Land Use 18

3.3 Future Land Use 21

4. Geomorphology 24

4.1 Introduction 24

4.2 Overview of the Geomorphology of the Boambee/Newports Estuary 24

4.3 Site Assessment 29

4.4 Upper Catchment 33

4.5 Historical Analysis 34

4.6 Climate Change Impacts on Geomorphology 34

4.7 Summary and Recommendations 35

5. Hydrology 36

5.1 Introduction 36


5.2 Hydrology Study Methodology 36

5.3 Description of Existing Hydrology 36

5.4 Predicted Future Hydrology 38

5.5 Hydrology Summary 39

6. Hydraulics 40

6.1 Introduction 40

6.2 Hydraulics Study Methodology 40

6.3 Description of Existing Hydraulics 40

6.4 Predicted Future Hydraulics 44

6.5 Hydraulics Summary 45

7. Water Quality 46

7.1 Introduction 46

7.2 Influences on Water Quality 52

7.3 Predicted Future Water Quality 54

7.4 Water Quality Summary 54

8. Biodiversity 56

8.1 Introduction 56

8.2 Biodiversity Study Methodology 57

8.3 Description of Flora Biodiversity 59

8.4 Terrestrial and Marine Fauna Biodiversity 71

8.5 Predicted Future Biodiversity 74

8.6 Biodiversity Summary 75

9. Foreshore and Waterway Use 76

9.1 Introduction 76

9.2 Foreshore and Waterway Use Study Methodology 76

9.3 Description of Existing Foreshore and Waterway Use 76

9.4 Predicted Future Foreshore and Waterway Use 80

9.5 Foreshore and Waterway Use Summary 80

10. Aboriginal and European Heritage 81

10.1 Introduction 81

10.2 Indigenous Heritage 81

10.3 Non - Indigenous heritage 83

10.4 Heritage Summary 84


11. Conclusion and Recommendations 85

12. References 86

Table Index Table 2-1 Geographical Limits of the Estuary (DNR, 2009) 5

Table 2-2 Catchment Data 6

Table 2-3 Monthly Climatic Conditions for Coffs Harbour (BOM, 2009) 8

Table 2-4 Summary of Climate Variables 9

Table 2-5 Soil Summary 11

Table 3-1 Land Use Proportions with the catchment 18

Table 4-1 Catchment Data 27

Table 4-2 Tidal Velocities – Average Maximums 28

Table 4-3 Erosion Categories and Description 29

Table 5-1 Estimated flood discharges at the mouth of Boambee Creek (CHCC USMP, 2000) 37

Table 6-1 Estimated Tidal Levels in Estuary (MHL, 2005) 42

Table 6-2 Maximum Velocities at Peak Discharge (MHL, 2005) 43

Table 6-3 Tidal Prisms for Boambee/Newports Estuary (MHL, 2005) 43

Table 7-1 CHCC Water Quality Data for Boambee Creek, 1999 to 2008 47

Table 7-2 Observed Water Quality Data from this Study 50

Table 7-3 MUSIC results at critical locations 55

Table 8-1 Summary of RARC Survey Results 62

Table 8-2 Coastal Saltmarsh Condition Index and Health Rating 68

Table 8-3 Mangrove Condition Index and Health Rating 69

Table 8-4 Seagrass Bed Condition Index and Health Rating 70

Figure Index Figure 1-1 Boambee/Newports Estuary Catchment 2

Figure 1-2 Estuary Management Process 3

Figure 2-1 Mean Maximum and Minimum Temperatures (°C) for Coffs Harbour 8

Figure 2-2 Average Monthly Rainfall for Coffs Harbour 9

Figure 2-3 Soil Landscapes 12

Figure 2-4 Acid Sulfate Soils 13

Figure 3-1 Banana Plantation Areas 1943 – 1994 15

Figure 3-2 Historical Aerial Photographs 16


Figure 3-3 Human Settlement Patterns 1954 to 1994 (Sawtell, 2002) 17

Figure 3-4 Coffs Harbour LEP 2000 – Land Use Zones 20

Figure 3-5 Land Use Changes and Pacific Highway Bypass Route (CHCC, 2007) 23

Figure 4-1 Catchment Characteristics and Geomorphic Zones 26

Figure 4-2 Bank Stability – Cordwells/Upper Boambee Estuary 30

Figure 4-3 Bank Stability Newports Estuary 31

Figure 4-4 Bank Stability Lower Boambee Estuary 32

Figure 4-5 Upstream view of Boambee Creek gravel deposits 33

Figure 4-6 Upstream view of large gravel deposit on a tributary of Cordwells Creek 34

Figure 6-1 Semi Diurnal Tidal Planes 41

Figure 7-1 Continuous Logger Results for Site 1 51



Figure 7-4 Water Quality Critical Locations 54

Figure 8-1 Physical Habitat Values (OzCoasts, 2009) 57

Figure 8-2 Riparian Vegetation Communities and Survey Site Locations 60

Figure 8-3 Changes in the Distribution of Estuarine Vegetation in Hectares 1954 – 1994 (Sawtell, 2002) 65

Figure 8-4 DNR Map of Estuarine Vegetation and Habitats 2007 (DNR, 2007) 66

Figure 9-1 Recreational Facilities 79

Appendices A MHL Water Quality Data

B Detailed Biodiversity Methodology

C User Survey

D AHIMS Database Search


Glossary

Acid sulfate soils Pyrite-rich marine clays, muds and sands that have become extremely acid following exposure to drainage as sulphur compounds are oxidised and converted to sulphuric acid.

Acidity The capacity of a compound that contains hydrogen (an acid) to dissociate in water (or in other solvents) to produce positively charged hydrogen ions. Acids react with a base or alkali (negatively charged) to form salt and water.

Aerobic Living or occurring only in the presence of oxygen.

Algae A diverse group of simple plants that contain chlorophyll and are capable of photosynthesis. Algae occur in both marine and freshwater, while other are terrestrial, living in damp situations on walls or trees, etc.

Algal bloom Proliferation of one or more phytoplankton species to high densities under favourable environmental conditions.

Alkalinity The capacity of a compound that can dissociate in water etc. to provide hydroxyl ions (OH-) that will neutralise acids to form salts and water.

Alluvial Material deposited by, or in transit in, flowing water.

Amphipod An order of animals that includes over 7,000 described species of shrimp-like crustaceans ranging from 1 to 140 mm in length

Anaerobic Environmental conditions where free oxygen is absent.

Annual Exceedance Probability (AEP)

The chance of a flood of a given or larger size occurring in any one year, usually expressed as a percentage.

Anthropogenic Man made. Usually used in the context of emissions that are produced as the result of human activities

Argillite A sedimentary rock, intermediate between shale and slate that does not possess true slaty cleavage

Australian Height Datum (AHD) A common national surface level datum approximately corresponding to mean sea level.

Average Recurrence Interval (ARI)

The long term average number of years between the occurrence of a flood as big as or larger than the selected event.

Bacteria Unicellular or multicellular micro-organisms with no true nucleus

Bank The relatively steep part of a river channel, generally thought of as being above the usual water level.

Benthic zone The bottom or bed of a water body.

Biodiversity The genetic variety of all life forms and their ecosystems; comprises genetic diversity (within species), species diversity and ecosystem diversity.

Bivalve Marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together


Catchment An area that drains all the precipitation that falls on it to a single point. Or the area of land drained by a stream or stream system. It can be simple, dealing with the water of one watercourse, or complex, having a number of internal subcatchments contributing to the whole. Catchment should not to be confused with watershed.

Chert A very fine-grained rock formed in ancient ocean sediments. It often has a semi glossy finish and is usually white, pinkish, brown, gray, or blue grey in colour.

Chlorophyll The pigment that gives plants their green colouring: it is required for the adsorption of light during photosynthesis

Clay Soil material composed of particles finer than 0.002 mm. When used as a soil texture group such soil contains at least 35% clay.

Cleavage The capacity of a rock to split along certain parallel surfaces more easily than along others.

Climate Change The long-term fluctuations in temperature, precipitation, wind, and all other aspects of the Earth's climate. External processes, such as solar-irradiance variations, variations of the Earth's orbital parameters (eccentricity, precession, and inclination), lithosphere motions, and volcanic activity, are factors in climatic variation.

Conductivity (electrical conductivity)

Conductivity is a measure of the ability of water to carry an electric current. This ability depends on the presence and concentration of ions. For water quality examination, this may be used as a measure of the concentration of ions present in the sample.

Contaminant Any chemical, physical, biological, or radiological substance that does not occur naturally or occurs at unnaturally high concentrations.

Convection Atmospheric or oceanic motions that are predominately vertical and that result in vertical transport and mixing of atmospheric or oceanic properties.

Crevasse splays Geographical feature which forms when an overloaded stream breaks a natural or artificial levee and deposits sediment on a floodplain

Delta A nearly flat plain of alluvial deposit between diverging branches of the mouth of a river, often, though not necessarily, triangular

Detritivore An organism that feeds on detritus or organic waste such as millipedes, woodlice, dung flies and many terrestrial worms.

Deposition The settling out or laying down of suspended, in-solution or other water-borne materials by a lessening of the velocity of the water or changes in water chemistry.

Discharge The rate of flow of water measured in terms of volume per unit time.

Drainage line A discernible natural depression along which surface water runoff concentrates and flows towards a stream, drainage plain or swamp.

Dredging A mechanical operation that may use heavy machinery to remove river material to improve the channel or as part of a mining operation.

Ebb Tide passing from high to low with the current going out to sea


E coli (Escherichia coli) Faecal bacteria found in the digestive tract of humans and other vertebrate animals, which are used to indicate contamination by human or animal faeces within an environment.

Ecologically sustainable development

Using, conserving and enhancing the community’s resources so that ecological processes, on which life depends, are maintained, and the total quality of life, now and in the future, can be increased.

Ecosystem An ecological community of various plants, animals, and other organisms, interacting with each other and with the nonliving resources in their environment, all functioning as a unit.

Eddy A circular movement of water or air that is formed where currents pass obstructions or between two adjacent currents that are flowing counter to ear other.

Effluent Something that flows out as liquid waste from industry, sewage works etc.

El Niño The extensive warming of the central and eastern Pacific that leads to a major shift in weather patterns across that Pacific. In Australia, El Niño events are associated with and increased probability of dry conditions

El Nino Southern Oscillation (ENSO)

Pressure systems in the South Pacific that trigger short-lived global changes in climate. Warm waters from the western Pacific move across the ocean, just below the equator, and significantly warm the eastern tropical Pacific.

Embankment The artificial bank built along a river to protect adjacent land from flood waters. Also called levee or dike.

Endangered species Wild species with so few individual survivors that the species could soon become extinct in all or most of its natural range.

Enterococci Bacteria which inhabit the intestines of humans and other vertebrates and are present in faeces. Used as an indicator of sewage pollution in the environment.

Epiphytic Derives moisture and nutrients from the air and rain; usually grows on another plant but not parasitic on it

Erosion The wearing away of the land and removal of soil by running water, rain, wind, ice or other geological agents, including such processes as detachment, entrainment, suspension, transportation and mass movement.

Estuary Regions of interaction between rivers and near-shore ocean waters, where tidal action and river flow cerate a mixing of fresh and salt water.

Euryhaline Species capable of tolerating a wide range of salt water concentrations

Eutrophication Process of enrichment of nutrients, especially nitrogen and phosphorous.

Evapotranspiration The discharge of water from the Earth’s surface to the atmosphere by evaporation from bodies of water, or other surfaces, and by transpiration from plants


Facies Facies is the term to describe a distinctive assemblage of sedimentary rock which characterise a sediment as having been deposited by a particular process or environment.

Faecal coliforms Bacteria which inhabit the intestines of humans and other vertebrates and are present in the faeces. Used as a primary indicator of sewage pollution in the environment.

Fauna The animal life of a region.

Feldspathic Materials that contain feldspar. Feldspar is the name of a group of rock-forming minerals which make up as much as 60% of the Earth's crust.

Flagellate Single celled organisms with one or more whip-like organelles called flagella

Flood-tide Tide passing from low to high with the current going toward the shore or up a tidal river estuary

Flora The plant life of a region.

Fluvial Relating to or occurring in a river.

Gastropod Soft bodies animals with a head, visceral body mass and a mantle, often protected by a shell.

Geology The branch of science that deals with the earth's history, particularly its physical history, as recorded in the substrate and the fossil record .

Geomorphology The study of present-day landforms, including their classification, description, nature, origin, development and relationships to underlying structures. Also the history of geologic changes as recorded by these surface features. The term is sometimes restricted to features produced only by erosion and deposition.

Gley The grey or greenish-grey colouration found in soils. It is often produced under conditions of poor drainage, which give rise to chemical reduction of iron and other elements.

Greywackle A variety of sandstone generally characterised by its hardness, dark colour and poorly-sorted, angular grains of quartz, feldspar and small rock fragments set in compact, clay-fine matrix

Groundwater Water stored underground in rock fractures and pores.

Gully Erosion Gully erosion is the removal of soil along drainage lines by surface water runoff. Gully erosion occurs when water is channelled across unprotected land and washes away the soil along the drainage lines.

Heathland Dwarf-shrub habitat found on mainly infertile acidic soils, characterised by open, low growing woody vegetation. The soils are usually acidic siliceous sands of low fertility, although some heathlands also occur on limestone, peats and clays.

Higher High Water (Spring Solstices)

The highest of the high waters (or single high water) of any specified tidal day due to the declination in the effects of the Moon and Sun.

High Water Slack The period of quiet water when the tide reverses from flood to ebb.

Holocene The most recent epoch of the Quaternary period, covering


approximately the last 10,000 years.

Humic Referring to the organic matter within a soil.

Hydrograph A graph which shows haw to discharge of stage/flood level at any particular location changes with time during a flood.

Hydrology The science dealing with the properties, distribution and circulation of water.

Hydraulics Term given to the study of water flow in waterways, in particular, the evaluation of flow parameters such as water level and velocity.

Indian Spring Low Water Indian Spring Low Water - A datum originated by Professor G. H. Darwin when investigating the tides of India. It is an elevation depressed below mean sea level by an amount equal to the sum of the amplitudes of the harmonic constituents M2, S2, K1, and O1.

Infiltration The downward movement of water into the soil. It is largely governed by the structural condition of the soil, the nature of the soil surface (including presence of vegetation) and the antecedent moisture content of the soil.

Intertidal The zone of shore between the high water mark and low water mark.

Jasper An opaque and fine grained quartz.

Krasnozems Deep, red, strongly structured clay soil with clay content gradually increasing with depth, and weak horizon differentiation.

Lithology The scientific study and description of rocks, especially at the macroscopic level, in terms of their colour, texture and composition

Lithosol A shallow soil showing minimal profile development and dominated by the presence of weathering rock and rock fragments.

Littoral Rainforest Littoral Rainforest occurs close to the sea (generally within 2km) where there is exposure to salt-laden winds. Rainforest plants dominate the area - vines can form a major part of the canopy along with trees such as Eucalypts and Banksias.

Low Water Slack The period of quiet water when the tide reverses from ebb to flood.

Macrophyte A plant that can be seen without magnification.

Marsh A type of wetland that does not accumulate appreciable peat deposits and is dominated by herbaceous vegetation. Marshes may be fresh or saltwater, tidal or nontidal.

Mean High Water The average of all the high water heights observed over the National Tidal Datum Epoch. For stations with shorter series, simultaneous observational comparisons are made with a control tide station in order to derive the equivalent datum.

Mean High Water Neaps Long term average of the heights of two successive high waters when the range of tide is the least, at the time of first and last quarter of the moon.

Mean High Water Springs Long term average of the heights of two successive high waters during those periods of 24 hours (approximately once a fortnight) when the range of tide is greatest, at full and new moon.

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Mean Low Water Neaps The long term average value of two successive low waters over the same periods as defined for Mean High Water Neaps.

Mean Low Water The average of all low waters observed over a sufficiently long period (preferably over the national tidal datum epoch). For stations with shorter series, simultaneous observational comparisons are made with a control tide station in order to derive the equivalent datum.

Mean Low Water Springs The long term average value of two successive low waters over the same periods as defined for Mean High Water Springs.

Mean Tide Level The arithmetic mean of all heights of low and high waters over a period of time. Must not be confused with mean sea level.

Micro-organisms Organisms which are invisible or only barely visible with the unaided eye.

Natural flow Discharge that occurs naturally through climate and geomorphology without regulation and diversion or other modification.

Neap-tide A tide in which the difference between high and low tide is the least. Neap tides occur twice a month when the Sun and Moon are at right angles to the Earth. When this is the case, their total gravitational pull on the Earth's water is weakened because it comes from two different directions.

Non-potable water Water suitable for purposes not requiring a potable supply.

NTU (nephelometric turbidity unit) Units of measure of the turbidity of water due to suspended, colloidal and particulate matter, measure using a nephelometer.

Nutrient Any substance assimilated by living things that promotes growth.

Organic Of animal or vegetable origin.

Outfall Outlet of a water body, drain or culvert.

Peak discharge The maximum discharge occurring during a flood event.

Permeability The characteristic of a soil, soil horizon or soil material which governs the rate at which water moves through it.

pH Value taken to represent the acidity or alkalinity of an aqueous solution. It is defined as the negative logarithm of the hydrogenion concentration of the solution.

Photosynthesis The manufacture by plants of carbohydrates and oxygen from carbon dioxide and water in the presence of chlorophyll with sunlight as the energy source. Oxygen and water vapour are released in the process.

Phytoplankton That portion of the plankton community comprised of tiny plants (e.g., algae and diatoms).

Plankton Plants (phytoplankton) and animals (zooplankton), usually microscopic, floating in the surface layer of a water body.

Pleistocene The earlier of the two epochs of the Quaternary period, starting 2 to 3 millions years before the present and ending about 10,000 years ago. It was a time of glacial activity.

Podzol Acid sandy soil with strongly differentiated horizons including a


bleached horizon above a coffee coloured pan and coloured subsoil.

Polychaete Any of a class of primarily marine, annelid worms that have a pair of fleshy, leg-like appendages covered with bristles on most segments

Potable water Water suitable for human consumption by or fit for the preparation of foods.

Quaternary Period The latest period of geologic time, covering the most recent 2 million years of the Earth’s history. It is divided into two epochs: the Pleistocene and the Holocene.

Precipitation Any or all forms of liquid or solid water particles that fall from the atmosphere and reach the Earth’s surface. It includes drizzle, rain, snow, snow pellets, snow grains, ice crystals, ice pellets and hail.

Primary-contact recreation Direct contact with water, including swimming, diving, water skiing and surfing.

Rhizome Horizontal, underground plant stem capable of producing the shoots and root systems of a new plant.

Rill erosion Erosion resulting from movement of soil by a network of small, shallow channels.

Riparian Relating to or inhabiting the banks of a natural course of water.

Run-off The difference in quantity between precipitation and the combination of evaporation and transpiration. The resulting water that supplies rivers and lakes after evaporation and transpiration have occurred. Includes water that soaks into the earth and is available as groundwater. Surface run-off does not include groundwater.

Salinity The degree of salt in water.

Salt Marsh Area of low, flat, poorly drained ground that is subject to daily or occasional flooding by salt water or brackish water that is covered with a thick mat of grasses and such grasslike plants as sedges and rushes.

Salt Water Intrusion The invasion of fresh, surface, or groundwater by salt water.

Sclerophyll Hard, leathery-leafed plants, such as eucalypts.

Sedgeland Wet area dominated by grasslike or rushlike plants with solid stems, narrow grasslike leaves and spikelets of inconspicuous flowers

Sediment Soil or other particles that settle to the bottom of lakes, rivers, oceans and other waters.

Sedimentation Deposition of sediment, typically by water.

Semi-diurnal Tides which have a period or cycle of approximately half of one tidal day (about 12.5 hours). Semidiurnal tides usually have two high and two low tides each day.

Sewage The used water of a community or industry, containing dissolved and suspended contaminants.

Sheet erosion Erosion of soil from across a surface by uniform action of rain or flowing water.


Shoal A linear landform within or extending into a body of water, typically composed of sand, silt or small pebbles. Shoals are generally long and narrow and develop where a stream or ocean current promotes the deposition of granular material.

Silt Fine soil particles in the size range 0.02-0.002 mm

Solonchaks Pale or grey soil type found in arid to subhumid, poorly drained conditions.

Spring -tide A tide in which the difference between high and low tides is the greatest. Spring tides occur twice a month at the time of new moon or full moon when the sun, moon and earth are approximately aligned. When this is the case, their collective gravitational pull on the Earth's water is strengthened.

Stormwater Rainwater that runs off the land, frequently carrying various forms of pollution such as litter and detritus, animal droppings and dissolved chemicals. This untreated water is carried in stormwater channels and discharged directly into creeks, rivers, the harbour and the ocean.

Stratification Separating into layers.

Streambank Erosion The direct removal of banks and beds by flowing water.

Subtidal The benthic ocean environment below low tide that is always covered by water.

Subtropical A type of rainforest occurring between the tropics and temperate geographic regions; found between tropic and temperate conditions.

Supratidal The zone that extends from the higher high water line of the mean tides.

Suspended solids The portion of total solids in a sample of water retained by a filter.

Taxonomy The classification of living organisms according to the hierarchy of relationships.

Temperate Moderate or mild climatic conditions

Terrestrial The total infrared radiation emitted by the Earth and its atmosphere in the temperature range of approximately 200-300K. Because the Earth is nearly a perfect radiator, the radiation from its surface varies as the fourth power of the surface’s absolute temperature.

Tidal Marsh Low, flat marshlands traversed by channels and tidal hollows and subject to tidal inundation; normally, the only vegetation present are slat-tolerant bushes and grasses.

Tidal Prism Volume of water that flows into a tidal channel and out again during a complete tide, excluding any upland discharges.

Topsoil A part of the soil profile, typically the A1 horizon, containing material which is usually darker, more fertile and better structured than the underlying layers.

Toxicant An agent or material capable of producing and adverse response in a biological system, seriously injuring structure or function or causing death.


Transpiration The process in plants by which water is taken up by the roots and released as water vapour by the leaves. The term can also be applied to the quantity of water thus dissipated.

Tributary A stream or river which flows into a mainstream river.

Tripartite zonation A geomorphologic term referring to the arrangement of a estuary into three zones: a river dominated bay-head delta and alluvial plain at the head; a low energy central basin rimmed by intertidal environments; and a coast-parallel barrier and flood- and ebb-tidal deltas at the mouth.

Turbidity A condition in water caused by the presence of suspended matter resulting in the scattering and absorption of light, and suspended solids imparting a visible haze or cloudiness to the water, which can be removed by filtration. An analytical quantity usually reported in Nephelometric Turbidity Units (NTUs) determined by light scattering.

Wastewater The used water of a community or industry, containing dissolved and suspended contaminants.

Water quality The chemical, physical and biological condition of water.


Abbreviations ADCP Acoustic Doppler Current Profiler

AEP Annual Exceedance Probability

AHD Australian Height Datum

AHIMS Aboriginal Heritage Information Management System

ANZECC Australian and New Zealand Environment and Conservation Council

ARI Average Recurrence Interval

ASS Acid Sulfate Soil

BOM Bureau of Meteorology

CEMAC Coastal Estuary Management Advisory Committee

CHCC Coffs Harbour City Council

CSIRO Commonwealth Scientific and Industrial Research Organisation

DECCW NSW Department of Environment, Climate Change and Water

DIPNR NSW Department if Infrastructure, Planning and Natural Resources

DNR NSW Department of Natural Resources

DO Dissolv ed Oxygen

DoP NSW Department of Planning

DPI NSW Department of Primary Industries

DWE NSW Department of Water and Energy

EC Electrical Conductivity

EEC Endangered Ecological Communities

EPBC Environment Protection and Biodiversity Conservation Act 1999

GIS Geographic Information Systems

HHW (SS) Higher High Water (Spring Solstices)

ICOLL Intermittently Closed and Open Lake or Lagoon

ISLW Indian Spring Low Water

MHL Manly Hydraulic Laboratory

MHW Mean High Water

MHWN Mean High Water Neaps

MHWS Mean High Water Springs

MLW Mean Low Water

MLWN Mean Low Water Neaps

MLWS Mean Low Water Springs

MTL Mean Tide Level

NES National Environmental Significance

OSSM On Site Sewer Management System

PAR Photosynthetically Activated Radiation

RARC Rapid Appraisal of Riparian Condition

RTA Roads and Traffic Authority, NSW

RVC Regional Vegetation Communities


UNSW University of New South Wales

WDD Wave Dominated Delta

i 22/14223/14101 Boambee/Newports Processes Study Final

Executive Summary

Background

Estuaries form important ecosystems that have numerous environmental, social and economic values. It is therefore important we protect and sustainably manage our estuaries.

Coffs Harbour City Council (CHCC) recognises the need to minimise human impacts on the estuarine environment of Boambee/Newports Estuary and to ensure that the natural resources of the estuary are managed to meet both the present and future needs. To achieve this, and to be consistent with the NSW Estuary Management Policy (1993), CHCC are committed to implementing the estuary management process.

The Estuary Management Program provides an eight step process to promote cooperation between the various Authorities, landholders and estuary users in the development and implementation of Estuary Management Plans. CHCC established the Coastal Estuary Management Advisory Committee (CEMAC) to advise on estuarine matters and oversee the preparation of management studies and plans in accordance with the NSW Estuary Management Policy. The committee determined that the Boambee/Newports Estuary was a high priority and funding was sought for preparation of a Processes Study and Estuary Management Study/Plan.

The primary objectives of the Processes Study and Estuary Management Study/Plan for the Boambee/Newports Estuary system were identified by CEMAC to be:

Navigation restriction due to sedimentation of the lower reaches;

Bank erosion and bank protection;

Water quality and pollution;

Biodiversity;

Improvements to aquatic and terrestrial habitats;

Environmental restoration of degraded areas;

Community education; and

Recreational use.

Study Aims and Objectives

This Estuary Processes Study comprises the third step of the Estuary Management Program. The aim of the Study is to define the ‘baseline’ conditions of the various estuary processes, and the interaction between these processes. To achieve this aim, the objectives of this Study are to:

Provide a description of the estuary characteristics;

Assess and document the shoaling, bank erosion, water quality, biodiversity, foreshore use and heritage processes and issues within the Boambee/Newports Estuary; and

Predict future processes and issues of significance within the Boambee/Newports Estuary.

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Catchment Description

The Boambee/Newports Estuary is located on the Mid North Coast of NSW, in between the city of Coffs Harbour (to the north) and the town of Sawtell (to the south).

The Boambee/Newports Estuary has a roughly rectangular shape catchment area of approximately 49 km2. It extends about 8 km from the coast with a coastal floodplain of approximately 3 km wide. It consists of three main tributaries: the largest being Newports Creek in the north; Boambee Creek is next largest and drains the middle portion of the catchment; and Cordwells Creek the smaller of the catchments drains the south. The Boambee/Newports Estuary is permanently open to the ocean and has no artificial entrance training works, as it is naturally trained by Boambee Headland on the southern side.

The Boambee/Newports Estuary is classified as a Wave Dominated Delta (WDD). WDDs consist of a river/creek that is directly connected to the ocean by a channel that is typically flanked by floodplain vegetation and swamps. WDDs are distinguished by a moderately high wave influence (compared to tidal influence) at the mouth. The estuary mouths of WDDs are typically narrow due to a barrier (sandbar) and are rarely closed off because of the relatively high river influence within the system.

The climate of the Boambee/Newports Estuary catchment is subtropical with warm to very warm wet summers and cool to mild, relatively dry winters.

It is increasingly clear that the climate is changing at a faster rate than previously experienced. The predicted changes in climate have the potential to impact the Boambee/Newports Estuary.

Land Use

Following European settlement, land use was dominated by timber cutting, which flourished after the completion of the Coffs Harbour jetty in 1892. Banana growing then became a popular activity with Coffs Harbour being considered the major banana producing area in Australia in the 1920’s. Banana growing hit its peak in the 1960’s and 1970’s but has been in a steady decline ever since.

Between 1984 and present, there has been significant growth in the urbanisation of the Boambee/Newports Creek catchment. The large industrial areas in the mid catchment were also developed or being developed during this period. Other developments in the mid-catchment during this period included the university, some recreational areas and the sewage treatment plant.

Significant land use changes are expected within the catchment in the future with over 130 hectares identified for possible residential development, 73.5 hectares for possible industrial development and 46 hectares for possible rural residential.

A four-lane dual carriageway Pacific Highway Bypass is also proposed to be constructed within the catchment in the future.

Geomorphology

The Boambee/Newports Estuary in respect to its geomorphic form is in general good condition. Banks are largely stable to minimally active and the general form of the estuary has remained

iii 22/14223/14101 Boambee/Newports Processes Study Final

more or less unchanged over the period of record covered by historical aerial imagery. The shoaling patterns within the marine zone have also remained relatively stable over the last 65 years, with no significant net increase or decrease in bar extents.

Upper catchment processes have improved as areas of banana plantations have decreased however development has increased which may lead to an altered run-off regime. The effects of climate change are also likely to increase the rate of bank erosion.

Hydrology

The hydrologic analysis indicates that it is not expected that there would be an increase in the peak rates of surface runoff as a result of future development within the study area. WMAwater are in the process of completing a flood study for the area and this will define the existing flooding regime. Results available from that study indicate a flow attenuation through the estuarine area.

The results of the predictions indicate that there will be an increase in the annual water yield with further planned development within the catchment without the implementation of specific measures to mitigate that change in yield.

Hydraulics

The hydraulic processes in the estuary are characterised by the semi-diurnal ocean tide in conjunction with hydrologic surface runoff contributed by the Boambee/Newports Creek catchment.

The tidal range in the estuary is largest at the mouth and reduces upstream to the tidal limits. The lag time between high and low tide in the estuary increases with distance upstream from the mouth.

Tidal velocities and discharges are greatest at the mouth followed by Boambee Creek and then Newports Creek.

Entrance conditions, rainfall and development are considered to influence the hydraulics of the estuary.

The 100 year ARI flood level ranges from 2.6 m AHD at the railway line crossing of Boambee Creek to 6 m AHD at the Pacific Highway crossing of Newports Creek.

Impacts of climate change are likely to increase the areas of inundation and the extent of affectation of sea waters within the estuary.

Water Quality

The achievement of high quality water in the Boambee/Newports Estuary is particularly important for local community as it is used extensively for a variety of recreational activities.

The monitoring results have shown that the ANZECC trigger values for some parameters analysed have been exceeded at some locations. The most significant impacts on water quality are likely to be land use and sewer overflows.

The results of the MUSIC model at several critical locations show that without the implementation of mitigation works the future development of the catchment is predicted to

iv 22/14223/14101 Boambee/Newports Processes Study Final

result in a significant increase in pollutant loadings. However, with the implementation of appropriate mitigation measures it would be possible to remove the effect of the increased urban development on the pollutant loads.

Biodiversity

The existing level of biodiversity in the Boambee/Newports Estuary is considered high based upon the estuarine and riparian vegetation survey results and the DECCW, EPBC, Bionet and DPI Fisheries database searches.

In undertaking the survey, it was expected that human interference would be evident in the form of heavy weed infestations, rubbish and general overuse of the waterways and adjacent terrestrial vegetation communities. This was the case, but at a level much lower than was expected, especially in consideration of the Estuary being surrounded by residential, industrial and commercial development. However, as human development expands, the health and condition of the Estuary and broader catchment is expected to decline over the long-term, thus reducing habitat values that are vital to the persistence of threatened flora and fauna.

Foreshore and Waterway Use

Foreshore and waterway use will provide direction on the management of the Estuary. To establish an understanding of the people using the Estuary, a survey was conducted.

Predictably, the survey indicated that the majority of the people using the Estuary are from the local area. The survey also revealed that people of all ages used the Estuary with most people using the Estuary regularly. The most popular section of the Estuary is the lower section that includes Boambee Creek Reserve and Boambee Beach.

The Estuary is used for a variety of recreational activities, including:

Swimming Dog Exercising

Fishing Relaxing

Snorkelling Walking

BBQs/Picnics Boating/Kayaking

It is predicted that Boambee/Newports Estuary will continue to be a popular location for foreshore and waterway use, with the number of people using the Estuary likely to increase. The only factor potentially reducing the number of people using the Estuary is a decrease in water quality, fish stocks or facilities.

Heritage

Waterways, and water, have important spiritual and cultural significance for Aboriginal people. Waterways were also a focal point for explorers and settlers with many NSW towns located near them. To assess the heritage characteristics of the Boambee/Newports Estuary, a search of available information has been undertaken.

The assessment uncovered records of over 60 aboriginal artefacts and sites spread throughout the catchment. This included the largest artefact scatter so far recorded in the Coffs Harbour district which was located in the North Boambee Valley.

v 22/14223/14101 Boambee/Newports Processes Study Final

Although settlers have occupied the land within the catchment since the early 1880s, most of the existing buildings are of more recent construction. As revealed by the searches, no sites or places of acknowledged historic cultural heritage significance have been identified in the catchment area.

Conclusion/Recommendations

The main concerns that have been identified by the Study and require management, include:

Inappropriate land use and development, especially in the upper catchment;

The predicted impacts of climate change;

The presence of noxious weeds in most riparian vegetation communities that appears to increase further up the catchment;

Habitat destruction through uncontrolled vehicular access that has resulted in substantial damage to the Estuary’s coastal saltmarsh communities;

Vegetation clearing which may lead to reduced biodiversity value and an increase in habitat fragmentation;

The large areas proposed for development within the catchment and the potential associated impacts;

Gross pollution; and

A lack of information.

It is recommended that the Estuary Management Study and Estuary Management Plan provide a range of practical and effective management actions to address these and other issues. The aim of these management actions should be to ensure the sustainable health of the Boambee/Newports Estuary.

1 22/14223/14101 Boambee/Newports Processes Study Final

1. Introduction

1.1 Background

Estuaries form important ecosystems that have numerous environmental, social and economic values. The essential characteristics of an estuary are the influence of tidal processes on water levels and discharges, this influence being transmitted through a permanent or intermittent connection with the ocean, together with a variable salinity caused by the mixing of ocean water with freshwater runoff from the land (DNR, 2009).

Estuaries support a diverse array of habitats including mangroves, salt marsh, seagrass and mud flats. They are known as the “nurseries of the sea” and support a diversity of wildlife, including shore birds, fish, prawns, crabs, oysters and other shellfish, marine worms, marine mammals and reptiles. Much of the natural resources fostered by estuaries support valuable commercial enterprises including fishing, building and tourism. Estuaries also improve water quality and provide protection from storm and flood damage.

It is therefore important we protect and sustainably manage our estuaries.

The Boambee/Newports Estuary is located on the Mid North Coast of NSW, in between the city of Coffs Harbour (to the north) and the town of Sawtell (to the south), as shown in Figure 1-1.

The Boambee/Newports Estuary has a roughly rectangular shape catchment area of approximately 49 km2. It extends about 8 km from the coast with a coastal floodplain of approximately 3 km wide. It consists of three main tributaries: the largest being Newports Creek in the north; Boambee Creek is next largest and drains the middle portion of the catchment; and Cordwells Creek the smaller of the catchments drains the south. The Boambee/Newports Estuary is permanently open to the ocean and has no artificial entrance training works, as it is naturally trained by Boambee Headland on the southern side.

Coffs Harbour City Council (CHCC) recognises the need to minimise human impacts on the estuarine environment of Boambee/Newports Estuary and to ensure that the natural resources of the estuary are managed to meet both the present and future needs. To achieve this, and to be consistent with the NSW Estuary Management Policy (NSW Water Resources, 1993), CHCC are committed to implementing the estuary management process.

1.2 Estuary Management Process

To effectively manage our estuaries, the NSW Estuary Management Policy was adopted in 1993. This Policy was created to achieve integrated, balanced, responsible, and ecologically sustainable use of the State’s rivers and estuaries. To implement the Policy the Estuary Management Program was developed. The Estuary Management Program provides an eight step process to promote cooperation between the various Authorities, landholders and estuary users in the development and implementation of Estuary Management Plans. The eight steps are shown in Figure 1-2.

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Figure 1.1

Job NumberRevision A

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Map Projection: Transverse MercatorHorizontal Datum: Geocentric Datum of Australia (GDA)

Grid: Map Grid of Australia 1994, Zone 56

0 360 720 1,080 1,440180

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LEGEND

o© 2009. While GHD has taken care to ensure the accuracy of this product, GHD and COFFS HARBOUR CITY COUNCIL make no representations or warranties about its accuracy, completeness or suitability for any particular purpose. GHD and COFFS HARBOUR CITY COUNCIL cannot accept liability of any kind(whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.

Date 29 JUN 2009

Coffs Harbour City CouncilBoambee / Newports Estuary

Boambee / Newports EstuaryCatchment

Data Source: Coffs Harbour City Council: Aerial - 2006; Coffs Harbour City Council: Catchment Data - 2008. Created by: fmackay, Gismodelling

2/115 West High Street Coffs Harbour NSW 2450 T 61 2 6650 5600 F 61 2 6652 6021 E W www.ghd.com.au

1:45,000 (at A4)

CatchmentsEstuary

!( Approx. Tidal Extent

N S WN S WDubbo

Cobar

Bourke

Bathurst

Tamworth

Cooma

Wagga Wagga

Bega

Sydney

Newcastle

Broken Hill

Coffs Harbour

Port Macquarie


Form an Estuary Management Committee

Assemble Existing Data

Estuary Processes Study Define the ‘baseline’ condition of estuary processes, such as:

Hydraulics: tidal, freshwater, flushing, salinity, water quality and sediment behaviour etc. Biology: habitats, species, populations, endangered species etc.

Impacts: impact of human activities on hydraulics and biology.

Estuary Management Study Define management objective, options and impacts by detailing:

Essential Features: physical, chemical, ecological, economic, social and aesthetic. Current Uses: activities, land tenure and control, conflicts of use.

Conservation Goals: preservation, key habitats. Remedial Goals: restoration of economic quality.

Development: acceptable commercial and public works and activities. Management Objectives: identification and assessment.

Management Options: implementation of options. Impacts: impact of proposed management measures.

Draft Estuary Management Plan Recommend activities that need to be undertaken to achieve the estuary

management objectives.

Review Draft Estuary Management Plan Exhibit EMP

Review and finalise EMP

Adopt and Implement Management Plan Council adopt EMP

Estuary Management Committee to implement EMP

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 8

Step 1

Monitor and Review Baseline and event monitoring

Assess the success of EMP Review EMP if necessary

THIS STUDY

Figure 1-2 Estuary Management Process

CHCC established the Coastal Estuary Management Advisory Committee (CEMAC) to advise on estuarine matters and oversee the preparation of management studies and plans in accordance with the NSW State Rivers and Estuary Management Policy. The committee determined that the Boambee/Newports Estuary was a high priority and funding was sought for preparation of a Processes Study and Estuary Management Study and Plan.

The primary objectives of the Processes Study and Estuary Management Study/Plan for the Boambee/Newports Estuary were identified by CEMAC to be:

Navigation restriction due to sedimentation of the lower reaches;

Bank erosion and bank protection;


Water quality and pollution;

Biodiversity;

Improvements to aquatic and terrestrial habitats;

Environmental restoration of degraded areas;

Community education; and

Recreational use.

1.3 Study Aims and Objectives

This Study comprises the third step of the Estuary Management Program. The aim of the estuary processes study is to define the ‘baseline’ conditions of the various estuary processes, and the interaction between these processes. To achieve this aim, the objectives of this Study are to:

Provide a description of the estuary characteristics;

Assess and document the shoaling, bank erosion, water quality, biodiversity, foreshore use and heritage processes and issues within the Boambee/Newports Estuary; and

Predict future processes and issues of significance within the Boambee/Newports Estuary.

1.3.1 Study Limitations

All efforts were made to provide an accurate and up-to-date representation of the estuary conditions but the Study was subject to some limitations, including:

The Study relied heavily on existing information. In some situations, this information may have been dated or been compiled using a different methodology. Available information may have also had data gaps that have made a comprehensive assessment of the estuary conditions difficult. The Study also adopts any of the limitations inherent in the available information;

The short timeframe of the Study limited the temporal assessment of estuary conditions; and

Higher than average rainfall conditions, including a reported 1 in 100 rain event, may have influenced some of the conditions of the estuary during the assessments.

Other limitations are mentioned in the individual Sections of the Study report.


2. Catchment Characteristics

2.1 Regional Characteristics

The Boambee/Newports Estuary is part of the NSW North Coast Bioregion that extends from southeast Queensland to the Barrington Tops in central eastern NSW. The bioregion is characterised by basalt soils that support sub-tropical and warm temperate rainforests, or wet sclerophyll forests in the north of the region. The estuaries of the region are characterised by mangrove, saltmarsh and seagrass communities. The freshwater margins are typically characterised by Swamp Oak (Casuarina glauca) and Broad-leaved Paperbark (Melaleuca

quinquenervia) forests, whilst riparian and alluvial river flats are typically characterised by Flooded Gum (Eucalyptus grandis) forests (DECC, 2008).

The Estuary is also part of the marine Tweed-Moreton Bioregion that extends from southern Queensland (25°S) south to Nambucca Heads in NSW (30° 40'S) and out to the edge of the continental shelf at about the 200 m depth contour (NSW Marine Parks, 2005). The bioregion is characterised by a range of exposed and sheltered sandy beaches, rocky shores, 'coffee rock' reefs, submerged pinnacles, small rocky islands, coral communities, riverine estuaries, coastal creeks and lakes, and a variety of sandy seabed habitats (NSW Marine Parks, 2005).

2.2 Study Area

This Study concentrates on the tidal limits of the estuary. Each branch of the Estuary has tidal and mangrove limits located in close proximity to geographical features (DNR, 2009). The tidal limits are located further up each branch than the mangrove limits, therefore the tidal limits were chosen as the upstream limit of the Estuary for this Study. The mouth of the Estuary provides the downstream limit. Details pertaining to the limits of the Estuary are depicted in Table 2-1 and Table 2-2.

Table 2-1 Geographical Limits of the Estuary (DNR, 2009)

Location Coordinates

Estuary Branch Location of Tidal Limit Eastings Northings Grid Reference

Distance (km) from Estuary Entrance

Boambee Creek 140 m upstream from bridge on Lindsays Road, Coffs Harbour

506704 664 3953 56 7.1

Newports Creek Old concrete weir 600 m upstream from Pacific Highway, Coffs Harbour

508614 664 6588 56 8.2

Cordwells Creek At weir, at rear of 21-23 Avonleigh Drive, Coffs Harbour

506959 664 2928 56 7.3


The catchment area, estuary area, adopted estuary depth and estuary volume of the three tributaries is provided in Table 2-2. This shows that Newports Creek has the largest catchment area but the Boambee Creek has the largest estuary area. Cordwells Creek has the smallest catchment area and estuary area. All tributaries are relatively shallow with adopted depths ranging between 1.25 m and 1.75 m.

Table 2-2 Catchment Data

Estuary Catchment Area

(km2) Estuary Area

(m2) Adopted Estuary

Depth (m) Estuary Volume

(m3)

Newports 27.94 209,221 1.75 366,136

Boambee 12.98 561,614 1.5 842,421

Cordwells 8.44 31,798 1.25 39,747

Total 49.36 802,633 N/A 1,248,304

2.3 Estuary Classification

The Boambee/Newports Estuary is classified as a Wave Dominated Delta (WDD). WDDs are distinguished by a moderately high wave influence (compared to tidal influence) at the mouth. The estuary mouths of WDDs are typically narrow due to a barrier (sandbar) and are rarely closed off because of the relatively high river influence within the system. The influence of waves declines quickly adjacent to the entrance of the mouth. River influence becomes dominant further inland as tides are attenuated into channels (Ryan et al 2003).

A WDD is the mature form of a Wave Dominated Estuary, which has been infilled by terrestrial and marine sediments. During the late stages of sediment infilling the connectivity between the river channel and tidal inlet increases which results in effective delivery of sediment downstream and creates swampy areas adjacent to the creek. Due to this process, the habitats of WDDs are relatively stable and persist for many years with minimal change (Ryan et al 2003).

WDDs characteristically support euryhaline (capable of tolerating a wide range of salt water concentrations) species as well as transient visitors from the ocean depending on flow conditions. Intertidal habitats are typically limited in extent. This type of delta usually supports a high-energy sandy beach along with tributary channels, intertidal mudflats, saltmarshes and mangroves along with various species of seagrass on the sandy channel margins (Ryan et al 2003).

Key Features of a WDD

The key features of a WDD include the following (Ryan et al 2003):

Supports variable ecosystems including brackish subtidal, intertidal and supratidal habitats;

Marine flushing is restricted due to the narrow mouth, with only a small amount of water is exchanged during each tide;

High river flow with seasonal flooding removing marine water and flushing sediment of the delta;


Turbidity is naturally low except during flood events;

Sediment and the majority of contaminants are usually expelled into the ocean;

Short residence time of water equals minimal processing or trapping of nutrients;

Evolutionary “mature”; and

Tends to be stable morphologically.

2.4 Climate

The Boambee/ Newports Creek Estuary is representative of the local Coffs Harbour climate. Coffs Harbour's climate is subtropical with warm to very warm wet summers and cool to mild, relatively dry winters. The proximity of the coast ensures that the temperatures are moderated by the influence of the sea. The proximity of the ranges west of Coffs Harbour means that the summer cooling sea breezes do not penetrate more than a few kilometres from the coast, resulting in warmer temperatures inland than on the coastal fringe (BOM, 2009).

Average maximum daily temperatures range from 18.7° C in winter to 26.9° C in summer, while average minimum daily temperatures range from 7° C in winter to 19° C in summer, as shown in Table 2-3 and graphically depicted in Figure 2-1.

Annual mean rainfall is 1,676.1 mm, with the wettest month having an average of 239.3 mm and the driest month receiving an average of 63 mm, as shown in Table 2-3 and graphically depicted in Figure 2-2. From November to April winds blow most frequently from the NE to the SE. From June to August the winds blow most from the SW to NW. The remaining months are generally transitional from one regime to the other (BOM, 2009).

2.4.1 Climate Change

It is increasingly clear that our climate is changing at a faster rate than previously experienced. A report by Hennessy, et al (2004) for the CSIRO and BOM found that between 1950–2003, NSW became 0.9°C warmer, with more hot days/nights and fewer cold days/nights. Annual total rainfall declined by an average of 14 mm per decade, with the largest declines in rainfall near the coast due to an increase in El Niño years since the mid-1970s. Extreme daily rainfall intensity and frequency have also decreased throughout much of the State. It is predicted that the climate will continue to change in the future at an increasingly rapid rate.

The predicted changes in climate have the potential to impact the Boambee/Newports Estuary. The CSIRO and DECCW formerly DECC have produced regional climate change projections for the region under differing greenhouse gas emission scenarios for 2030, 2050 and 2070. Table 2-4 below provides a summary the data as appears for 2030 (CSIRO, 2007), 2050 (DECC, 2008) and 2070 (CSIRO, 2007). The CSIRO (2007) projections for rainfall and temperature were updated by DECC (2008) to adjust for rainfall variability, and it is these figures that have been adopted by the NSW Government.


Table 2-3 Monthly Climatic Conditions for Coffs Harbour (BOM, 2009)

Statistic Element

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov

Dec

Annual Average/ Total

Mean Max Temp (°C)

26.9 26.8 25.9 24 21.4 19.4 18.7 19.7 21.9 23.6 24.9

26.3 23.3

Mean Min Temp (°C)

19.4 19.5 18.1 15.2 11.7 9 7.5 8.2 10.9 13.8 16.1

18.1 14

Mean Rainfall (mm)

183.1

219.5

239.3

176.4

161.5

113.6 73.5 80.3 63 91.2 13

3 141.3

1676.1

0

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25

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Figure 2-1 Mean Maximum and Minimum Temperatures (°C) for Coffs Harbour


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Figure 2-2 Average Monthly Rainfall for Coffs Harbour

Table 2-4 Summary of Climate Variables

Predicted Change Climate Variable

CSIRO (2007) 2030 DECC (2008) 2050 CSIRO (2007) 2070

Temperature Annual Average +0.2 - +1.8ºC1

+1 to +3ºC +0.7 - +5.6ºC1

Summer Rainfall Average -13 to +13 %2 -5 to +5 % -40 to +40 %2

Autumn Rainfall Average -13 to +13 %2 -5 to +5 % -40 to +40 %2

Winter Rainfall Average -13 to +7 %2 -10 to +5 % -40 to + 20 %2

Spring Rainfall Average -20 to +7 %2 -10 to +5 %

-60 to + 20 %2

Extreme Rainfall (1 in 40 year 1-day rainfall)

-10-+5%1 Data not available +5 - +10%1

Number of Fire days Coffs harbour: 5 - 61 10 to 15 Coffs Harbour: 5 - 81

Sea Level Rise Above 1990 base line

+40cm +90cm (by 2100, UNSW data and level adopted by NSW Govt)

1 CSIRO Northern Rivers projections

2 CSIRO NSW projections


2.5 Topography

The topography of Boambee/Newports Creek catchment ranges from a flat coastal floodplain along the coast to relatively steep slopes in the west. The slopes are associated with the eastern foothills of the Great Dividing Range. Altitude ranges from sea level at the mouth of the Estuary up to approximately 400 m Australian Height Datum (AHD) in the upper western slopes of the catchment.

The entire catchment is a combination of three relatively small valleys forming individual catchments of Boambee, Newports and Cordwell Creeks. Each catchment start in the elevated slopes of the western foothills and run eastwards where they combine on the coastal floodplain to form one channel.

2.6 Geology

The regional geology of the Coffs Harbour area consists of a sequence of sedimentary and metamorphic rocks with minor igneous intrusions known as the Coffs Harbour association (Sawtell, 2002). This consists of greywacke, siltstone, mudstone and argillite, with some minor cherts, jaspers and metabasalts (Milford, 1999). The rocks of the Coffs Harbour association are moderately to heavily cleaved, tilted and deformed, and dip regionally to the west/north-west (Milford, 1999). They are typically moderately resistant to weathering, particularly the higher grade metamorphis rocks and the metabasalts, although some minor deep weathering siltstone strata can be found (Milford, 1999).

The Coffs Harbour association can be subdivided into three lithological units that are known as:

Coramba Beds;

Brooklana Beds; and

Moombil Siltstone.

The composition of the units varies with lower grade lithofeldspathic wackes in the north to higher grade black siltstones and argillites in the south (Milford, 1999).

In the Quaternary Period, unconsolidated sediments were deposited in the lower reaches, beach and foredune of the Boambee/Newports Estuary as Holocene alluvial clay, silt, sand and gravel (Milford, 1999). Pleistoncene podzolised barrier and estuarine sands are inland of the Holocene beaches and dunes and date from the last interglacial high sea level. The coastal heath behind Boambee Beach is underlain by these sands and are in turn underlain be mottled grey Pleistocene estuarine clays (Milford, 1999).

2.7 Soils

There are several soil groups associated with the Boambee/Newports Estuary catchment. The characteristics of these soils have been taken from the Soil Landscapes of the Coffs Harbour 1:100,000 Sheet (Milford, 1999) and are summarised in Table 2-5 below. Figure 2-3 shows the location and extent of each of these soil types.


Table 2-5 Soil Summary

Soil Description Limitation

Coffs Creek ‘cc’ Deep to moderately deep, moderately well to poorly drained alluvial soils, podzolic soils and yellow earths.

Minor streambank erosion.

Coffs Harbour ‘cf’ Deep, moderately to poorly drained podzols with sandy acid peats and peaty podzols.

Wind erosion. Rill erosion.

Dairyville ‘da’ Deep, moderately well drained alluvial soils, structured sands and brown earths.

Moderate gully and streambank erosion.

Look-At-Me-Now ‘lo’

Moderately deep to deep, stony, moderately well drained yellow, brown and red podzolic soils.

Rill erosion.

Megan ‘me’ Moderately deep to deep, well drained structured red, brown and yellow earths, brown, red and yellow podzolic soils and krasnozems

Moderate, occasionally high erosion. Gully erosion.

Moonee ‘mo’ Moderately deep to deep, poorly drained humic gleys. Minor to moderately deep gully erosion.

Newport’s Creek ‘np’

Deep, poorly drained podzolic soils and humic gleys. Minor streambank erosion.

Suicide ‘su’ Moderately deep to deep well drained, stony structured yellow earths, lithosols and red earths.

Severe sheet, rill and gully erosion.

Toormina ‘tm’ Deep, poorly drained humic gleys, solonchaks and siliceous sands. Minor to moderate bank erosion.

Ulong ‘ul’ Moderately deep to deep well drained structured red, yellow and brown earths, red and yellow podzolic soils, plus deep well drained krasnozems.

Moderate, occasionally high erosion. Moderately deep, discontinuous gully erosion.

Disturbed Terrain ‘xx’

May include soil, rock, building and waste materials. NA

2.7.1 Acid Sulfate Soils

Holocene estuarine sands, muds and clays containing potential acid sulfate soil (ASS) materials were deposited in the mangrove mud basins and mouth of the numerous creeks along the coast (Milford, 1999). Acid sulfate soils can thus be found in many low-lying coastal swamps in the Estuary.

Acid sulfate soils is the name given to naturally occurring soil and sediment containing iron sulfides. ASS where formed approximately 10,000 years ago when sulfate rich marine water inundated iron rich soils within low lying swamps and wetlands to form pyrite (ASSMAC, 1998). When ASS are exposed to the air, through drainage of coastal areas for flood mitigation, urban expansion or agricultural production, oxidation occurs and sulfuric acid is ultimately produced. The sulfuric acid can drain into waterways and cause severe short and long term socio-economic and environmental impacts. Acid runoff has been the cause of a number of fish kills in some coastal estuaries.

Figure 2-4 shows that a large area of the Boambee/Newports Estuary has ASS.

su

water

cf

me

ul

ul

su

me

cc

np

nn

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me

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pl

BOAMBEE

TOORMINA

COFFS HARBOUR

Figure 2.3


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0 360 720 1,080 1,440180

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LEGEND

o© 2009. While GHD has taken care to ensure the accuracy of this product, GHD and COFFS HARBOUR CITY COUNCIL, DEPARTMENT OF LANDS make no representations or warranties about its accuracy, completeness or suitability for any particular purpose. GHD and COFFS HARBOUR CITY COUNCIL, DEPARTMENTOF LANDS cannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.

Date 25 JUN 2009


Soil Landscapes

Data Source: Coffs Harbour City Council: Aerial - 2006; Coffs Harbour City Council: Catchment Data - 2008; Canri: Acid Sulphate Soils - 2005. Created by: fmackay


1:45,000 (at A4)

Catchments Soil Landscapesbdcc

cfdago

kolome

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plsutm

ulwaterxx

CoffsHarbourAirport

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Figure 2.4


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0 360 720 1,080 1,440180

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LEGEND

o© 2009. While GHD has taken care to ensure the accuracy of this product, GHD and COFFS HARBOUR CITY COUNCIL, DEPARTMENT OF LANDS make no representations or warranties about its accuracy, completeness or suitability for any particular purpose. GHD and COFFS HARBOUR CITY COUNCIL, DEPARTMENTOF LANDS cannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.

Date 29 JUN 2009


Acid Sulfate Soils

Data Source: Coffs Harbour City Council: Aerial - 2006; Coffs Harbour City Council: Catchment Data - 2008; Canri: Acid Sulphate Soils - 2005. Created by: fmackay, Gismodelling


1:45,000 (at A4)

Catchments Acid Sulfate SoilsHigh riskDisturbed soilsLow risk


3. Land Use

Human impacts on estuarine environments are well documented and, in some situations, have resulted in the complete loss of biota (Sawtell, 2002). Human settlement generally results in clearing vegetation, increasing impermeable surfaces, exposing soils and increasing concentrations of nutrients and chemicals.

The DECCW formerly NSW Department of Natural Resources (DNR, 2009) suggests that declining water quality and sedimentation are one of the most serious issues affecting NSW estuaries. It is claimed that elevated nutrients and sedimentation are largely the result of inappropriate catchment land use practices, sewage discharge and urban run off. The DNR go further to explain that rapid population growth and expanding development is affecting estuarine ecosystems.

Sawtell (2002) has identified the human impacts on the creeks in the Coffs Harbour area include, septic tank run-off, sewerage system overflows, stormwater runoff, increased nutrients, pesticides use, sedimentation, clearing and increased runoff.

To gain an understanding of how human settlement has impacted on the Boambee/Newports Estuary, this section explores the past, present and future land uses within the catchment.

3.1 Previous Land Use

Previous indigenous studies provide evidence that the study area was first habited by the Gumbayngirr speaking people. The Gumbaingirr territory traditionally extended over a wide area from the Clarence River to at least as far south as the Nambucca.

The region was first sited by Europeans by Captain James Cook on May 15 1770 and was not settled until the 1800’s. Settlement by Europeans increased in the 1870s to early 1880s, as settlers overflowed from the Bellinger and Clarence River districts (CHCC, 2001).

3.1.1 Primary Production

Following European settlement, land use was dominated by timber cutting, which flourished after the completion of the Coffs Harbour jetty in 1892. With the opening of the railway line much of the land use changed to banana growing which was introduced by Herman Reick circa 1881. The Raleigh to Coffs Harbour section of the North Coast railway was completed in 1915, which increased the banana industry in Coffs Harbour significantly (CHCC, 2001). Banana growing gained further momentum in the 1920's as the plantations in northern Queensland were wiped out by disease. During this time other land uses including fruit growing, dairying, and sugar cane farming were being introduced into the area. However, many of these ventures failed (Visit Coffs Harbour, 2009).

By 1955 Coffs Harbour was considered the major banana producing area in Australia with Sawtell (2002) estimating that in 1954, approximately 262 hectares of land within the Boambee/Newports catchment supported banana plantations. In the late 1960s Coffs Harbour’s banana industry had reached its peak, when NSW produced 80 per cent of the nation’s bananas (CHCC, 2001). During the 1960’s a large proportion of the catchment, mostly to the west of the Pacific

CoffsHarbourAirport

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Figure 3.1


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LEGEND


Date 29 JUN 2009


Banana PlantationAreas 1943-1994



1:45,000 (at A4)

CatchmentsBanana Plantation Areas 1943-1994



© 2009. While GHD has taken care to ensure the accuracy of this product, GHD and COFFS HARBOUR CITY COUNCIL make no representations or warranties about its accuracy, completeness or suitability for any particularpurpose. GHD and COFFS HARBOUR CITY COUNCIL cannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or maybe incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.


Figure 3.2


22-14223

26 JUN 2009

Boambee/Newports Estuary

Date


Historical Images 1942 - 1994

1994

1:40,000Scale

1984

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1967

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G:\22\14223\GIS\Maps\Estuary Management Plan\2214223_EMP_FIG3-2_Historical_Photos_20090624_A.mxd

Data Source: Coffs Harbour City Council: Land Use - 2007. Created by: fmackay, rmholmewood

o


Highway was cleared for banana growing or other agricultural pursuits. Sawtell (2002) estimated that in 1974, approximately 477 hectares in the Boambee/Newports Creek catchment were being cultivated for bananas. The area of the catchment that has been used for growing bananas at some stage between 1943 and 1994 is shown on Figure 3-1.

Over the last 30 years, the banana industry has been in decline with major plantings in Queensland accounting for about 75 per cent of national production. In 1994, Sawtell (2002) estimated the area used for banana plantations had dropped to approximately 414 hectares. The area under bananas in the Coffs Harbour region has continued to decline at about five per cent per annum for the past 10 years (CHCC, 2001).

3.1.2 Urban Development

The aerial photographs in Figure 3-2 show that by 1973, large areas were cleared for residential development especially to the west of Sawtell and south of Coffs Harbour City. Large areas surrounding the Boambee Creek and Newports Creek were cleared in the mid catchment both to the east and west of the Pacific Highway for either agricultural pursuits or residential development. The Coffs Harbour airstrip and racecourse were also major land uses in the catchment by this time.

The assessment undertaken by Sawtell (2002) of settlement patterns between 1954 and 1994 and shown in Figure 3-3, suggests that although urbanisation was increasing in 1974, most of the cleared areas were being used for agriculture.

01020304050607080

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Figure 3-3 Human Settlement Patterns 1954 to 1994 (Sawtell, 2002)

Figure 3-2 shows that by 1984 the majority of remaining vegetation, which surrounded Sawtell was cleared for residential development. During this time, small pockets of vegetation remained directly surrounding Boambee/Newports Estuary to the north of Sawtell. The mid and upper catchment was also largely cleared (on both sides of the Pacific Highway) mostly for agricultural pursuits.

By 1994, Figure 3-2 and Figure 3-3 show that there had been significant growth in the urbanisation of the Boambee/Newports Creek catchment. The large industrial areas in the mid catchment were also developed or being developed during this period. Other developments in the mid-catchment during this period included the university, some recreational areas and the sewage treatment plant.


3.2 Existing Land Use

The surrounding land use of the estuary is highly developed and diverse. Figure 3-4 demonstrates the land uses zones within the catchment and Figure 1-1 shows a recent aerial photograph of the area. The specific land use types include the following:

Urban residential uses;

Rural residential uses;

Industrial land uses (Hopkins Dive and Isle Drive Industrial estate);

Commercial areas (Sawtell town centre);

Existing Pacific Highway;

Environmental protection areas;

Schools;

University;

Aerodrome; and

Primary Production.

Each zone (under the Coffs Harbour Local Environmental Plan 2000) and proportions of land use are shown in Table 3-1. Although Table 3-1 is based on zoned land and not actual use, it is considered a reasonable indication of use because most zoned land within the Coffs Harbour area is fully developed.

Table 3-1 Land Use Proportions with the catchment

Zone Ha Proportion of total Catchment Area (%)

1A Rural Agriculture 1170 23.7%

1B Living Zone 320 6.5%

1F State Forest Zone 506 10.2%

2A Residential Low Density Zone 485 9.8%

2B Residential Medium Density 8 0.2%

2C Residential Medium-High Density 15 0.3%

2E Residential Tourist 16 0.3%

3B Business City Support 7 0.1%

3F Business Neighbourhood 2 0.0%

3G Business Mixed Use 4 0.1%

4A Industrial Zone 265 5.4%

5A Special Uses Zone 622 12.6%

6A Public Recreation Zone 485 9.8%


Zone Ha Proportion of total Catchment Area (%)

6C Private Recreation Zone 64 1.3%

7A Environmental Protection – Habitat and Catchment Zone. 855 17.3%

7B Environmental Protection Scenic Buffer 23 0.5%

LEP 2000 Zones1A, Rural Agriculture1B, Rural Living1F, Rural State Forset2A, Residential Low Density2B, Residential Medium Density2C, Residential Medium-High Density2E, Residential Tourist3B, Business City Support3D, Business Tourist Service Centre3F, Business Neighbourhood3G, Business Mixed Use4A, Industrial5A, Special Uses6A, Open Space Public Recreation6C, Open Space Private Recreation7A, Environmental Protection Habitat & Catchment7B, Environmental Protection Scenic Buffer

Figure 3.4


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0 340 680 1,020 1,360170

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LEGEND


Date 26 JUN 2009


Coffs Harbour LEP 2000Land Use Zones

Data Source: Coffs Harbour City Council: LEP200 Zone & Catchment Data - 2007. Created by: fmackay, tmorton


1:45,000 (at A4)

CatchmentsEstuary


The land use within the catchment can be divided into two separate areas to the west and east of the Pacific Highway.

To the east of the Pacific Highway the land has been largely developed with a mixture of land uses including residential, industrial, public and private recreation, environmental protection area and special uses such as schools, the university and the aerodrome. Only a small proportion of vegetation remains surrounding the Estuary. Land uses in the southern catchment are mostly residential. The mid catchment of Newports Estuary flows through an industrial area before entering a low-lying floodplain with adjacent land uses including a golf course, airport and residential. Some large industrial enterprises are also established in the mid section of Boambee Estuary before entering an area dominated by residential land use.

To the west of the Pacific Highway the majority of the area is currently used for agriculture, rural residential and habitat protection. A proportion of land in this area is used for residential, industrial and private recreation purposes. This area is characterised by large areas cleared for agricultural production (mainly bananas and grazing land), and a mosaic of remnant and regenerating vegetation predominantly along drainage lines and on steep areas.

3.3 Future Land Use

Land use changes are a key pressure affecting aspects of the physical and biological environments of estuaries. If uncontrolled, future development in the catchment may have a significant impact on the Estuary.

3.3.1 Urban Development

The Mid North Regional Strategy (DoP, 2008) and the ‘Our Living City’ Settlement Strategy

(CHCC, 2007) sets out long-term framework for land-use planning in Coffs Harbour. Within these documents the following areas have been identified for future land use changes within the catchment. The location and extent of the proposed land use changes are also shown on Figure 3-5.

North Boambee Valley: The ‘Our Living City’ Settlement Strategy (CHCC, 2007) has identified 84.9 hectares of land as possible residential (north of North Boambee Road) from 2011 and 73.5 hectares as possible industrial (south of North Boambee Road). This area is located adjacent to Newports Creek.

Sawtell/ Toormina/ East Boambee: located to the north of Sawtell along the Pacific Highway. The ‘Our Living City’ Settlement Strategy (CHCC, 2007) has identified 47.7 hectares of land as possible residential for 477 dwellings. This area is located adjacent to Boambee Creek.

West Boambee: located west of the Pacific Highway. The ‘Our Living City’ Settlement Strategy (CHCC, 2007) has identified 46 hectares of land as possible rural residential for 23 rural residential dwellings.

Whilst no quantitative assessment has been undertaken of the impact of future development on the Boambee/Newports Estuary, it is important to note that all new development is controlled by State and Local Government development controls that aim to protect environmental resources.


3.3.2 RTA Preferred Pacific Highway Bypass Route

CHCC at its meeting on the 17 May 2007 recommended to incorporate the Coffs Harbour Pacific Highway Planning Strategy into any future plans. The preferred route for the Coffs Harbour Highway Planning Strategy was announced in December 2004. The preferred route (inner south 1), shown on Figure 3-5, is proposed to be located within the Boambee/Newport Creek catchment.

On the 23 September 2008, the RTA announced the concept design for the Coffs Harbour bypass, which includes a four-lane duel carriageway from Englands Road to Korora Hill. This will have significant impacts on the middle and upper catchment to the west of the existing Pacific Highway.

Figure 3.5G:\22\14223\GIS\Maps\Estuary Management Plan\2214223_EMP_FIG3-5_Land_Use_20090626_A.mxd

0 470 940 1,410 1,880235

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LEGEND



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Date 26 JUN 2009oCoffs Harbour City CouncilBoambee / Newports Estuary

Future Land Use andPacific Highway Bypass Route

Data Source: Coffs Harbour City Council: Land Use - 2007. Created by: fmackay, tmorton




1:63,000 (at A4)

Catchments


4. Geomorphology

4.1 Introduction

This section provides an assessment of the geomorphological character and behaviour of the Boambee/Newports Estuary largely based on:

A site inspection conducted on the 16th of April 2009;

Review of existing relevant information; and

Interpretation of morphological changes of the entrance from historical aerial photography and gauged flow data.

4.2 Overview of the Geomorphology of the Boambee/Newports Estuary

From records it appears that the estuary mouth has been permanently open to the ocean for many decades due to a high fluvial influence. However, the estuary entrance is considered to have the potential to close should lengthy periods occur with reduced rainfall and flooding events. The estuary therefore can be considered to be an Intermittently Closed and Open Lake or Lagoon (ICOLL) and falls under the wave-dominated barrier estuary classification (Haines et al., 2006). An ICOLL is usually characterised as a river or creek that is directly connected to the ocean by a channel that is typically flanked by floodplain vegetation and swamps.

ICOLLs and coastal creeks are narrow, generally shallow water bodies that develop on prograding coastal sequences formed from beach ridges, dunes and barriers. The catchment for ICOLLs is limited to the immediate surrounding hinterland. The Boambee/Newports Estuary has no artificial entrance training works as Boambee Headland naturally trains it on the southern side. To the north the estuary barrier exists due to the creek delivering sediment faster than the waves can disperse it resulting in a tendency for the coastline to build up and form a coastal protrusion. High wave energy results in the distribution of sediment along the coast forming the Boambee barrier. Fluvial input is the variable factor in determining a wave dominated estuaries final morphology and functioning.

Seasonal and climatic factors dictate the functions of estuaries due to periodic high-flow events causing flushing, sedimentation, and erosion of the main channel and floodplain. Boambee/Newports Estuary exhibits periodical high-energy flows causing scouring and bank erosion and occurring frequently enough to maintain an open entrance. Sediment deposits at and just upstream of the entrance appears relatively stable where marine derived sands are constantly being reworked with little net movement in or out of the Estuary.

The rate of estuary infill is determined by the morphology of the estuary, the volume of fluvial sediment input and the influence of waves and tides on the estuary. The dominant factor for estuary infilling and the volume of fluvial sediment supply is directly related to the catchment area, rainfall and river discharge which is in turn influenced by the lithology and weathering processes operating within the catchment (Sloss, 2001).


4.2.1 Geomorphic Process Zones of the Boambee/Newports Estuary

Estuarine geomorphology is largely controlled by the energy in the system, either from tides or fluvial influences. Tripartite zonation of estuaries has been shown to be a common feature in wave-dominated estuaries along the NSW coast (Nichol, 1991; Kench, 1999; Roy et al., 2001). The same is the case for the Boambee/Newports Estuary with three zones that relate to its depositional environment and sediment availability (Nichol 1991). These three zones, shown in Figure 4-1, are the fluvial delta zone, a central mud basin and the marine dominated estuary mouth (Nichol, 1991; Kench, 1999). Processes and energy in each of the zones varies, creating different depositional features.

Fluvial deltas are found at the landward margin of the estuary and are largely described as the most complex of the facies divisions within the estuarine systems (Kench, 1999). This zone contains the most diverse sub-environments including river and distributary channel beds, mid-channel shoals and bars, levee banks and crevasse splays, freshwater and brackish swamps, and flood plains (Kench, 1999). The type of sediment found in these deposits depends on the river energy and the bedrock lithology and weathering (Roy, 1994) but is typically composed of poorly sorted sand, mud and some organic matter that have been re-worked by the river and the prograding delta. The general channel width of the Boambee estuary in the fluvial delta zone varies between 10 m at the upper tidal limit to up to 70 m on large bends in the channel. The total length of the fluvial zone over the 3 inlets (Newports, Boambee and Cordwells Creeks) is approximately 3.79 km.

The sediment trapping efficiency of wave-dominated estuaries is very high because sediment from the catchment and marine sources is trapped in the low-energy central basin, which may capture up to 80% of fine sediment (Roy et al., 2001). Central mud basins generally have larger relative water depths than the other estuarine zones. This creates a decrease in energy in the environment, enabling the fine mud and silt to settle out from suspension (Kench, 1999). General channel width in the Boambee/Newports Estuary central mud basin varies between 50 m to 150 m. This is more than twice as wide as the fluvial zone channel, with length also being much longer at 7.12 km.

The marine dominated estuary mouth is a high-energy environment at the seaward edge of the estuary, where coarse sands are deposited by tidal currents and waves (Kench, 1999). This zone contains the coastal sand barrier that plays an important role in the evolution of estuaries. This facies also includes the marine flood-ebb delta that can progressively bring sand into the mouth of the estuary (Roy et al., 2001). Along with the central mud basin, sediment deposits in the Boambee/Newports Estuary are also substantial in the marine zone where a constant reworking of sediment is occurring. Reworking of sediment occurs by the incoming and outgoing tidal flows and the occasional flood event.

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Figure 4.1


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Catchment Characteristics& Geomorphic Zones



1:45,000 (at A4)

Catchments DIPNR SiteEstuary Transition Zone


The marine zone extends from the confluence of Boambee Creek and Newports Creek downstream to where the Estuary meets the ocean and is approximately 3.18 km in length. Channel width is generally between 150 m and 200 m upstream of the railway bridge. However, the channel is constricted to less than 60 m around the mouth due to bedrock constraints on the southern side and the beach barrier dune system on the northern side. The rail bridge and rail embankment to the north also adds to this natural constriction, allowing water exiting the estuary to pool upstream during flood flow events. This combined with the greater channel width upstream creates a large area susceptible to deposition.

It is understood that parts of the estuary adjacent to the recreational area and barbeques has been dredged in the past with a backhoe. This dredging has been done primarily for the benefit of swimmers to create areas of more depth. The works are minor enough and localised enough to not have a great effect on the processes of the estuary.

4.2.2 Estuary Areas, Depths and Volumes

Table 4-1 provides information on estuary catchment areas, estuary waterway areas, estuary depths and volumes. The estuary volumes are based on field observations of water depth and measurements of surface areas from aerial photography.

Table 4-1 Catchment Data

Estuary Catchment Area (km2)

Estuary Area (m2)

Adopted Estuary Depth (m)

Estuary Volume (m3)

Newports 27.94 209,221 1.75 366,136

Boambee 12.98 561,614 1.5 842,421

Cordwells 8.44 31,798 1.25 39,747

Total 49.36 802,633 N/A 1,248,304

4.2.3 Sediment Transport Processes

Boambee Creek Estuary Tidal Data obtained from DECCW formerly DIPNR – Manly Hydraulics Laboratory was used to infer the flow regime of the estuary under ebb and flood tides. Data was measured in May 2005 of typical maximum velocities at peak discharge using an RD Instruments Workhorse Acoustic Doppler Current Profiler (ADCP). The average maximum velocity results are displayed in Table 4-2 for three sites within the estuary. These locations are displayed in Figure 4-1.


Table 4-2 Tidal Velocities – Average Maximums

Velocity (m/s) DIPNR Site

Ebb Flood

2 0.64 0.80

4 0.36 0.46

5 0.28 0.40

While the influence of waves declines quickly adjacent to the entrance of the mouth, there is still some substantial tidal movement that is occurring in the Boambee/Newports Estuary due to its relatively deep and open entrance. River influence does naturally become dominant further inland as tides are attenuated into channels. The higher velocities, which are seen for the flood tide, indicate that tidal sediment transport processes are likely to result in a net movement of sediment upstream. The ebb tide is between 70 % and 80 % of the velocity of the flood tide even at DECCW formerly DIPNR Site 5 which exists over 3 km upstream from the estuary mouth.

However, any net upstream transport by tidal processes is likely to be countered by the downstream transport of sediment during flood events. Therefore, there is a limited net change in the fluvial marine zone due to flushing by flood events. Upstream within the central mud basin and the fluvial zones, the narrower channel allows sediment to be transported longitudinally downstream and laterally onto floodplains during flood events.

The marine zone however has a wider channel that results in a reduced capacity for flood and tidal flows to transport sediment. Hence, there are significant in channel sediment deposits here in the form of sand bars. Further still, as discussed previously, flows are constricted by the rail bridge and embankment. This creates a tendency for large flows to back up and for flow velocities to reduce upstream, generating an area of high sediment deposition potential. The greatest depth in the Estuary is located in the vicinity of the railway crossing, where the channel constriction maximises the scouring effects of flood and tidal flows. This increased scour potential in conjunction with the influence of the bedrock headland at the mouth are considered the main factors that maintain a consistently open estuary entrance.

The upper fluvial zone of the Estuary contains a bed load of gravel/sand that is being sourced from some noticeably impacted areas in the upper catchment (see Section 4.3.1). This was noticed particularly in the upper reaches of Cordwells Creek and Boambee Creek.

Sediment size information obtained from Sawtell (2002) shows sediment sampled from the estuarine floor at locations in the marine zone consist of fine sand while samples from the central mud basin within the lower section of Newports Estuary consist of very fine sand. This indicates that sediment size reduces upstream from the entrance. This upstream reduction in sediment size is considered to be a result of the associated upstream decrease in tidal flow velocities.


4.3 Site Assessment

A site assessment of the estuary was undertaken on 15th of April 2009. The primary focus of this assessment was to identify and map the stability of banks within the Estuary. Identified bank erosion was assessed based on the level of activity as described in Table 4-3 below and other characteristics such as whether the bank is composed of bedrock or has mangrove flats fronting it. GPS co-ordinates for each erosion site were taken for subsequent GIS mapping.

Table 4-3 Erosion Categories and Description

Erosion Category Description

Stable Banks are stable and are generally well vegetated, composed of bedrock or have been stabilised artificially.

Minimally Active Banks display minor, localised erosion or evidence of past erosion. Generally active only in high to extreme flow events.

Moderately Active Banks exhibit minor to moderately severe erosion over lengths greater than 5 metres. Generally active in moderate to high flow events.

Highly Active Banks exhibit moderate to severe erosion over lengths greater than 5 metres. Generally active over all flow events.

The results of the bank stability assessment are displayed in Figure 4-2 to Figure 4-4 and are summarised below:

The banks are stable along 34.8 % of the length of the estuary or approximately 10.5 km;

The banks are minimally active along 28.6 % of the length of the estuary or approximately 8.6 km.;

11.1 % or 3.4 km of the banks are moderately active; and

1.7 % is made up of the active beach environment and the estuary mouth.

No highly active banks were observed however, 23.8 % or 7.2 km of the estuarine banks could not be accessed during the field investigation nor could be seen via analysis of the aerial photographs due to the vegetation cover but is believed to be largely minimally active to stable.

Review of the stability mapping outputs against aerial imagery indicates that there is not any direct correlation between bank stability condition and land use or riparian zone width.

There are no obvious historical changes in the position of banks in any part of the estuary (see Section 4.4). The minimally active zones are only minor bank erosion, which is considered natural. The moderately active zones are localised and are generally not directly caused by human access or activities. However, a few situations, especially in the marine zone, bank stability is influenced by informal bank access for recreational activities such as fishing etc. This access is having an impact on the banks and fringing vegetation and should be limited as much as possible.

!

Upper Boambee Creek:gravel deposits on mud flatsfrom recent flood activity

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Cordwells Creek:moderately active left bank

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Cordwells Creek:upstream view of moderatelyactive right bank

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Middle Boambee Creek:upstream view of right bank,large woody debry and bankdisturbance from access bypeople

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Middle Boambee Creek:downstream view ofmoderately active left bank

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Upper Boambee Creek:weir structure

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Upper Boambee Creek:minimally active leftbank erosion

!

Middle Boambee Creek:upstream view of stableright bank

PACIFIC

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Figure 4.2


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0 90 180 270 36045

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Date 26 JUN 2009


Bank StabilityCordwells / Upper Boambee Creek

Data Source: Coffs Harbour City Council: Aerial - 2006; Coffs Harbour City Council: Catchment Data - 2008. Created by: fmackay, tmorton


1:12,000 (at A4)

Catchments

Bank Stability ConditionStableStable Bedrock BankStable to Minimally ActiveMinimally ActiveMinimally to Moderately ActiveModerately ActiveDid Not AccessStable Mangrove Mud Flats

!

Newports Creek:minimally active

!

Newports Creek:erosion due to informalbank access

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Newports Creek:upstream view of sand bank

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Newports Creek:upstream view ofminimally active right bank

!

Newports Creek:moderately activeleft bank erosion

PACI

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Figure 4.3G:\22\14223\GIS\Maps\Estuary Management Plan\2214223_EMP_FIG4-3_NewportsCk_20090624_A.mxd

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22-14223


Bank StabilityNewports Creek

Data Source: Coffs Harbour City Council: Land Use - 2007. Created by: fmackay, rmholmewood, tmorton




1:12,000 (at A4)

Catchments Bank Stability Condition

Stable

Stable to Minimally Active

Minimally Active

Minimally to Moderately Active

Moderately Active

Stable with Localised Failures, Low Banks

Stable Mangrove Mud Flats

Did Not Access

!

Lower Boambee Creek:downstream view ofsand bank !

Lower Boambee Creek:sand flats showingdesposition due torecent flooding

!

Lower Boambee Creek:right bank showingbedrock base

!

Lower Boambee Creek:downstream view ofsand bank

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Lower Boambee Creek:upstream view of sand bank

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Lower Boambee Creek:erosion due to informalaccess

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Lower Boambee Creek:downstream view frombridge towards estuarymouth, bedrock banks

TOORMINA

Figure 4.4G:\22\14223\GIS\Maps\Estuary Management Plan\2214223_EMP_FIG4-4_LwrBoambeeCk_20090624_A.mxd

0 80 160 240 32040

Metres

LEGEND



22-14223


Bank StabilityLower Boambee Creek

Data Source: Coffs Harbour City Council: Land Use - 2007. Created by: fmackay, rmholmewood, tmorton




1:12,000 (at A4)

Catchments Bank Stability Condition

Stable Bedrock Bank

Stable to Minimally Active

Minimally Active

Minimally to Moderately Active

Moderately Active

Active Beach Environment

Erosion due to Informal Access

Estuary Mouth

Stable Mangrove Mud Flats

Did Not Access


4.4 Upper Catchment

In addition to the assessment of Estuary bank erosion, a preliminary assessment of stream stability was undertaken along streamlines in the upstream catchments. It should be noted that these inspections were undertaken following flow events that occurred in March 2009 which were reportedly greater than the 1 in 100 AEP. As a result, the site inspection identified several areas of significant channel and slope instability in the upstream catchments, as shown in Figures 4-5 and 4-6. Such areas are a substantial source of sediment to the downstream reaches of the creek and the Estuary itself.

Historically, the natural cover of the catchment has been up to 70% cleared, mostly to accommodate banana plantations and dairy farming. As a result, vegetation coverage within the immediate riparian zone is minimal to non-existent. Hence, there are limited controls on upstream channel stability and sediment transport capability. The upstream catchment, therefore, is a significant sediment source and has high capacity to deliver sediments to the Estuary.

Based on these observations, it is inferred that the gravel deposits identified in the middle to upstream extents of the Estuary fluvial zone are of post-European origins as a result of upstream catchment disturbances. These gravel deposits may be progressing further downstream with each major flow event, altering channel substrate and potentially impacting upon benthic ecological processes.

Future development of North Boambee valley is expected to continue and several impacts are likely to result in this including more exposed soil, less permeable surfaces such as roads and flow convergences increasing volume and velocity of water runoff.

Figure 4-5 Upstream view of Boambee Creek gravel deposits


Figure 4-6 Upstream view of large gravel deposit on a tributary of Cordwells Creek

4.5 Historical Analysis

A total of six (6) historical aerial images covering the period from April 1942 to May 1994 were acquired. This process allows images to be spatially overlain so that relative changes in the size and position of landform features can be determined. Due to different image extents, this analysis has been largely limited to the marine zone of the Estuary, where coverage was available over all images assessed.

Analysis of the images indicates that while some general changes have occurred in the morphological characteristics of the sand bars within the marine zone, there has been little change with respect to channel width and bank location. This indicates that the Estuary has been relatively stable for the period of time between the earliest and latest aerial images. The differences observed in each image in comparison to the most recent image (2007) are summarised in Table 4-4. The locations of sites referred to in Table 4-4 are displayed in Figure 4-1. In addition, Table 4-4 provides a consideration of the recent preceding flow history inferred from Bureau of Meteorology rainfall data. The historical images are displayed in Figure 3-2.

4.6 Climate Change Impacts on Geomorphology

The ultimate control on estuary evolution is sea level (Kench, 1999; Zaitlin et` al., 1995). Much like past sea levels have determined the shape and depth of the incised valleys and barrier evolution so will future sea levels (Dalrymple et. al. 1992; Roy, 1994). This inevitably determines the morphology of the Estuary and its processes. Climate change is predicted to increase sea levels that will result in higher tidal levels and greater tidal volume leading to an increase in the level and frequency at which processes that contribute to erosion will operate on the bank. Additionally, more frequent inundation of vegetation colonising the lower elevated sections of the bank may result in


changes to vegetation types and exposure of sediments to erosion processes. Hence, sea-level rise is likely to exacerbate bank erosion through larger and more regular flooding, especially along those sections identified as being moderately active. Additionally climate change is predicted to result in greater variability in rainfall events in eastern Australia meaning that periods of altered rainfall are likely to occur. Rainfall is likely to become less frequent but of greater intensity and of longer duration. This will result in an altered sedimentation process and may alter entrance morphology. The latter may also be influenced by changes in rates of littoral sand transport as beaches recede and supply sediment to the littoral zone and through changes in storm intensity and frequency. Given the unknowns surrounding the level and direction of change in these effects, the likely impact on the Estuary entrance cannot be defined.

4.7 Summary and Recommendations

The Boambee/Newports Estuary in respect to its geomorphic form is in general good condition. Banks are largely stable to minimally active and the general form of the estuary has remained more or less unchanged over the period of record covered by historical aerial imagery. The shoaling patterns within the marine zone have also remained relatively stable over the last 65 years, with no significant net increase or decrease in bar extents.

Upper catchment processes have improved as areas of banana plantations have decreased however development has increased which may lead to an altered run-off regime. As mentioned previously, the effects of climate change are likely to increase the rate of bank erosion.


5. Hydrology

5.1 Introduction

The freshwater input to the catchment is highly variable and typically there are large floods following significant rainfall events and then a reduced flow sourced form groundwater and seepage from the soils. The climate in Coffs Harbour area, refer Section 2.4, is seasonal with an increase in late summer and early autumn rainfall and reduced winter and spring rainfall and hence the freshwater inflow to the estuary varies seasonally. Floods and high runoff events can result in inundation of the adjacent wetlands. This influx of fresh water supports the wetland ecosystem and is either taken up by the vegetation or evaporates. WDDs are usually prone to flooding due to high freshwater input and low total volume (Ryan et al 2003).

Flow rates through the estuary result from a combination of the tide and the fresh water inflow. During low fresh water inflows the currents in the estuary are relatively modest. During flood flows the channel currents are typically strong due to their small estuary volume, relatively narrow estuary and short residence time of water. Because of this small volume and high flow, floods may completely force saline waters out of the estuary.

The entrance of the delta is penetrated by a salt wedge of denser marine saline waters but is generally characterised by limited tidal intrusion due to the effects of friction and the high river flow. The distance that the salt wedge penetrates depends on the tidal range and the amount of flow received. During seasonal flood events fresh water pushes the salt water intrusion seaward, completely removing the saline environment for a period (Ryan et al 2003). The exchange of fresh and salt water depends on the width of the mouth of the channel. The outflow of catchment river water typically exceeds the inflow of salt water (Ryan et al 2003).

Evaporation is a minor factor in the processes of a WDD due to the relatively low surface area of the delta and usually does not exceed river input (Ryan et al 2003).

5.2 Hydrology Study Methodology

The methodology adopted for the hydrologic assessment has included a combination of completing a literature review, liaising with consultants engaged by CHCC to undertake a flood study for the subject area and completion of MUSIC water yield modelling.

For this assessment we obtained hydrologic results from CHCC’s consultant so that there was not the potential for concurrent CHCC studies to provide differing event hydrologic results.

The MUSIC modelling was completed to quantify the likely increase in catchment water yield that would occur without the implementation of mitigation measures.

5.3 Description of Existing Hydrology

Several of the significant historical rainfalls over the catchment have exhibited a significant rainfall gradient with the rainfall toward the western end of the catchment being significantly greater than


the rainfall recorded near the eastern end of the catchment at the Coffs Harbour Airport. This rainfall gradient does complicate hydrologic analyses for the catchment.

The study area has experienced several rainfall events and floods in the last couple of decades that have reportedly exceeded the current estimate of the 100 year ARI magnitude. Hence, CHCC has responded to this by establishing an appropriate minimum floor level that considers this local flooding characteristic.

Surface runoff in the Coffs Harbour regional area is more then double the average for coastal NSW and almost nine times the average in NSW (CHCC USMP, 2000). High surface runoff volumes in the Coffs Harbour region are attributed to the topography of the regional area, which is characterised by a narrow coastal plain bordered by coastal ranges. Slopes of the coastal range are often greater than 30% and therefore contribute to greater runoff volumes (CHCC USMP, 2000).

The creek system around Coffs Harbour consists of numerous small creek systems. This is resultant of the close proximity of the north-south coastal range to the ocean and smaller ridges extending from the main range towards the coast (CHCC USMP, 2000).

Flood Events

The flood discharges from the mouth of Boambee Creek for a number of Average Recurrence Intervals (ARI) were predicted using the probabilistic rational method by CHCC (CHCC USMP, 2000). The estimated flood magnitudes are presented in Table 6-1.

Table 5-1 Estimated flood discharges at the mouth of Boambee Creek (CHCC USMP, 2000)

ARI (yrs) Discharge (m3/s)

1 136

2 215

5 326

10 405

20 506

50 593

100 693

The results given above indicate that the critical duration 100 year ARI flow is approximately 5 times the magnitude of the 1 year ARI flow rate.

WMA Water is currently undertaking detailed investigations into the hydrology and hydraulics of the Boambee/Newports Creek catchment. The final results from this study are not yet available but should be referred to in subsequent studies on the Boambee/Newports Creek Estuary. Results from this study currently available indicate that:

100 year ARI flow rate upstream of Pacific Highway on Newports Creek – 170 m3/s;

100 year ARI flow rate upstream of Pacific Highway on Boambee Creek – 145 m3/s;


100 year ARI flow rate upstream of Pacific Highway on Englands Road/Marshalls Estate Tributary – 72 m3/s;

100 year ARI flow rate upstream of Hogbin Drive on Newports Creek – 130 m3/s;

100 year ARI flow rate upstream of Hogbin Drive, Marshalls Estate – 24 m3/s.

These flows show a significant flow attenuation in the estuarine area. It is expected this is due to the levelling out of the surrounding topography and the increase in the cross-sectional area the further down the estuary the water travels.

Water Yield

A MUSIC analysis was performed as a part of this study using 20 years of data from 1973. The MUSIC analysis estimated that the average annual water yield for the Boambee/Newports catchment was 46 GL/year for the current land use conditions from the entire catchment area. The water yield results were compared to data presented in Fletcher (2004) “Stormwater Flow and Quality and the Effectiveness of Non-Proprietary Stormwater Treatment Measures”. For the annual rainfall and percentage impervious area of the Boambee/Newports catchment the MUSIC model produces reasonable results compared to the data in Fletcher (2004).

It is expected that the annual water yield from the catchment would have increased over the past decades as the area has been cleared and then developed. This may have resulted in an increase in the volume and velocity of water flowing through the estuary which may have impacted on the estuarine geomorphology and ecology.

More details on the MUSIC analysis are given in Section 7 of this report.

5.4 Predicted Future Hydrology

Flood Events

CHCC has a policy of requiring the provision of detention associated with significant urban development. A detention strategy has previously been developed for the West Boambee area and implementation of this strategy, or an alternate, would achieve a condition of no increase in peak flood flows as a result of future development in West Boambee.

Water Yield

The water yield allowing for development of West Boambee was assessed using the MUSIC model after allowing for changes in the catchment impervious area. There was predicted to be an increase in the annual average catchment yield from 46 GL/year to 54 GL/year should the same annual rainfall pattern be reproduced.

Climate Change Impacts

The North Coast regional climate change projections produced by the CSIRO and DECCW indicate that average annual runoff and stream flow is likely to slightly increase. Summer and autumn runoff depths are likely to increase by 2050, varying from current averages by +4 to +15% and –12 to +16% respectively. Short and intense rainfall events are also predicted to increase.


Increased runoff may have the impact of increasing catchment erosion and thereby increasing sediment loads into the estuary. More sediment in the estuary may lead to silting up of the entrance of the estuary and reduce flushing resulting in stagnant water.

Winter and spring runoff depths are likely to decrease by 2050, varying from current averages by –20 to +8% and –14 to +4% respectively (DECC, 2008).

5.5 Hydrology Summary

The hydrologic analysis indicates that it is not expected that there would be an increase in the peak rates of surface runoff as a result of future development within the study area. WMAwater are in the process of completing a flood study for the area and this will define the existing flooding regime. Results available from that study indicate a flow attenuation through the estuarine area as would be expected given the more level topography and larger cross-sectional area.

The results of the predictions indicate that there will be an increase in the annual water yield with further planned development within the catchment without the implementation of specific measures to mitigate that change in yield. It is expected that there has also been a gradual increase in yield in the past due to the development of the catchment and this is likely to have affected the estuarine geomorphology and ecology.


6. Hydraulics

6.1 Introduction

The hydraulics of the Boambee/Newports Estuary is governed by two influences – the local catchment runoff and the estuarine processes and ocean levels. Both these processes are considered in this assessment.

6.2 Hydraulics Study Methodology

The findings of this section are largely built upon the concurrent flood study being completed by WMAwater for the Boambee and Newports estuarine area.

6.3 Description of Existing Hydraulics

The hydraulic processes in the estuary are characterised by the semi-diurnal ocean tide in conjunction with hydrologic surface runoff contributed by the Boambee/Newports Creek catchment. A semi-diurnal tide is characterised by two high waters and two low waters daily. There is a difference in the water level achieved by each high water during the daily cycle. These water levels are known as higher high water and lower high water. Similarly, there is a difference in the low water levels during the daily cycle and these are known as higher low water and lower low water.

In addition to the daily tidal cycle, tidal range also varies on a fortnightly cycle. For one week the tidal levels approach a maximum level (spring tides) and in the following week the tidal levels approach a minimum (neap tides). As part of the DECCW formerly NSW DIPNR’s Estuary Management Plan, Manly Hydraulics Laboratory (MHL) conducted a data collection exercise to enable an understanding of the tidal processes occurring within Boambee/Newports Estuary. One component of the data collection exercise was the monitoring of water levels at six sites throughout the estuary from 27 April to 4 August 2005. The locations of the water level monitoring sites are shown in Appendix A.

The water level data was subsequently analysed by MHL and the tidal planes were determined. The tidal planes determined include:

HHW (SS) – Higher High Water (Spring Solstices) - The highest of the high waters (or single high water) of any specified tidal day due to the declination in the effects of the Moon and Sun.

MHWS – Mean High Water Springs - Long term average of the heights of two successive high waters during those periods of 24 hours (approximately once a fortnight) when the range of tide is greatest, at full and new moon.

MHW – Mean High Water - A tidal datum. The average of all the high water heights observed over the National Tidal Datum Epoch. For stations with shorter series, simultaneous observational comparisons are made with a control tide station in order to derive the equivalent datum.


MHWN – Mean High Water Neaps - The average throughout a year of the heights of two successive high waters when the range of tide is the least, at the time of first and last quarter of the moon.

MTL – Mean Tide Level. The mean surface elevation determined by averaging the heights of the water at equal intervals of time, usually hourly. Mean water level is used in areas of little or no range in tide.

MLWN – Mean Low Water Neaps - The long term average value of two successive low waters over the same periods as defined for MHWN.

MLW – Mean Low Water - A tidal level. The average of all low waters observed over a sufficiently long period (preferably over the national tidal datum epoch). For stations with shorter series, simultaneous observational comparisons are made with a control tide station in order to derive the equivalent datum.

MLWS – Mean Low Water Springs - A tidal datum. Frequently abbreviated spring low water. The arithmetic mean of the low water heights occurring at the time of spring tides observed over the National Tidal Datum Epoch. It is usually derived by taking an elevation depressed below the half-tide level by an amount equal to one-half the spring range of tide, necessary corrections being applied to reduce the result to a mean value.

ISLW – Indian Spring Low Water - A datum originated by Professor G. H. Darwin when investigating the tides of India. It is an elevation depressed below mean sea level by an amount equal to the sum of the amplitudes of the harmonic constituents M2, S2, K1, and O1.

Figure 6-1 provides a graphical representation of the tidal plans described above.

Higher High Water (Spring Solstices)

Mean High Water Springs

Mean High Water

Mean High Water Neaps

Mean Tide Level

Mean Low Water Neaps

Mean Low Water

Mean Low Water Springs

Indian Spring Low Water

Figure 6-1 Semi Diurnal Tidal Planes

The tidal planes determined by MHL for Newports Creek, Boambee Creek and Cordwells Creek are presented in Table 6-1.

http://www.mhl.nsw.gov.au/www/tide_glossary.htmlx#M2�

http://www.mhl.nsw.gov.au/www/tide_glossary.htmlx#S2�

http://www.mhl.nsw.gov.au/www/tide_glossary.htmlx#K1�

http://www.mhl.nsw.gov.au/www/tide_glossary.htmlx#O1�


Table 6-1 Estimated Tidal Levels in Estuary (MHL, 2005)

Boambee Creek Newports Creek Cordwells Creek Tidal Planes Ocean

Site 0

(m AHD)

Site 3

(m AHD)

Site 8

(m AHD)

Site 9

(m AHD)

Site 6

(m AHD)

Site 7

(m AHD)

Site 10

(m AHD)

HHW(SS) 1.083 1.001 0.893 0.952 0.903 0.851 0.925

MHWS 0.689 0.667 0.572 0.632 0.563 0.558 0.604

MHW 0.551 0.588 0.515 0.575 0.522 0.515 0.552

MHWN 0.414 0.509 0.458 0.517 0.482 0.473 0.499

MTL 0.017 0.259 0.249 0.306 0.269 0.289 0.287

MLWN -0.379 0.008 0.041 0.095 0.055 0.105 0.075

MLW -0.517 -0.071 -0.016 0.038 0.015 0.062 0.022

MLWS -0.654 -0.149 -0.073 -0.020 -0.025 0.020 -0.031

ISLW -0.936 -0.388 -0.302 -0.248 -0.268 -0.190 -0.260

The tidal range in the estuary is largest at the mouth and reduces upstream to the tidal limits. The mean tidal range at the Coffs Harbour ocean monitoring site is 1.068m. This reduces to 0.659m 500m upstream of the mouth of the estuary and 0.453m approximately 8km upstream in Newports Creek. The tidal regime of the estuary is dependent upon the condition of the entrance. The more scoured the entrance, the lower the low tide levels within the estuary and the greater the tidal range. The more shoaled the entrance, the higher the low tide level and the smaller the tidal range.

The Mean Tidal Levels in the estuary, as presented in Table 7-1 above, are greater than the ocean mean tidal levels.

Tidal water levels experienced throughout the estuary reduce in amplitude with distance from the estuary mouth, ceasing upstream at the tidal limit. The tidal limits for the Boambee/Newports Estuary were determined by MHL in work for DECCW formerly NSW DIPNR’s Estuary Management Plan in June 1998. The locations of these tidal limits in the estuary are presented in Table 2-2.

6.3.1 Timing of Tides

Monitoring of the water levels throughout the estuary also enabled a comparison of the timing of spring and neap tides of the estuary with the ocean tide at Coffs Harbour. The lag time between high or low tide in the ocean and high or low tide inside the estuary increases with distance upstream from the estuary’s mouth. At Site 3, just upstream of the mouth of the estuary the average lag time of high and low water tides is 51 minutes while the furthest monitoring location, Site 7, has an average lag time of 131 minutes (see Appendix A for site locations). The lag times within the estuary are also dependant on entrance conditions, as explained above.

The low water springs and neaps in the Boambee/Newports Creek Estuary have a greater lag time than the high water springs and neaps and to a lesser magnitude, spring tides have a greater lag than neap tides.


6.3.2 Velocities

To further investigate the hydraulics of the estuary, MHL also conducted an intensive monitoring program whereby the tidal velocities at three sites in the estuary were monitored over a spring, ebb-flood semi-diurnal tidal cycle (MHL, 2005). The intensive monitoring exercise was undertaken on 5 May 2005. The locations of the monitoring sites are presented in Appendix A. The typical maximum velocities recorded during the monitoring exercise for the ebb and flood stages of the tidal cycle are presented in Table 6-2.

This shows the closer the site was to the entrance, the greater the maximum velocities during ebb and flood tides experienced. Velocities would also be influenced by catchment inputs, with velocities expected to increase following rainfall events. Velocities within the estuary after rainfall may have increased over time as the catchment has been cleared and developed because of the increased area of impervious surfaces.

Table 6-2 Maximum Velocities at Peak Discharge (MHL, 2005)

Site Ebb Flood

Velocity (m/s)

Distance from Left Bank (m)

Depth (m)

Velocity (m/s)

Distance from Left Bank (m)

Depth (m)

2 0.64 18 0.9 0.8 30 1.4

4 0.36 18 0.9 0.46 32 0.9

5 0.28 32 1.9 0.40 10 0.9

6.3.3 Discharge

The intensive monitoring exercise also allowed the determination of typical discharge of the estuary at three locations during the ebb and flood stages of the tidal cycle. The tidal prisms determined by MHL are presented in Table 6-3.

Again, as would be expected, the closer to the entrance the site is, the greater the volume of water being discharged. Entrance conditions, rainfall and development would also influence discharge volumes, as explained earlier.

Table 6-3 Tidal Prisms for Boambee/Newports Estuary (MHL, 2005)

Site Site Name Ebb (m3 x 106)

Flood (m3 x 106)

2 Boambee Creek Entrance 0.52 0.56

4 Boambe e Creek 0.36 0.34

5 Ne wports Creek 0.17 0.17


6.3.4 Flooding Conditions

As indicated in Section 5, WMAwater are undertaking a flood study for the estuary. The hydraulic analysis aspects of the study comprise a MIKE 11 analysis for the upstream reaches and a TUFLOW analysis for the flatter downstream areas.

Results of the analysis have shown that:

The 100 year ARI flood level at the railway line crossing of Boambee Creek is approximately 2.6 m AHD;

The 100 year ARI flood level near the Hogbin Drive crossing of Newports Creek is approximately 2.9 m AHD;

The 100 year ARI flood level at the Hogbin Drive crossing of Boambee Creek is approximately 2.8 m AHD;

The 100 year ARI flood level at the Sawtell Road crossing of Boambee Creek is approximately 3.3 m AHD;

The 100 year ARI flood level at the Pacific Highway crossing of Newports Creek is approximately 6.0 m AHD;

The 100 year ARI flood level upstream of the Pacific Highway crossing of the Englands Road/Marshalls Estate Tributary is approximately 5.0 m AHD.

The flood study has also provided estimated peak 100 year ARI velocities throughout the estuary. The typical peak velocities are greater than 2 m/s for much of Newports Creek downstream of the Pacific Highway crossing while at the mouth of Boambee Creek the peak velocity is between 1.6 m/s and 2 m/s. The higher velocities predicted in the Newports Creek may be influenced by the narrower cross-sectional area and smaller estuary area compared to Boambee Creek.

As explained above, it is likely that flood events are gradually getting more severe as the catchment is cleared and developed, due to the greater area of impervious surfaces.

6.4 Predicted Future Hydraulics

As identified in Section 2, the Draft Sea Level Rise Policy Statement issued by the DECCW projects sea level rise (relative to 1990 mean sea levels) of up to 40cm by 2050 and 90cm by 2100. The projected increase in sea level will raise the high and low tide levels in estuaries causing greater tidal inundation and reducing the capacity of low tides to drain low-lying areas.

In addition to this, areas subject to flooding which are influenced by tidal levels will experience greater flood levels and the flood-affected areas will expand. The changes experienced by the estuary will also result in reduced flushing of low-lying areas, creating an environment with more stagnant water.

The increased inundation levels, in isolation of any change in rainfall regime, would reduce the peak flood velocities and extend the area of influence of saline waters within the estuary.

The projected rainfall increases for the area, if they occur concurrently with the elevated sea level rise, are not expected to significantly increase the peak flow rates beyond those currently experienced for the 100 year ARI design event.


6.5 Hydraulics Summary

The hydraulic processes in the estuary are characterised by the semi-diurnal ocean tide in conjunction with hydrologic surface runoff contributed by the Boambee/Newports Creek catchment.

The tidal range in the estuary is largest at the mouth and reduces upstream to the tidal limits. The lag time between high and low tide in the estuary increases with distance upstream from the mouth.

Tidal velocities and discharges are greatest at the mouth followed by Boambee Creek and then Newports Creek.

The 100 year ARI flood level ranges from 2.6 m AHD at the railway line crossing of Boambee Creek to 6 m AHD at the Pacific Highway crossing of Newports Creek.

Entrance conditions, rainfall and development are considered to influence the hydraulics of the estuary.

Impacts of climate change are likely to increase the areas of inundation and the extent of affectation of sea waters within the estuary.


7. Water Quality

7.1 Introduction

Typically high portions of catchment nutrients from point and non-point sources are transported into deltas. In WDDs, deposition of nutrients (especially nitrogen) typically does not occur due to scouring caused by high flow events and the effects of baffling by floodplain vegetation including saltmarsh and mangrove communities (Ryan et al 2003).

A large portion of the nitrogen transported down the channel by strong river flow is exported through the mouth to the ocean. Seagrasses near the mouth and marine phytoplankton in the ocean typically assimilate the excess nutrients (Ryan et al 2003).

7.1.1 Coffs Harbour City Council

CHCC undertakes regular monitoring of 14 waterways in the local area. The purpose of this monitoring is to measure the impacts of pollution and remediation works within each catchment. From 1993 to 1998 CHCC water quality monitoring recorded faecal and total coliform levels at numerous locations within the local area. In 1999 CHCC adopted an altered water sampling program which incorporates the monitoring of pH, turbidity, Dissolved Oxygen (DO), temperature, salinity and conductivity. As part of the altered water sampling program water samples are obtained from under the footbridge across Boambee Creek in Boambee Creek Reserve on a fortnightly basis.

A summary of the data collected since 1999 at Boambee Creek is presented in Table 7-1 below. It should be noted that the data used to derive the values in Table 7-1 was not continuous and significant gaps in the data exist in some years.

The results indicate that the observed values for Faecal Coliforms and Enterococci have, on occasions, exceeded the ANZECC guideline values for recreational water quality and aesthetics.

The values obtained for salinity, temperature, DO, turbidity, pH and conductivity are consistent with the values and trends of water quality data collected by Sawtell (2002).

Across the local region, water quality monitoring indicates that in the few days after rain the water quality of the waterways in CHCC deteriorates (CHCC website). Stormwater runoff from urban and agricultural catchments contributes increased amounts of nutrients, sediment and toxicants to the waterway. Although most of these constituents are flushed from the system in the days following a rainfall event, the remaining quantities have the potential to significantly affect the short and long term water quality in the estuary.


Table 7-1 CHCC Water Quality Data for Boambee Creek, 1999 to 2008

Minimum Maximum Mean ANZECC 2000 Guidelines

Guidelines for recreational water

quality and aesthetics

Trigger Values for Slightly Disturbed

Ecosystems in South East Australia

Faecal Coliforms (colonies/ 100mL) 0 4,500 117 150^, 1000^^ -

Total Coliforms (colonies/ 100mL) 0 5,000 272 - -

Enterococci (colonies/ 100ml) 0 3,700 141 35^, 230^^ -

pH 5.9 9.46 8.3 5.0 - 9.0# 7.0 - 8.5

Conductivity (mS/cm) 4.08 55.7 45.96 - -

Turbidity (NTU) 0 70 9

Natural visual clarity should not be

reduced by more than 20%

-

DO (mg/L) 0.91 13.17 7.37 - 80-100%

Temp (°C) 15 29.8 21.9 15-35 -

Salinity (%) 0.2 40 3.5 - -

Ammonia Nitrogen * (mg/L) 0.05 0.05 0.05 - -

Nitrite Nitrogen * (mg/L) 0.05 0.05 0.05 - -

Nitrate Nitrogen * (mg/L) 0.05 0.07 0.06 - -

Total Nitrogen * (mg/L) 0.29 1.04 0.61 - 0.3

Total Phosphorus * (mg/L) 0.03 0.03 0.03 - 0.03 *Only three samples between June and August 2008 available for these parameters ^ Guidelines fro Primary Contact ^^ Guidelines for Secondary Contact # Assuming the buffering capacity of the water is low near the extremes of the pH limits

7.1.2 Manly Hydraulics Laboratory

Manly Hydraulics Laboratory (MHL) collected water quality data as part of the DECCW formerly NSW DIPNR’s Estuary Management Program. Water quality information was obtained by MHL on 4 May 2005 at thirteen sites across the Boambee/Newports Estuary, as shown in Appendix A. Water quality profiles were undertaken at high water and low water slack. The parameters that were monitored by MHL included density, temperature, salinity, DO, pH, backscatterance, chlorophyll-a and Photosynthetically Activated Radiation (PAR). The results of this monitoring and the subsequent water quality contour data from MHL are provided in Appendix A. Summaries of each of the water quality parameters are presented below.


Density

Results show the density of water is greatest at the mouth of the estuary and gradually decreases upstream during high water slack. Low water slack readings also followed this trend but showed that in deeper sections of the estuaries (stations 4 and 10) density was greater with depth. Higher density water penetrates further upstream during high water slack than during low water slack.

The density of water samples indicates the presence of ocean water. The further penetration of denser water during high water slack reflects the upstream flow of ocean water as the tide rises. Denser portions of water in the deeper sections of the estuary represents ocean water which sinks and is not actively flushed during the ebb stage of the tidal cycle.

Temperature

The variation of water temperature throughout the estuary is approximately 3.5º C. The minimum temperatures were recorded in the deeper sections of the estuary at stations 4 and 10 and warmer temperatures were observed upstream and downstream of these locations. The temperature across the estuary increases by between approximately 0.5°C and 1.5°C in the transition from high water to low water slack.

Salinity

Salinity characteristics within the estuary are similar to trends in density. High salinity is observed where high density is observed. Both parameters indicate the presence of ocean water and therefore this trend is expected.

DO

The percentage saturation of DO generally varies from close to 100% at the mouth of the estuary to less than 10% at the tidal limits. The DO levels during the high water slack were higher than samples taken during the low water slack for Boambee Creek while for Newports Creek, the reverse was observed. Insufficient data was obtained from the locations along Cordwells Creek to enable comparisons between high and low water slack.

The ANZECC DO trigger values for estuaries in slightly disturbed ecosystems in south-east Australia are 80% to 110% of saturation. DO levels inside the trigger values are not achieved at stations 5, 6, 7, 9, 12 (generally) and 13 during either high water slack or low water slack.

DO is constantly consumed in an ecosystem such as the Boambee/Newports Estuary which is inhabited by a wide range of aquatic flora and fauna. Low DO levels can be harmful to aquatic fauna and benthic communities. If these organisms cannot obtain adequate oxygen from their surrounding environment they may die off – instigating the decomposition process, which further reduces the DO levels and increases nutrients input into the aquatic environment.

Low DO levels may be an indicator of eutrophication – an environmental state where algal cells dominate the ecosystem and deplete the water of oxygen. Eutrophic environments generally generate in areas of stagnant water high in nutrients. Aesthetically, eutrophic environments are unfavourable as they are often accompanied by an unpleasant odour and increase the turbidity of water. Some algal blooms can adversely affect human health as they release dangerous toxins into the environment.


Low DO levels in the Boambee/Newports Estuary may be a result of a reduction in water disturbance and circulation.

pH

The monitoring indicates a slight decrease in pH of approximately 0.2 across the estuary from high to low water slack. Across all monitoring the pH varies between 7.1 and 8.0. The lowest pH values were observed at the upstream reaches of the estuary while the highest pH values were observed closer to the mouth of the estuary. The pH varies based on the whether there is a dominant saltwater or freshwater influence.

The pH trigger values for estuaries in slightly disturbed ecosystems in south-east Australia are less than 7 and greater than 8.5.

Backscatter

Backscatter was recorded by MHL, however, the results obtained are very site specific and be easily influenced by sediment disturbance during testing. Therefore backscatter results are not discussed in this report.

Chlorophyll-a

Chlorophyll-a concentrations are low at the mouth of the estuary and generally increase upstream. Most sites indicate an increase of chlorophyll-a concentrations during low water slack, while stations 5 and 12 show a decrease. The greatest chlorophyll-a concentrations are located at the confluence of Boambee and Cordwells Creeks. The ANZECC trigger value (4 μg/L) for estuaries in slightly disturbed ecosystems in south-east Australia is exceeded at this location. Station 7 (downstream of the tidal limit of Boambee ) and station 11 (approximately 5km upstream of the estuary mouth in Newports Creek) exceed the trigger values during low water slack.

High chlorophyll-a concentrations are an indicator of the presence of algae and nutrient concentrations in the waterway. Common nutrient sources are stormwater runoff, nutrients, sewer, sediment runoff, etc. The relatively low chlorophyll-a concentrations indicate that nutrient runoff is not a significant problem, despite the development in the catchment. However, as indicated by Ryan et al (2003), high flow events and baffling limit the deposition of nutrients in WDDs.

PAR (Photosynthetically Activated Radiation)

PAR was recorded by MHL, however, the results obtained are very site specific. Therefore PAR results are not discussed in this report.

7.1.3 Water Quality Data Collected as Part of this Study

Water quality data has also been collected by GHD to provide a recent snapshot of the conditions of the estuary. Water quality samples were obtained from the following three sites in the Boambee/Newports Estuary:

Site 1 (Boambee Creek – Railway Bridge)

Site 2 (Boambee Creek – Downstream of Confluence with Cordwells Creek)

Site 3 (Newports Creek)


The samples tested for total nitrogen, total phosphorus, total suspended solids and faecal coliforms were collected during the following two (2) sampling rounds collected on:

21 May 2009

2 June 2009

A summary of the water quality monitoring results is provided in Table 7-2.

Table 7-2 Observed Water Quality Data from this Study

Parameter Site 1 Site 2 Site 3

Mean Total Nitrogen (mg/L) 0.60 0.71 0.80

Mean Total Phosphorus (mg/L) <0.03 0.08 0.13

Mean Total Suspended Solids (mg/L) 10 25 87.5

Mean Faecal Coliforms (cfu/100mL) 290 75 120

The results indicate that the total nitrogen and phosphorus levels are similar to the results obtained by CHCC. The TSS readings for Sites 1 and 2 were relatively low while the value for Site 3 was elevated. The faecal coliform levels recorded by GHD satisfies the ANZECC guidelines for secondary contact but sometimes exceeded the levels recommended for primary contact. All of the parameters sampled on the 21 May were elevated compared to other sampling events. It is expected this is attributed to low levels of rain falling in the few days preceding the sampling and greater than 40mm falling on the sampling day.

Continuous loggers were also placed at the three locations and monitored the following parameters from 18 May 2009 through to 12 June 2009:

Water Level;

Temperature;

pH;

Dissolved Oxygen (DO); and

Electrical Conductivity (EC)

The results from the continuous loggers are presented in Figure 7-1 through to Figure 7-3 below.


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The minimum water temperatures recorded are slightly outside the values recorded by monitoring by CHCC but occur in conjunction with cooler ambient temperatures occurring in the area. Similar to the results obtained by MHL, the pH is greater towards the mouth of the estuary and varies slightly with the change in tidal level. The EC levels in the estuary differ from the results obtained by MHL in the respect that in this monitoring period the lowest EC values were obtained mid-way upstream of the estuary rather than in the upstream reaches as recorded by MHL.

Between the 21 May and 23 May the catchment received a moderate amount of rainfall. Approximately 130mm of rain fell over the 3 days and the effect of the rainfall on water quality is demonstrated by the monitoring results. Following the rainfall event, the DO in the upper reaches of the estuary increases quickly whilst temperature and EC decrease. At this site, conditions return to pre rainfall levels approximately a week after rain. The impact on the rainfall is less obvious at Site 2 which is located between the other two sites. At Site 1 the most obvious effect is the reduction of EC which takes approximately 2 weeks to return to pre-rainfall levels.

The results obtained from sampling conducted by GHD for this study are generally consistent with the values and trends of monitoring conducted by CHCC, MHL and Sawtell (2002).

7.2 Influences on Water Quality

7.2.1 Land Use

As identified in Section 3, the surrounding land use of the Boambee/Newports Estuary is highly developed. Banana plantations and grazing in the upper reaches of the catchment and industrial and residential in the lower areas of the catchment have the potential to significantly affect water


quality in the estuary. Farming typically has the effect of increasing the nutrient load in the catchment, which in turn increases the possibility of eutrophication in the receiving water body.

Compared to its natural state, urbanisation increases the likelihood of having exposed building sites, material stockpiles, unprotected road shoulders and table drains, street gutters and industrial land uses. These conditions are all well-known sources of fine sediment and collect in waterways following rainfall events. Soils in the area produce fine clay particles which give the local waterways a muddied appearance during the days after rain. The extremities of tidal influence are more likely to maintain a murky appearance for several weeks (CHCC, 2004).

7.2.2 Sewer Overflows

Sewer overflows occur in the Boambee/Newports Creek catchment as a result of storm events, equipment failure and blockages. Sewer overflows have the potential to contribute significant quantities of nutrients and bacteria to the receiving water bodies (CHCC USMP, 2000). CHCC endeavours to ensure that all sewage overflow incidents are dealt with in a swift and effective manner; however, these incidents do impact the water quality of local waterways (CHCC, 2004).

On-site-sewer management systems (OSSM) have been identified as a major source of pollution in NSW (CHCC, 2004). There were a total of 5,276 OSSM systems located in Coffs Harbour LGA in 2009 (CHCC, 2009). It is estimated that there are 657 OSSM systems located within the Boambee creek, Newports creek and Cordwells creek catchments, with 348 systems being high risk and 309 systems being low risk.

Specialist testing conducted in 2002 showed that the majority of faecal pollution in CHCC waterways was from non-human sources (CHCC, 2004).

7.2.3 MUSIC Analysis

A MUSIC analysis was performed to estimate the changing water yield, as discussed in Section 5, and pollutant loads over time for changing catchment conditions. Three MUSIC models were developed as detailed below:

Base Case: Entire catchment undeveloped – for comparative purposes;

Existing Case: Current land use properties – determined based on aerial photography; and

Fully Developed Case: Future land use properties, after completion of all allowable development – determined based on the LEP2000 without the implementation of mitigation works.

The MUSIC models predict the annual average water yield of the catchment, as well as the average annual pollutant loads of Total Suspended Solids, Phosphorus, Nitrogen and Gross Pollutants for the above three cases. The models were developed such that results could be obtained at the critical locations shown in Figure 7-4.

All models used rainfall data from 1973 to 1992 and monthly average potential evapo-transpiration data to represent the current climate at the site. Different climate data was used for the upper regions of the catchment that experience the climatic effects of the mountain range.


7.3 Predicted Future Water Quality

CHCC and DoP have identified the Boambee/Newports Creek catchment as an area to accommodate future growth in the region. Both residential and industrial land use is expected to expand in the catchment in the future, inevitably placing greater stress on water quality in the estuary. In addition to this, the RTA has announced the concept design of the Coffs Harbour bypass which consists of a four lane-duel carriageway from Englands Road to Korora Hill, in the Boambee/Newports Creek catchment. Greater development in the catchment will increase peak runoff rates upstream of detention structures, water yields and potentially pollutant loads.

The results of the MUSIC model show that after full development of the catchment total suspended solids, total phosphorus, total nitrogen and gross pollutant loads will increase. The results are shown in Table 7-3.

Projected sea level rises from climate change will influence the water quality as the effect would be an increased penetration of sea water into the estuary.

7.4 Water Quality Summary

The achievement of high quality water in the Boambee/Newports Estuary is particularly important for local community as it is used extensively for a variety of recreational activities.

Figure 7-4 and Table 7-3 show the results of the MUSIC model at several critical locations. Without the implementation of mitigation works there is predicted to be a significant increase in pollutant loadings – with the implementation of measures it would be possible to remove the effect of the increased urban development on the pollutant loads.

To mitigate the effect of sewer overflows/discharges it would be necessary to upgrade the wastewater collection and transportation system.

Figure 7-4 Water Quality Critical Locations


Table 7-3 MUSIC results at critical locations

Location Flow (GL/year)

Total Suspended Solids

(tonne/year)

Total Phosphorus (tonne/year)

Total Nitrogen (tonne/year)

Gross Pollutants (tonne/year)

Base Case

A 6.59 93.4 0.289 3.08 0

B 6.48 93.2 0.286 2.99 0

C 14.4 202 0.628 6.69 0

D 16.0 220 0.689 7.27 0

E 24.4 313 1.02 10.8 0

F 43.3 565 1.82 19.2 0

Existing Case

A 6.78 241 0.674 7.22 20.1

B 7.01 428 0.947 8.98 44.2

C 15.0 719 1.72 17.0 66.2

D 17.1 922 2.10 20.2 95.7

E 26.0 1630 3.49 31.3 153

F 46.4 2730 5.93 54.4 268

Fully Developed Case

A 6.91 297 0.754 7.71 26.5

B 7.02 434 0.955 8.97 44.7

C 16.3 1230 2.45 21.4 129

D 17.9 1250 2.60 23.4 138

E 31.7 3740 6.62 52.6 452

F 53.5 5570 10.2 83.6 665


8. Biodiversity

8.1 Introduction

Estuaries are highly dynamic and productive ecosystems, providing important environmental, commercial, recreational and biodiversity values. The valuable habitats fostered by estuaries include seagrass beds, mangrove forests, saltmarsh and freshwater wetlands, and may include a number of endangered ecological communities (EECs) listed under the Threatened Species Conservation (TSC) Act, for example Coastal Saltmarsh, Swamp Sclerophyll Forest, Swamp Oak Floodplain Forest, Bangalay Sand Forest and Freshwater Wetlands.

Estuaries provide foraging, breeding and roosting habitat for a wide range of aquatic and terrestrial fauna, as shown in Figure 8-1. Mangroves are a particularly important nursery ground for juvenile fish and also provide habitat for invertebrates, particularly crustaceans, polychaetes and molluscs (DPI, 2006). Seagrass beds are also extremely valuable habitats, providing food and shelter for many different fishes and a diverse range of crustaceans (DPI, 2005).

A variety of aquatic and terrestrial birds are also found in estuaries, including a number of threatened and migratory species.

This section of the Processes Study is aimed at determining the health and processes of the biodiversity of Boambee/Newports Estuary.


Small fish move with the tides to access mangrove areas and salt marsh for protection and food.

Mangroves provide habitat by shading water and sediment, buffering temperature and blocking UV radiation.

Some fish move upstream and downstream at different stages of their life cycles.

Mangroves are important nursery areas for some juvenile fish and crustacean larvae.

Water flow between wetland pools and estuaries allows fish to move between these habitats.

Many organisms in estuarine wetlands live in burrows or on the sediment, including worms and microbes.

Figure 8-1 Physical Habitat Values (OzCoasts, 2009)

8.2 Biodiversity Study Methodology

Prior to undertaking field surveys, information pertaining to previous investigations of Boambee/ Newports Estuary, studies of similar estuaries and other relevant background information were gathered and reviewed. Additionally, database searches were conducted to identify any threatened species and EEC that may inhabit or utilise the study area. The desktop assessment component of the biodiversity study provided background information to enable a greater understanding of the study area’s ecological values.

The desktop assessments were followed by fieldwork to groundtruth the information from the desktop investigations and provide overall health and condition values for the riparian and estuarine vegetation communities/ habitats. The Rapid Appraisal of Riparian Condition (RARC) methodology was used for riparian vegetation whilst the Wetland Assessment Technique was used for estuarine vegetation (mangroves, saltmarshes and seagrass beds). The health and condition values provided a basis for determining the habitat values of the surveyed vegetation communities and hence the Estuary’s biodiversity.


8.2.1 Database Searches and Literature Review

The study area has been the subject of a number of investigations. A review of available literature, aerial photographs, maps, relevant flora and fauna studies and database records pertaining to the ecology and environmental features of the study area and locality was undertaken to provide background information prior to undertaking the field surveys. A full reference list of the database searches and literature reviews are provided in Appendix B.

8.2.2 Riparian Vegetation Assessment Methodology

The survey methodology that was used to evaluate the health and condition of the terrestrial/ riparian vegetation communities of the study area is the RARC.

RARC surveys were undertaken on the 9th, 10th and 13th of June 2009 and involved the surveying of 24 targeted sites throughout the Estuary from the entrance to the upper tidal limits of Boambee, Cordwells and Newports Creeks. The sites were selected to ensure each vegetation community type was assessed and there was an even distribution of sites along the Estuary. The location of the sites is shown in Figure 8-2.

The RARC methodology is used to assess and monitor the riverbank condition of rivers, streams and estuaries. This methodology was developed by the Commonwealth Department of Land and Water Australia and is compatible with AUSRIVAS methodologies. The method is used to score a number of vegetation attributes in the riparian zone, including:

Habitat continuity and extent (HABITAT);

Vegetation cover and structural complexity (COVER);

Dominance of natives versus exotics (NATIVES);

Standing dead trees, fallen logs and leaf litter (DEBRIS); and

Indicative features of a diverse intact riparian (FEATURES).

8.2.3 Estuarine Vegetation Assessment Methodology

The Wetland Assessment methodology was derived from the Wetland Assessment Techniques Manual for Australian Wetlands (Price et.al., 2008). This methodology evaluates the overall health and condition of wetland vegetation communities that occur in all wetland types (saline or freshwater).

On the 9th, 10th and 13th of June 2009, 5 saltmarsh, 10 mangrove and 8 seagrass sites were assessed along the Estuary. The sites were selected to ensure each vegetation community type was assessed and there was an even distribution of sites along the Estuary. The location of the sites is shown in Figure 8-2.

This methodology involved recording a score for a number of attributes of each community type. The total score is compared to an established ranking system that indicates the ecological health of the site/community.

The limitations of both survey methodologies included:

The surveys were undertaken within 3 months of a major flood event by which some of the debris, leaf litter etc. may have been removed by floodwaters; and


Not all communities were surveyed.

Further detail of the survey methodologies used in this study are provided in Appendix B.

8.3 Description of Flora Biodiversity

The existing biodiversity has been assessed in regards to the condition and health of riparian vegetation and estuarine vegetation communities located throughout the Estuary. By knowing the health and condition of vegetation communities it is possible to determine the habitat values of the vegetation communities and hence the level of biodiversity that the Estuary may be able to support. The level of biodiversity relates to the effectiveness of the ecological processes of the Estuary and its long-term sustainability, ecosystem resilience and ecological function.

8.3.1 DECCW Database Search Results

A five kilometre search of the NSW DECCW, Bionet and EPBC database revealed that approximately 825 flora species have been previously recorded in the Boambee/Newports Creek Estuary’s estuarine and terrestrial habitats. Of the 825 flora species 33 are listed as threatened and 132 as exotic. This indicates a high level of biodiversity within the terrestrial and estuarine habitats of the Estuary. It also implies that the vegetation communities are in relatively good health and condition and capable of supporting a diverse range of fauna.

8.3.2 Terrestrial Flora Biodiversity

In the 1940’s, the catchment was well vegetated with the majority of land clearing having occurred on the lower slopes for agricultural development. This resulted in the removal of a large proportion of riparian vegetation in the mid to upper sections of the catchment. Over the following 20-30 years land clearing occurred on the steeper upper slopes of the catchment for banana plantations.

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LEGEND

© 2010. While GHD has taken care to ensure the accuracy of this product, GHD and COFFS HARBOUR CITY COUNCIL make no representations or warranties about its accuracy, completeness or suitability for any particularpurpose. GHD and COFFS HARBOUR CITY COUNCIL cannot accept liabil ity of any k ind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or maybe incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.


22-14220

Date 06 MAY 2010oCoffs Harbour City CouncilBoambee / Newports Estuary

Biodiversity Survey Locations &Riparian Vegetation Communities

Data Source: Coffs Harbour City Council: Cadastre, Aerial & Riparian Vegetation - 2008. Created by: fmackay, tmorton




1:25,000 (at A4)

CatchmentsCadastre

Riparian Transects

Riparian VegetationForedune Complex

Headland heath and grassland

Heathland/ Shrubland Vegetation

Littoral RainforestMangrove/Saltmarsh Complex

Open Forest

Riparian Vegetation

Sedgeland/ Rushland ComplexSub-Tropical Rainforest

Swamp Forest

Swamp forest

Tall Open ForestWet Heath


It is also apparent from historical aerial imagery of the catchment that the general distribution of subtropical rainforest and wet sclerophyll forest vegetation communities in the uppermost slopes, as well as the coastal floodplain forest and wet sclerophyll forest of the lower catchments floodplain are similar to the present day. It is the mid to upper slopes of the catchment where the vegetation communities have been modified for agricultural purposes.

DoP (2007) reported that 70 % of the entire catchment has been cleared of vegetation. As shown in Figure 1-1, the most significant clearing is in the mid to lower catchment with the upper catchment remaining reasonably well vegetated. However, the riparian vegetation in the mid to lower catchment appears to be revegetating as agricultural activity ceases or is being replaced with rural residential development. The vegetation of the uppermost parts of the catchment is reserved as Boambee State Forest.

The terrestrial vegetation communities of the broader catchment are subtropical rainforest, swamp forest, tall open forest and open forest (Fisher, et al, 1996). Most of the tall open forest and open forest is managed by Forests NSW and is managed as harvestable plantations. No detailed assessment of these vegetation communities where undertaken, however they are assumed to be in reasonable condition.

In summary, the terrestrial biodiversity of the catchment is considered higher in the lower and uppermost catchment than that of the mid to upper catchment where anthropogenic disturbances have been greatest. The presence of wildlife corridor linkages in the riparian and adjoining terrestrial vegetation communities are not ideal due to their reduced width, however they do provide continuous linkages throughout the catchment from the estuary to the escarpment and are best in the lower and uppermost parts of the catchment.

The health of the vegetation communities of the entire catchment is vital to the health and long-term sustainability of the Estuary processes because they:

Stabilise the topsoil;

Reduce sedimentation of the Estuary and freshwater creeks;

Provide habitat corridor linkages;

Regulate surface water runoff;

Reduce creek bank erosion;

Support a variety of fauna and flora species; and

Provide groundwater recharge in the uppermost catchment.

The current threats to the long-term sustainability of the terrestrial biodiversity of the broader catchment and its flora species include:

Habitat destruction through land clearing; and

Weed infestation.

8.3.3 Riparian Vegetation Biodiversity

The review of vegetation mapping concluded that the study area contains 10 riparian vegetation communities that are floristically different from one another. The riparian vegetation communities and survey locations are depicted in Figure 8-2. CHCC’s vegetation mapping has each vegetation community


of the LGA classified according to Fisher et al (1996) and the Regional Vegetation Communities (RVC) of the Northern Rivers Catchment Management Authority (NRCMA) region.

At least one of each riparian vegetation community was surveyed using the RARC methodology. The outcomes of the RARC surveys are summarised in Table 8-1.

Table 8-1 Summary of RARC Survey Results

RARC Condition Scoring (score out of)

Habitat Cover Natives Debris Features Totals Site ID Stream Name Regional Vegetation Community (RVC)

11 12 9 10 8 50

R1 Boambee Ck RVC 9 11 9.25 9 6 6.75 42

R2 Boambee Ck RVC 33 11 11.25 9 8.5 4 43.75

R3 Boambee Ck RVC 9 11 9.5 9 6.5 5.75 41.75

R4 Boambee Ck RVC 3 11 9.75 7 7 2 36.75

R5 Boambee Ck RVC 11 modified 3.5 7.5 7 3.5 1.25 22.75

R6 Boambee Ck RVC 9 modified 3 8.5 5.75 3 2.25 22.5

R7 Boambee Ck RVC 9 8.75 9.25 4.5 4.5 2.75 29.75

R8 Boambee Ck RVC 10 8.25 9.75 8.75 3.75 5.5 36

R9 Boambee Ck RVC 33, RVC 9 11 11.5 9 8.25 4.25 44

R10 Boambee Ck RVC 9 11 9.75 9 7.75 1.75 39.25

R11 Boambee Ck RVC 9 11 8 5.75 4.5 1.75 31

R12 Newports Ck RVC 29 10.25 11.25 6.75 7.25 4.5 40

R13 Newports Ck RVC 33 11 11 8.5 7.75 4.75 43

R14 Newports Ck RVC 9 11 10.5 8.25 6.75 4 40.5

R15 Newports Ck RVC 9 10.5 9.75 9 5.25 5.25 39.75

R16 Newports Ck RVC 39 11 10 9 6 5.5 41.5

R17 Newports Ck RVC 9 10 11 9 6.5 5 41.5

R18 Newports Ck RVC 39 8.75 8.75 8.25 4.75 5 35.5

R19 Newports Ck RVC 9 10.75 9.5 9 7.5 3.25 40

R20 Boambee Ck RVC 9 11 11.25 8.25 5.5 3 39

R21 Boambee Ck RVC24 11 11 9 8 2.25 41.25

R22 Boambee Ck RVC9 8.5 7.75 6 5 2 29.25

R23 Boambee Ck RVC9 11 10.75 8.5 7.25 3 40.5

R24 Boambee Ck RVC9 11 10.75 9 7.75 2.5 41

Average Scores 9.84 9.89 8.01 6.19 3.67 37.59


The following provides descriptions of the Fisher, et al (1996) and RVCs that were surveyed using the RARC methodology.

Foredune Complex (Fisher) - RVC 3 Coast Banksia low open forest on coastal dunes, North Coast Bioregion

This vegetation community extends northwards along the dunes associated with Boambee Beach with only a small portion located in the riparian zone of the Estuary, as shown in Figure 8-2. RARC 4 assessed this community’s condition. The dominant plant species included Coast Banksia (Banksia integrifolia), Black She-oak (Allocasuarina littoralis) and Coastal Wattle (Acacia sophorae). Bitou Bush (Crhysanthemoides monilifera) was scattered through the understorey.

Headland Heath and Grassland (Fisher) - RVC 7 Coastal headland heaths, Coastal NSW

This vegetation community is located on the headland south of the Estuary entrance and was not surveyed because of its elevation above the Estuary and the steep rocky terrain of this riparian zone, as shown in Figure 8-2. The dominant plant species include Black She-oak, Swamp She-oak (Casuarina glauca), Coast Banksia and Dogwood (Jacksonia scoparia).

Swamp Forest (Fisher) - RVC 9 Paperbark swamp forest of the coastal lowlands, Coastal NSW

This vegetation community is the most dominant riparian vegetation community of the Estuary and is found throughout the Estuary, as shown in Figure 8-2. RARC 1, 3, 6, 7, 10, 11, 14, 15, 17, 19, 20, 22, 23 and 24 assessed this community’s condition. The dominant species include Broad-leaved Paperbark (Melaleuca quinquenervia) and Swamp Turpentine (Lophostemon suaveolens). Tallowwood, Swamp She-oak, Pink Bloodwood and Blackbutt where also present in this community. The noxious weeds Bitou Bush, Lantana and Giant Parramatta Grass (Sporobolus fertilis) where found in low numbers at some of these RARC locations.

Swamp Forest (Fisher) - RVC 10 Swamp Mahogany – Swamp Box swamp forests of coastal lowlands, NSW North Coast

This vegetation community is found just below the confluence of Newports and Boambee Creeks, as shown in Figure 8-2. RARC 8 assessed this community’s condition. The dominant species included Swamp Mahogany, Broad-leaved Paperbark and Black She-oak.

Open Forest (Fisher) - RVC 11 Grey Box – Forest Red Gum – Grey Ironbark open forest of the hinterland ranges, NSW North Coast

This RVC best fits this vegetation community and RARC 5 assessed its condition. It is located at Boambee Creek Reserve near the entrance of the Estuary, as shown in Figure 8-2, and its modified state may be the reason why it does not specifically fit this RVC. The dominant species included Forest Red Gum (Eucalyptus tereticornis), Black She-oak and may typically contain Pink Bloodwood (Corymbia

intermedia).

Tall Open Forest (Fisher) - RVC 24 Blackbutt - Tallowwood tall moist shrubby forests, NSW North Coast

This vegetation community is found in the upper reaches of the Estuary associated with Boambee and Cordwells creeks, as shown in Figure 8-2. RARC 21 assessed this community’s condition. The dominant species included Blackbutt and Tallowwood. Lantana was sparsely scattered through the understorey.


Tall Open Forest (Fisher) - RVC 29 Tallowwood tall moist shrubby forests, NSW North Coast

This vegetation community is found in the upper tidal limit of Newports Creek east of the Pacific Highway, as shown in Figure 8-2. RARC 12 assessed this community’s condition. The dominant species included Tallowwood, Blackbutt and Brush Box. Flooded Gum (Eucalyptus grandis), Pink Bloodwood, Turpentine and Swamp Mahogany (E. robusta) where also present in this community. Camphor Laurel (Cinnamomum camphora) and Lantana was scattered throughout this community.

Open Forest (Fisher) - RVC 33 Red Mahogany open forest of the coastal lowlands, NSW North Coast

This vegetation community is found at different locations throughout the riparian zone of the Estuary from behind the dunes close to the Estuary entrance upstream to where the highway crosses, as shown in Figure 8-2. RARC 2, 9 and 13 assessed this community’s condition. The dominant plant species varied slightly from site to site and included Blackbutt (Eucalyptus pilularis), Red Mahogany (E. resinifera), Pink Bloodwood (Corymbia intermedia), and Tallowwood (E. microcorys). Broad-leaved Paperbark (Melaleuca quinquenervia), Coast Banksia, Black She-oak, Turpentine (Syncarpia glomulifera) and Brush Box (Lophostemon confertus) where also present in these communities.

Sedgeland/ Rushland Complex (Fisher) - RVC 39 Wet heaths and sedgelands, coastal NSW

This vegetation community is found in the lower and mid reaches of Newports Creek, as shown in Figure 8-2. RARC 16 and 18 assessed this community’s condition. The dominant species included Sea Rush (Juncus kraussii) with Black She-oak along the riparian edge.

8.3.4 Summary of Riparian Vegetation Condition

In general, the riparian vegetation communities surveyed were in very good condition with an average score of 37.59 out of 50, inferring good habitat values and ecological function. This was indicated by an excellent average habitat score of 9.84 out of 11, as a result of effective connectivity and/or proximity to other vegetation communities within the study area, thus providing linkages between important wildlife corridors. This was further indicated by an average natives score of 8.01 out of 9 as determined by the high presence of native flora throughout the stratum layers.

The average cover score was 9.89 out of 12 as determined by the existing coverage of the canopy, understorey and groundcover. This is an indicator of good biodiversity, because many terrestrial species such as small birds prefer to have breeding and foraging habitat that is multi-layered. The average debris score was 6.19 out of 10 and reduces the overall biodiversity slightly, as it is based on potential fauna habitat in the form of hollow bearing trees, standing dead trees and fallen logs. The lack of these attributes indicates that the riparian vegetation may be regrowth and not old growth.

The results indicated that the riparian vegetation communities provide for a high level of biodiversity, as is apparent with the number of flora and fauna species recorded in the study area, and as such, ecological processes are optimised. The edge effects between terrestrial and estuarine ecosystems are continuous throughout most of the Estuary enabling effective energy and nutrient movements between the two ecosystems and throughout the food chain.

The hydrodynamic processes of the Estuary are benefited by the condition of the riparian vegetation because the vegetation would be assisting in regulating the volume of runoff from the catchment via transpiration. Riparian vegetation would also be assisting in decreasing the volume of sediment entering


the system by actively capturing some of the ground surface sediments associated with surface runoff and by stabilising the banks of the Estuary.

The lowest scores were associated with areas modified for human use, such as RARC 5 (22.75) and RARC 6 (22.5) associated with Boambee Creek Reserve. RARC 7 (29.75) located just upstream from the Boambee Creek Reserve and RARC 11 (31) upstream from the confluence of Boambee Creek and Newports Creek are also modified through past or present human activities. In many places, disturbances were the result of vehicular access in the form of four-wheel drives, car and motorbike tracks. Footpaths regularly used by humans were also evident in most of the sites surveyed. It is along these tracks and footpaths that weed species were observed, especially Giant Parramatta Grass, Lantana, Bitou Bush and Camphor Laurel. Lantana and Bitou Bush are listed as weeds of National Environmental Significance (NES). Noxious weeds are very invasive and are capable of reducing the habitat values of vegetation communities. At present, the distribution of noxious weeds is limited in the riparian vegetation of the Estuary but to maintain the ecological integrity of these communities, these species will need to be controlled.

8.3.5 Estuarine Vegetation

As explained earlier, estuarine wetlands are vital to the health of an estuary. The DECCW formerly Department of Natural Resources (DNR) has produced a Map of Estuarine Vegetation and Habitats for the Boambee/Newports Estuary (Figure 8-3) that was developed by a combination of Estuarine Vegetation Mapping undertaken by NSW Fisheries and the Department of Planning's NSW Comprehensive Coastal Assessment Project (DoP, 2007).

The Boambee/Newports Estuary would typically have low sediment trapping efficiency; naturally low turbidity and a low risk of habitat loss due to sedimentation (GA, 2009). However, due to human settlement, sedimentation has increased, turbidity has increased and habitats have changed as is depicted in Figure 8-4 below.

0

10

20

30

40

50

60

70

1954 1964 1974 1984 1994Years

Ch

ang

e (h

a)

MangroveSaltmarshSeagrass Beds

Figure 8-3 Changes in the Distribution of Estuarine Vegetation in Hectares 1954 – 1994 (Sawtell,

2002)

Figure 8.4G:\22\14223\GIS\Maps\Estuary Management Plan\2214223_EMP_FIG8-3_Vegetation_20090819_A.mxd

0 170 340 510 68085

Metres

LEGEND

© 2009. While GHD has taken care to ensure the accuracy of this product, GHD and DEPARTMENT OF NATURAL RESOURCES make no representations or warranties about its accuracy, completeness or suitability for anyparticular purpose. GHD and DEPARTMENT OF NATURAL RESOURCES cannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage)which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.


22-14220

Date 19 AUG 2009oCoffs Harbour City CouncilBoambee / Newports Estuary

DNR Map of EstuarineVegetation and Habitats 2007

Data Source: Department of Natural Resources: Vegetation Image - 2008. Created by: fmackay




Saltmarsh

Seagrass

Mangrove

Mangrove Limits

Estuary


The section below discusses the distribution and health of each estuarine wetland community and the associated processes.

Coastal Saltmarsh (Endangered Ecological Community)

Figure 8-3 indicates that saltmarsh is limited in extent but is distributed throughout the Estuary. The saltmarsh communities in the Estuary are dominated by Sand Couch (Sporobolus virginicus) in association with Sarcocornia quinqueflora supsp. quinqueflora at most survey locations. Sea Rush (Juncus kraussii) was found around the margins of most of the saltmarshes surveyed where the freshwater runoff had a greater influence. The greater freshwater influence also contributed to the saltmarsh located at the tidal limit of Cordwells Creek being dominated by Common Reed (Phragmites australis).

The reason saltmarsh is more abundant in the lower and mid sections of the Estuary is likely to be because saltmarsh species are adapted to saline and hyper saline conditions and this is often their advantage over more terrestrial species. As the saline influence decreases and freshwater influence increases along the Estuary, the more competitive terrestrial species become. Terrestrial species have the added advantage of generally being larger species that, once established, can overshadow the saltmarsh species.

Sawtell (2002) assessed the changes in saltmarsh extent in the Boambee/Newports catchment between 1954 and 1994. As Figure 8-4 indicates, there has been a steady decline of 37% in saltmarsh extent over this period. A number of factors may have contributed to this decline but it is considered that development is the most significant. Saltmarsh is particularly vulnerable to development because it is on the landward side of the Estuary. Sawtell (2002) found that a significant relationship exists between the increase in development and decrease in saltmarsh extent.

The decline in saltmarsh extent may also be attributed to natural fluctuations in its response to changes in hydrodynamic, sediment and nitrogen processes. Climate change and rising sea levels may see coastal saltmarshes vanish, as such, a dramatic change may be imperative to the persistence of this vegetation community.

The results of the Wetland Assessment of Saltmarsh Condition indicated that the average condition index of the coastal saltmarsh surveyed was 63.33 % ranging between 50 % – 83.33 %. The condition index and health rating for each saltmarsh surveyed is depicted in Table 8-2. SM2 and SM3 are in poor

to average health and therefore support a low level of biodiversity, whilst SM4 was found to be in very good health and may support a high level of biodiversity followed closely by SM1 and SM4 that are in good health and may support a moderate level of biodiversity.

The overall average health rating for the coastal saltmarsh ecosystems of the Estuary is medium inferring that this component of the estuarine wetland is able to support a moderate level of biodiversity based upon its current health rating. It also infers that the ecological processes of this component are currently moderate and somewhat inefficient. This would need to improve to ensure that the coastal saltmarshes of the Estuary are able to continue supporting the current level of biodiversity or greater, as well as ensuring that ecological processes are maintained at the current levels or improved.


Table 8-2 Coastal Saltmarsh Condition Index and Health Rating

Saltmarsh ID Saltmarsh Condition Index Health Rating

SM1 66.67 Good

SM2 50 Poor to Average

SM3 50 Poor to Average

SM4 83.33 Very Good

SM5 66.67 Good

Estuary Average 63.33 Medium

The medium health rating of the coastal saltmarsh is indicative of past disturbances and the ever increasing encroachment of mangroves and development. The sediment and nitrogen processes that support the saltmarsh appear to be operating effectively as was indicated by the health of the vegetation surveyed and the lack of necrosis.

8.3.6 Mangrove Forests

Mangroves exist throughout the Estuary with some significant and well-established communities, especially in Boambee Estuary. The Grey Mangrove (Avicennia marina) was the dominant mangrove species recorded throughout the Estuary and at some locations it was associated with the River Mangrove (Aegiceras corniculatum). Milky Mangrove (Excoecaria agallocha) was recorded at one location. The prevalence and distribution of River Mangrove increased towards the upper tidal limits of the Estuary.

An analysis of mangrove extent, in the Boambee/Newports Estuary, between 1954 and 1994, indicates that mangroves have experienced a 20.3% increase (Sawtell, 2002), as shown in Figure 8-3. A significant relationship was established between the increase in mangrove extent and development (Sawtell, 2002). The processes controlling this increase are most likely to be increased sedimentation and possibly sea level rise.

The greatest increase in mangrove extent was between 1964 and 1974 which coincides with the greatest increase in development and banana plantations (Sawtell, 2002). It is possible that increased sedimentation during this period established suitable habitat for mangrove colonisation. The mangroves themselves may have contributed to the sedimentation process by trapping sediments in their pneumatophore root system.

Sea level may have provided suitable conditions for the landward expansion of mangroves. The observed encroachment of mangroves on areas of saltmarsh suggest this may be occurring in some locations but it is not considered to be significant at this stage.

The results of the Wetland Assessment of Mangrove Condition indicated that the average condition index of the mangrove forests surveyed was 70 % ranging between 50 % – 100 %, as shown in Table 8-3. M2 was in poor to average health and therefore may support a low level of biodiversity, whilst M5 and M6 were found to be in excellent health and may support a high level of biodiversity. The overall average health rating for the mangrove communities in the Estuary was good.


The overall average health rating for the mangrove forest ecosystems of the Estuary is good inferring that this component of the estuarine wetland is able to support a moderate to high level of biodiversity based upon its current health rating. It also infers that the ecological processes of this component are currently moderate to high. This needs to be maintained or improved to ensure that the mangrove forests of the Estuary are able to continue supporting the current level of biodiversity, as well as ensuring that ecological processes are maintained at the current levels.

Table 8-3 Mangrove Condition Index and Health Rating

Mangrove ID Mangrove Condition Index Health Rating

M1 60 Medium

M2 50 Poor to Average

M3 60 Medium

M4 70 Good

M5 100 Excellent

M6 100 Excellent

M7 70 Good

M8 60 Medium

M9 60 Medium

M10 70 Good

Estuary Average 70 Good

The distribution and good condition rating of the mangrove forests is indicative of effective nitrogen, hydrodynamic and sediment processes taking place within the Estuary as these processes are fundamental to the health and condition of mangrove forests.

8.3.7 Seagrass Beds

Seagrass communities are well established in the lower to mid estuary, with Zostera capricorni being the sole seagrass species found in the Estuary. One of the largest seagrass communities is located in the upper mid section of Boambee Estuary. It is likely that Boambee Estuary is more suitable to seagrass due to its lower turbidity and sedimentation processes. The restricted distribution of seagrass to the mid to lower and shallower sections of the Estuary may be the result of increased sediment loads of the upper Estuary restricting sunlight penetration for seagrass photosynthesis, as well as the creeks becoming narrower with greater mangrove and or riparian vegetation overhang also restricting light penetration.

Sediment stability is another factor influencing seagrass distribution. Seagrasses occur in low energy environments with limited water and sediment movement. They are adapted to periodic disturbances from floods but sustained sediment movement is likely to create unfavourable conditions for seagrass (WBM, 2005). This may explain why there is limited seagrass in the lower Estuary. The strong tidal


currents and wave action in this section of the Estuary are likely to be less favourable to seagrass than the more stable, lower energy mid section.

Seagrass extent has fluctuated between 1954 and 1994 (Sawtell, 2002). As shown in Figure 8-4, the area of seagrass beds increased to 1973 and has since been steadily decreasing, although there has been an overall increase of 57% increase in seagrass in the Estuary over this time period. The peak in seagrass extent correlates with the peak in banana growing activities in the upper catchment. Since this time, banana plantations have declined along with a slow decline in seagrass beds. This suggests there is a positive link between seagrass extent and banana plantations, however Sawtell (2002) indicates that there is a relationship between increased development and a decrease in seagrass extent. Most studies have indicated that increased sedimentation from development negatively impacts on seagrass by reducing light penetration, smothering and increasing nutrients which increases epiphytic algal growth.

The results of the Wetland Assessment of Saltmarsh Condition indicated that the average condition index of the seagrass beds surveyed was 73.21 % ranging between 64.29 % – 78.57 %. The condition index and health rating for each seagrass bed surveyed is depicted in Table 8-4. SG3, SG6 and SG7 have a medium health rating and therefore support a moderate level of biodiversity, whilst SG1, SG2, SG4, SG5 and SG8 have a very good health rating and may support a moderate to high level of biodiversity.

The overall average health rating for the seagrass bed ecosystems of the Estuary is good inferring that this component of the estuarine wetland is able to support a moderate to high level of biodiversity based upon its current health rating. It also infers that the ecological processes of this component are moderate to high and efficient. This needs to be maintained to ensure that the seagrass beds of the Estuary are able to continue supporting the current level of biodiversity, as well as ensuring that ecological processes are maintained at the current levels.

Table 8-4 Seagrass Bed Condition Index and Health Rating

Seagrass ID Seagrass Bed Condition Index Health Rating

SG1 78.57 Very Good

SG2 78.57 Very Good

SG3 64.29 Medium

SG4 78.57 Very Good

SG5 78.57 Very Good

SG6 64.29 Medium

SG7 64.29 Medium

SG8 78.57 Very Good

Estuary Average 73.21 Good

The good health rating is indicative of effective hydrodynamic, nitrogen and sediment processes that provide the seagrass beds with nutrients, organic matter and good light penetration. However, if sediment loads were reduced, the seagrass beds may potentially occur further up the Estuary and at


greater depths than where they currently exist. In turn this would provide a greater abundance of habitat (nursery grounds) for juvenile, fish prawns and shellfish.

8.4 Terrestrial and Marine Fauna Biodiversity

The vegetation communities of the Boambee/Newports Estuary provide habitat for essential terrestrial and aquatic species. A five kilometre search of the NSW DECCW, Bionet and EPBC database revealed that approximately 355 terrestrial and marine fauna species have been previously recorded in the Boambee/Newports Creek estuarine and terrestrial habitats. Of the 355 fauna species 41 are listed as threatened and 18 are exotic. This indicates a high level of biodiversity within the Estuary.

8.4.1 Aquatic Invertebrates

Invertebrates play an important role in maintaining estuarine ecosystems by cycling nutrients, turning over sediments, providing food for many fish and waders and forming a key link in estuarine foodwebs (WBM, 2005).

An investigation into the benthic organisms of four sites within the Boambee/Newports Estuary was undertaken by Sawtell (2002) in 1997 and 1999. A range of bivalve, amphipod, gastropod and polychaete species was recorded. The dominant species varied between sites and years. The dominant species in the lower Estuary (Site 1) in 1997 was the bivalve Tellina deltoidalis and in 1999 it was the gastropod Potamididae family. In the mid Estuary, Site 2 was dominated by amphipod species Urohaustorid while Site 3 was dominated by the bivalve Tellina deltoidalis. Site 4, located in the upper Estuary, was dominated by polychaetes Capitella capitata and Notomastus estuaries.

In general, Sites 3 and 4, in the mid section of the Estuary, indicated the greatest abundance and diversity of benthic species.

Factors influencing the benthic species diversity, distribution and abundance were only briefly explored with no definitive relationship established. The factors considered by Sawtell (2002) and WBM (2005) included:

Sampling Period: Sampling was undertaken in different seasons.

Sediment Type: Sediments in the upper and mid Estuary typically have higher organic matter content which provides a valuable food source for benthic organisms.

Sediment Stability: Benthic species have varying tolerances to wave/current disturbance. Areas exposed to high wave and current action typically have less species than more stable areas.

Water Quality: Benthic species have varying tolerances to water quality conditions. Some species can tolerate poor water quality while others require stable healthy conditions.

Biological interactions: This includes factors such as competition, predation and recruitment.

The Estuary is also known to support other important invertebrates, including prawns, mud crabs and blue swimmer crabs. Nippers (Trypaea australiensis) are also prevalent in the sand and mud bars throughout the lower to mid Estuary. Nippers are an important food source for estuarine fauna and a favourite bait for local fishermen.


8.4.2 Aquatic Fauna

Thirty six aquatic fauna species have been recorded in the Boambee/Newports Estuary area. This includes one threatened species. This high level of biodiversity can be attributed to the health and condition of the estuarine vegetation communities in particular the mangrove forests and seagrass beds that provide excellent habitat (nursery grounds) for juvenile, fish prawns and shellfish.

The threatened species considered likely to use the Estuary is Black Cod (Epinephelus daemenelii). Black Cod has been recorded from southern Queensland to Kangaroo Island in South Australia. In Australia it is found on coastal and offshore reefs and islands and is an aggressive territorial species that may occupy a particular cave for life. The rocky southern bank of the entrance of the Estuary may provide suitable habitat for the Black Cod.

The Estuary also supports numerous commercial and/or recreational fish species. The most common commercial and recreational fish species include Australian Bass, Bream, Flathead, Garfish, Leatherjacket, Ludrick, Mangrove Jack, Mullet, Mulloway, Octopus, Tailor, Trevally and Whiting.

The estuarine species are important to the processes of the Estuary but are susceptible to changes in estuarine conditions. Changes that can impact on the distribution, diversity and abundance of estuarine species include:

Eutrophication – This can occur when there is an increase in nutrients in the estuary. This stimulates phytoplankton and macroalgae growth. When the organic matter is degrading it reduces the oxygen in the water leading to anoxic conditions. Some phytoplankton and macroalgae are toxic.

Hydrological Stress - Changes in the hydrology of an estuary can influence the life-cycle of aquatic organisms. It may also influence the distribution of some species.

Overfishing – Boambee/Newports Estuary is open to both recreational and commercial fishing. If not controlled, this could place significant pressure on the target species.

Acid Runoff – Acidic runoff from areas of acid sulfate soils has the potential to significantly lower the pH of the water and release toxic chemicals into the water. These conditions can severely affect aquatic organisms and has been attributed to fish kills in a number of NSW estuaries.

Water Deoxygenation – When a large volume of deoxygenated water or organic matter enters an estuary, anoxic conditions can result. This can lead to extensive fish kills as observed in the Richmond River.

Habitat Destruction – Suitable habitat is essential to ensure healthy aquatic species. When aquatic habitat is destroyed or negatively impacted, this affects the aquatic species that rely on this habitat.

Pollution – When chemicals, sediment and/or gross pollutants enter the water they can have a significant effect on aquatic species.

Exotic Species – Exotic species can compete and predate on native species which leads to a reduction in their health and abundance.

The above impacts can have chronic or acute impacts on an ecosystem, as observed in the Boambee/Newports Estuary on the 17th August, 1998, when a large fish kill occurred (Sawtell, 2002). For a number of kilometres along either side of the confluence of Boambee and Newports Creeks, dead and dying fish were evident on the bank and in the water. The kill also included fish eating birds, such as a number of Pelicans (Sawtell, 2002). The cause of the fish kill was not identified.


8.4.3 Terrestrial Fauna Biodiversity

The vegetation communities provide habitat for a diverse range of species as indicated by the database search results. The DECCW database search revealed 319 species including 18 amphibians, 216 birds, 57 mammals and 29 reptiles, of which 40 species are listed under the NSW Threatened Species Conservation Act (TSC Act). The listed threatened species included:

One Amphibian

Wallum Froglet (Crinia tinnula).

Twenty-Four Birds

Flesh-footed Shearwater (Puffinus carneipes);

Wompoo Fruit-dove (Ptilinopus magnificus);

Masked Booby (Sula dactylatra); Rose-crowned Fruit-dove (Ptilinopus

regina);

Black Bittern (Ixobrychus flavicollis); Glossy Black Cockatoo (Calyptorhynchus

lathami);

Black-necked Stork (Ephippiorhynchus asiaticus);

Double-eyed Fig-parrot (Cyclopsitta diophthalma coxeni);

Square-tailed Kite (Lophoictinia isura); Swift Parrot (Lathamus discolor);

Osprey (Pandion haliaetus); Barking Owl (Ninox connivens);

Comb-crested Jacana (Irediparra gallinacea);

Powerful Owl (Ninox strenua);

Beach Stone-curlew (Esacus neglectus); Grass Owl (Tyto capensis);

Sooty Oystercatcher (Haematopus fuliginosus);

Masked Owl (Tyto novaehollandiae);

Pied Oystercatcher (Haematopus longirostris);

Collared Kingfisher (Todiramphus chloris);

Little Tern (Sterna albifrons); Regent Honeyeater (Xanthomyza phrygia);

and

Sooty Tern (Sterna fuscata); Barred Cuckoo-shrike (Coracina lineata).

Fifteen Mammals

Spotted-tailed Quoll (Dasyurus maculatus); Eastern Freetail-bat (Mormopterus

norfolkensis);

Brush-tailed Phascogale (Phascogale

tapoatafa); Little Bentwing-bat (Miniopterus australis);

Australian Fur-seal (Arctocephalus pusillus

doriferus); Eastern Bentwing-bat (Miniopterus

schreibersii oceanensis);

Grey-headed Flying-fox (Pteropus

poliocephalus); Large-footed Myotis (Myotis adversus);


Yellow-bellied Glider (Petaurus australis); Greater Broad-nosed Bat (Scoteanax

rueppellii);

Squirrel Glider (Petaurus norfolcensis); Common Planigale (Planigale maculata);

and

Koala (Phascolarctos cinereus); Dugong (Dugong dugon).

Common Blossom-bat (Syconycteris

australis);

Not all of the threatened species listed are likely to occur in the Estuary permanently, as some of them are transient species that may only visit the Estuary on a temporary basis.

The Commonwealth EPBC Act Protected Matters search revealed 2 amphibians, 4 mammals and 14 birds. Of the listed bird species 3 are sedentary, 7 are terrestrial migratory and 4 are migratory wetland species.

The catchment contains a high proportion of high value Koala habitat. This is evident in a high presence of Koala feed trees such as Tallowwood, Forest Red Gum and Swamp Mahogany. The presence of hollow bearing and standing dead trees in some of the less disturbed areas of the catchment may provide suitable roosting habitat for endangered bat species and forest owls.

8.5 Predicted Future Biodiversity

The protection of existing biodiversity and its success into the future is paramount and will be determined by the extent of future anthropogenic development and the impacts of climate change. At present, development has the most profound impact on the Estuary biodiversity processes through increased stormwater runoff increasing sedimentation and nutrient loads. This can lead to positive or negative feedback mechanisms (population increase or decrease) for certain estuarine species because of altered estuarine ecological processes, leading to imbalances in species diversity and the predominance of some species over others.

Human development is likely to continue which could continue the changes in biodiversity that have been occurring over the past 80 years. An increase of agricultural, urban and industrial development is likely to continue altering the Estuary’s nitrogen and sediment processes which inturn changes the distribution and health of estuarine vegetation communities and level of estuarine biodiversity. The existing biodiversity can be maintained into the future providing development is restricted and/or done in a manner that is sympathetic to the preservation of the Estuary’s biodiversity.

Future conditions of the Estuary may undergo significant changes in response to climate change and its impact on estuary processes, habitat and biodiversity. Climate change is likely to drive changes in the distribution of some plant and animal species, driving some species out of the catchment or enabling invaders to move in (CSIRO, 2007).

The natural rhythm of estuary processes throughout each season may become more profound due to an increased intensity and persistence of extremely dry or wet weather, resulting in periods where estuary processes may become significantly slower or faster. This may lead to population explosions of some species and the rapid decline of others. Over the long-term, new species not typically found within the Estuary may begin to appear while others may disappear permanently. Climate change may therefore lead to a decrease in the level of biodiversity in the Boambee/Newports Estuary and in turn alter the


overall effectiveness of Estuary processes, which may then create more pressures on biodiversity, thus creating a snowball effect.

The most dramatic impact of climate change on the Estuary would be caused by rising sea levels and the resulting inundation and increased erosion (DECC, 2008). Sea-level rise is likely to inundate coastal wetlands and alter the discharge of freshwater into estuaries, with potential adverse effects on coastal wetland habitat (CSIRO, 2007). Rising sea levels may also lead to increased acidity, increased water temperature and changes to salinity that are likely to cause widespread impacts on biodiversity within estuaries (DECC, 2008).

8.6 Biodiversity Summary

The existing level of biodiversity in the Boambee/Newports Estuary is considered high based upon the estuarine and riparian vegetation survey results and the DECCW, EPBC, Bionet and DPI Fisheries database searches.

In undertaking the survey it was expected that human interference would be evident in the form of heavy weed infestations, rubbish and general overuse of the waterways and adjacent terrestrial vegetation communities resulting in a modified landscape unable to cater for high levels of biodiversity. This was the case, but at a level much lower than was expected, especially in consideration of the Estuary being surrounded by residential, industrial and commercial development. However, as human development expands, the health and condition of the Estuary and broader catchment is expected to decline over the long-term, thus reducing habitat values that are vital to the persistence of threatened flora and fauna.

The main concerns that have arisen from the biodiversity investigation are as follows:


The presence and potential increase of pest animals as human development increases;


Increasing anthropocentric development in the catchment that may expand into the future as Coffs Harbour’s population continues to grow, potentially resulting in an increase of habitat fragmentation;

Continued commercial fishing of the Estuary may impact upon estuarine biodiversity over the long-term; and

The potential increase of rubbish throughout the catchment and upper tidal limits of mangrove forests in Boambee Creek and Newports Creek and throughout the riparian vegetation of the catchment.


9. Foreshore and Waterway Use

9.1 Introduction

The Boambee/Newports Creek catchment consists of a mixture of land uses including residential, industrial, public and private recreation, environmental protection and special uses such as schools, the university and the aerodrome. Open space and recreation reserves are also integrated along the foreshore, providing a limited development buffer to the waterway.

This chapter explores the foreshore and waterway usage and activities for the study area. The primary focus of the analysis is the waterway itself, together with the adjacent land-based facilities located on or close to the foreshore.

9.2 Foreshore and Waterway Use Study Methodology

In order to establish an understanding of the people using the Estuary, what they use it for and any existing issues or potential improvements associated with the use of the foreshore and waterway, face to face surveys were conducted on and adjacent to the Boambee/Newports Estuary foreshore. The surveys were conducted at different times of the week throughout April, May and June 2009 in order to get a cross section of participants. A total of 144 surveys were completed.

A copy of the survey questions is provided in Appendix C. Only the user profile information will be used in this Study. The other information will be used in the later stages of the Estuary Management Process.

Locations being used by residents or that had facilities (e.g. boat ramps, picnic area) were also recorded and mapped.

9.3 Description of Existing Foreshore and Waterway Use

The user survey indicates that the majority of the people using the Estuary are from the local area with 71% being from the Sawtell, Toormina and Boambee suburbs. A further 21% were from Coffs Harbour with the remaining users surveyed visiting from other LGAs, interstate or overseas.

The dominance of local users of the estuary is to be expected and was also reflected in many of the comments during the survey which indicated that “convenience” and “accessibility” was one of the main reasons for people using the Estuary.

The survey revealed that people of all ages used the Estuary. The dominant age groups were between 25-34 and 35-44 who accounted for 58% of people surveyed. This is attributed to these age groups having young families and the family friendly nature of the Estuary and the facilities.

Most people use the Estuary regularly with almost 80% visiting at least once per month and 50% visiting weekly. The most popular section of the Estuary is the lower section with 75% only visiting this part. The lower section includes the Boambee Creek Reserve and Boambee Beach. It was mainly people who fish or kayak that ventured past the lower sections of the Estuary.


The Estuary is used for a variety of recreational activities, the survey indicated that the main activities include:


Fishing Relaxing

Snorkelling Walking


Figure 9-1 shows popular locations for the above activities and they are briefly discussed below.

9.3.1 Swimming/Snorkelling

Swimming and snorkelling is one of the most popular activities in the Boambee/Newports Estuary, especially in summer. The shallow, calm water created by the sand bank at the Boambee Creek Reserve is ideal for small children and families. The deeper section of the Estuary from the rail bridge to the mouth is popular with older children and adults. This section is also a popular snorkelling location. Some spots in the mid Estuary are also popular swimming locations.

9.3.2 Recreational Fishing

The Boambee Newports Creek Estuary offers full range of fishing opportunities. Species such as bream, flathead, mangrove jack and whiting can be found in popular fishing spots such as east of the railway bridge and adjacent to Hogbin Drive. The Estuary is also a good location to source bait such as nippers.

Many users employ boats or kayaks to fish along the estuary. Activity is highest during holiday periods such as the Christmas and Easter break. There are a number of fishing clubs in Coffs Harbour which utilise the Estuary including the Sawtell Anglers Club and the Coffs Harbour Sportfishing Club.

9.3.3 BBQ’s/Picnics

The Boambee Creek Reserve is a very popular location for BBQ’s and picnics. The Reserve has numerous facilities including BBQ’s, children play ground and café. It is also provides safe swimming, fishing, snorkelling and other recreational opportunities. Some other locations along the Estuary also appear to be regularly used for family picnics.

9.3.4 Dog Exercising

Boambee Beach is the only leash free beach in the area that is accessible. This makes it a magnet for dog owners. Many of the people surveyed who visited the Estuary regularly were dog owners.

9.3.5 Relaxing

Many of the people surveyed commented on how relaxing the Estuary is. It is a place they can visit to find some peace and quiet. The undeveloped nature of the Estuary also provides a pleasant outlook that gives the impression of being out in nature.


9.3.6 Walking

Some of the people surveyed used the Estuary for walking. A few short informal walking tracks exist along banks of the Estuary but most people who use the Estuary for walking, walk down to the mouth and along Boambee Beach.

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9.3.7 Boating/Kayaking

The majority of boating activities within the estuary are related to fishing with only small to medium recreational fishing boats being used. There are three public boat ramps that are located at Boambee Creek Reserve, Hogbin Drive and Sawtell Road. Two private boat ramps exist along Boambee Creek and some informal boat access points were recorded along Cordwells Creek. The locations of the boat ramps are shown on Figure 9-1.

Non-motor water craft such as canoes, kayaks are also used frequently on the Estuary.

9.4 Predicted Future Foreshore and Waterway Use

It is predicted that Boambee/Newports Estuary will continue to be a popular location for foreshore and waterway use. In fact, with a predicted 28% growth in the population of the Mid North Coast area (DoP, 2008), the number of people using the Estuary is likely to increase. The only factor potentially reducing the number of people using the Estuary is a decrease in water quality, fish stocks or facilities.

9.5 Foreshore and Waterway Use Summary

Foreshore and waterway use will provide direction on the management of the Estuary. To establish an understanding of the people using the Estuary, what they use it for and any existing issues or potential improvements associated with the use of the foreshore and waterway, face to face surveys were conducted on and adjacent to the Boambee/Newports Estuary foreshore. These surveys were conducted at different times of the week throughout April, May and June 2009 in order to get a cross section of participants. A total of 144 surveys were completed.

Predictably, the survey indicated that the majority of the people using the Estuary are from the local area. The survey also revealed that people of all ages used the Estuary with most people using the Estuary regularly. The most popular section of the Estuary is the lower section that includes Boambee Creek Reserve and Boambee Beach.

The Estuary is used for a variety of recreational activities, the survey indicated that the main activities include:


Fishing Relaxing

Snorkelling Walking


It is predicted that Boambee/Newports Estuary will continue to be a popular location for foreshore and waterway use, with the number of people using the Estuary likely to increase. The only factor potentially reducing the number of people using the Estuary is a decrease in water quality, fish stocks or facilities.


10. Aboriginal and European Heritage

10.1 Introduction

Waterways, and water, have important spiritual and cultural significance for Aboriginal people. Many water bodies such as rivers, soaks, springs, rock holes and billabongs have Aboriginal sites associated with them. Waterways were important sources of food, such as waterfowl, tortoises, fish, rhizomes, bulbs and roots, and they were also significant trade routes and camping sites. Of special significance are the stories of the serpent-like creatures who created many rivers and wetlands. Potentially, all rivers, estuaries, wetlands and dunes could be significant Aboriginal sites – for example they could contain objects such as fishtraps or be significant for mythological or ceremonial reasons.

Waterways became a focal point for explorers and settlers with many NSW towns located near them. Waterways supply first settlers with food and drinking water, irrigation for agriculture and water for aquaculture and horticulture.

The objectives of this section include identifying and assessing indigenous and non-indigenous cultural heritage issues associated with the Boambee/Newports Estuary.

10.2 Indigenous Heritage

10.2.1 Indigenous Historical Background

The study area is located within the Gumbayngirr land. The Gumbaingirr speaking people’s territory traditionally extended over a wide area from the Clarence River to at least as far south as the Nambucca (Connell Wagner, 2004).

Today, throughout the catchment area, there are numerous Aboriginal sites, including artefacts, camp sites, stone flakes and ground-edge axes. These sites are representative of the close relationship that Aboriginal people had with the land itself and with the creatures of the land and the sea.

10.2.2 Indigenous Heritage Methodology

To assess the indigenous heritage characteristics of the Boambee/Newports Estuary, a search of available information has been undertaken. The resources reviewed includes:

Coffs Harbour Highway Planning, Coffs Harbour Section , Indigenous Heritage Assessment Working Paper No 7a , Report for NSW Roads and Traffic Authority (Connell Wagner Pty Ltd, 2004);

A report to the Coffs Harbour Shire Council on an archaeological survey in the Boambee district and North Boambee Valley (Godwin, L., 1982); and

The DECCW Aboriginal Heritage Information Management System (AHIMS).

The catchment lies within the area administered by the Coffs Harbour Local Aboriginal Land Council (LALC). In addition to the above reports, the Coffs LALC was consulted. A representative of the Coffs Harbour LALC have advised that they do not have any concerns with regards to indigenous heritage within the catchment.


10.2.3 Known Indigenous Heritage

In 1982, Godwin conducted an archaeological survey for two areas including an area bordering Boambee Creek and North Boambee Valley.

The Boambee Creek survey included a 160 ha area, which was bounded by Boambee Creek to the north and Hogbin Drive to the east (Newports Creek Bridge to the junction of Hogbin Drive and Sawtell Road). This area was well vegetated at the time of the survey.

The North Boambee Valley survey area was 640 hectares, which was located between Englands Road and the Roberts Hill ridgeline. Godwin (1982) reported that it was difficult to assess as ‘the area had been extensively changed by Europeans’. During the survey, large areas had been cleared or contained banana plantations.

The Boambee Creek survey recorded two sites of scattered stone artefacts, located on the Boambee Creek Bridge site and an Engineering works site. An additional site of significance was also found in this area, which was a good food place along Boambee Creek.

In the North Boambee Valley study area a single recorded open campsite (‘Drive-In Site’), as shown on Figure 10-1, was found in a ploughed paddock on a hill that rises 10-15 metres above surrounding marshland (Godwin, 1982). The site, estimated to contain many hundreds of stone artefacts scattered across a 5-hectare area, is the largest artefact scatter so far recorded in the Coffs Harbour district (Connell Wagner, 2004). Godwin also recorded two stone flakes on a foot slope just north of Englands Road and a single artefact on lowland at the foot of Roberts Hill ridge.

Further indigenous heritage assessments were undertaken by Connell Wagner in 2004 for the NSW Roads and Traffic Authority as part of the proposed Coffs Harbour Highway Planning Strategy. The assessments concentrated mainly around the vicinity of the two route options that are approximately 200 m west of the existing Pacific Highway. The assessment stated that the area has been subject to a range of European land uses such as grazing pastures and banana plantations, which will have compromised the survival potential of archaeological sites – ‘highly disturbed landscape that offers little potential for the preservation of in situ Aboriginal archaeological sites’. However, the assessment does report a number of specific areas where the potential for archaeological sites is moderate or high. The areas include, Roberts Hill where some isolated ground-edge axes have been reported and Englands Road where some stone artefact scatters have been found.

The AHIMS search dated 19 May 2009, has shown 58 Aboriginal objects and Aboriginal places in or near the catchment. A full list of these sites is provided in Appendix D. All Aboriginal places and Aboriginal objects are protected under the National Parks and Wildlife Act 1974 (NPW Act).

Some items listed include middens near Boambee Creek and open camp sites near Newports Creek. Possible foreshore erosion at these sites in the Estuary may damage Aboriginal middens.


10.3 Non - Indigenous heritage

10.3.1 Non- Indigenous Historical Background

On May 15, 1770 Captain James Cook sailed past the future site of Coffs Harbour and named the “Solitary Islands”. Due to the steep mountain ranges and deep river valleys, access by land to the Coffs Harbour area was very difficult in the early days of European settlement. In or about 1847 Captain John Korff in his ship “Brothers” took shelter from a storm off the southern headland of Coffs Harbour, remaining there for four days, during which time he became impressed with the safety afforded by the coastal configuration. Consequently, Captain Korff has been credited as the first European to discover the Korff’s Harbour area, now called Coffs Harbour. It is thought that the change in name from ‘Korffs Harbour’ to ‘Coffs Harbour’ was as a result of a printing error in the Government gazette.

Topography and the fact that the Coffs Harbour area did not support a major river were the principle reasons for the slow European settlement of the area. Settlement began with the discovery of rivers and creeks that provided access to the exploitable timber resources. Timber-cutter Walter Harvie is believed to be the first non-indigenous settler in the immediate Coffs Harbour District. During 1865- 1866 he established a timber camp on Coffs Harbour Creek near the present showgrounds to draw cedar from the Red Hill area. The timber was floated downstream and dragged by bullock teams across the beach before being shipped to Sydney (Connell Wagner, 2004).

In the early 1880s, the first permanent residents arrived to take up land within the gazetted town reserves at Coffs Harbour. Settlement by Europeans increased in the 1880s, as settlers overflowed from the Bellinger and Clarence River districts (CHCC, 2001). The construction of the jetty in 1892 gave a boost to the district’s employment, leading to further growth within the harbour area.

10.3.2 Non - Indigenous Heritage Methodology

To assess the non-indigenous heritage characteristics of the Boambee/Newports Estuary, a search of available information has been undertaken. The resourced reviewed includes:

Coffs Harbour Highway Planning, Coffs Harbour Section , Non-Indigenous Heritage Assessment Draft Working Paper No7b , Report for NSW Roads and Traffic Authority (Connell Wagner Pty Ltd, 2004);

Register of the National Estate;

The National Trust of Australia (NSW) Register;

The State Heritage Register;

Heritage schedules of the North Coast Regional Environmental Plan 1998; and

Coffs Harbour Local Environmental Plan 2001.

10.3.3 Non - Indigenous Heritage

Although settlers have occupied the land within the catchment since the early 1880s, most of the existing buildings are of more recent construction. As revealed by searches of the Register of the National Estate, the National Trust of Australia (NSW) Register, the State Heritage Register and heritage schedules of the North Coast Regional Environmental Plan 1998 and Coffs Harbour Local Environmental


Plan 2001, no sites or places of acknowledged historic cultural heritage significance have been identified in the catchment area.

The Connell Wagner (2004) assessment identified an item under the Coffs Harbour Coastal Landscape Heritage Study (CHCC, 1995) that possibly has heritage significance. The Coffs Harbour Coastal Landscape Heritage Study (CHCC, 1995) was undertaken to identify areas/items, which the community deemed to have landscape heritage value. This would aid in the development of planning processes within CHCC, which are capable of ensuring the long-term protection and preservation of the local coastal heritage landscape. The study identified a number of sites, which were considered worthy of inclusion on the Register of the National Estate. This study included the Roberts Hill Reserve Lookout, which is found in the upper catchment boundary west of the Pacific Highway. However, the Connell Wagner (2004) report stated that of the items listed under consideration, Roberts Hill Reserve Lookout is unlikely to be listed.

Besides the items stated above, the assessment stated no sites of non – Indigenous heritage significance were located around the vicinity of the two route options within the catchment area.

It is possible that previously unidentified sites of non-indigenous heritage significance could exist in the catchment area in the form of relics associated with past rural land use. Under the provisions of the NSW Heritage Act 1977, items which are related to the settlement of NSW which are greater than 50 years of age are defined as relics and a permit is required from the Heritage Council before disturbance of such items can take place.

10.4 Heritage Summary

Waterways, and water, have important spiritual and cultural significance for Aboriginal people. Waterways were also a focal point for explorers and settlers with many NSW towns located near them. To assess the heritage characteristics of the Boambee/Newports Estuary, a search of available information has been undertaken.

The assessment uncovered records of over 60 aboriginal artefacts and sites spread throughout the catchment. This included the largest artefact scatter so far recorded in the Coffs Harbour district which was located in the North Boambee Valley.

Although settlers have occupied the land within the catchment since the early 1880s, most of the existing buildings are of more recent construction. As revealed by the searches, no sites or places of acknowledged historic cultural heritage significance have been identified in the catchment area.


11. Conclusion and Recommendations

The catchment has been subject to intensive agricultural use in the form of banana plantations in the past. More recently, urban growth has expanded significantly and this is anticipated to continue. Despite these anthropogenic impacts, the Estuary and its associated processes are in relatively good condition.

The hydrological processes are governed by the seasonal climate in the area and typical of a WDD. Future development in the catchment and climate change are predicted to alter the hydrology of the estuary without the implementation of appropriate mitigation measures.

Water quality varies throughout the Estuary. The monitoring results have shown that the ANZECC trigger values for some parameters analysed have been exceeded at some locations. The most significant impacts on water quality are likely to be land use and sewer overflows. As the catchment develops, it is expected that these impacts will increase if mitigation measures are not implemented. Climate change is also predicted to impact the water quality in the Estuary.

The rail bridge is constricting flows at the mouth of the Estuary and creating an area of high deposition. The upper fluvial zone is also being impacted by gravel and sand beds being transported from the upper catchment. Despite these impacts, the fluvial geomorphology processes appear to have been relatively stable over the past several decades, as are the banks of the Estuary.

Likewise, the biodiversity of the Estuary is considered to be in good condition, despite some impacts from development. A range of terrestrial and estuarine wetland communities are present and most are considered to be in good condition. Salt marsh communities are indicating the most stress. The main threats to the biodiversity of the Estuary are considered to be clearing and sedimentation.

Not surprisingly, given the condition and location of the Estuary, it is a popular recreational location. Many visitors regularly use the Estuary for a range of activities. The catchment is also known to contain some items of aboriginal heritage significance.

The main concerns that have been identified by the Study and require management, include:

Inappropriate land use and development, especially in the upper catchment;

The predicted impacts of climate change;



Vegetation clearing which may lead to reduced biodiversity value and an increase in habitat fragmentation;

The large areas proposed for development within the catchment and the potential associated impacts;

Gross pollution; and

A lack of information.

It is recommended that the Estuary Management Study and Estuary Management Plan provide a range of practical and effective management actions to address these and other issues. The aim of these management actions should be to ensure the sustainable health of the Boambee/Newports Estuary.


12. References

ASSMAC (1998). Acid Sulfate Soils Manual 1998. Acid Sulfate Soil Management Advisory Committee, Wollongbar, NSW, Australia.

Australian Natural Resources Atlas (ANRA) (2007). Coasts – Understanding Processes – Australia. Viewed 19/5/09. Department of the Environment, Water, Heritage and the Arts. Accessed at: http://www.anra.gov.au/topics/coasts/processes/index.html

Bureau of Meteorology (BOM) (2009). Climate of Coffs Harbour. Viewed 5/6/09. Bureau of Meteorology. Accessed at: http://www.bom.gov.au/weather/nsw/coffs_harbour/climate.shtml

CHCC (1995). Coffs Harbour Coastal Landscape Heritage Study. Coffs Harbour City Council.

CHCC (2007). ‘Our Living City’ Settlement Strategy. Coffs Harbour City Council.

CHCC (2001). Coffs Harbour Snapshot. Coffs Harbour City Council.

CHCC (2000). Urban Stormwater Management Plan (May). Coffs Harbour City Council.

CHCC (2004). Coffs Harbour State of the Environment Comprehensive Report. Coffs Harbour City Council.

CHCC (2009) Coffs Harbour State of the Environment Comprehensive Report. Coffs Harbour City Council.

Commonwealth Scientific and Industrial Research Organisation (CSIRO) (2007). Climate Change in the Northern River Catchment. Commonwealth Scientific and Industrial Research Organisation.

Connell Wagner Pty Ltd (2004). Coffs Harbour Highway Planning, Coffs Harbour Section, Indigenous

Heritage Assessment Working Paper No 7a

Connell Wagner Pty Ltd, 2004 Coffs Harbour Highway Planning, Coffs Harbour Section , Non-Indigenous Heritage Assessment Draft Working Paper No7b , Report for NSW Roads and Traffic Authority.

Costanza, R, Kemp, M & Boynton, W (1993). Predictability, Scale, and Biodiversity in Coastal and Estuarine Ecosystems: Implications for Management. Source: Ambio, Vol. 22, No. 2/3, Biodiversity: Ecology, Economics, Policy (May, 1993), pp. 88- 96. Allen Press on behalf of Royal Swedish Academy of Sciences.

CSIRO (2007). Climate Change in the Northern Rivers Catchment. Commonwealth Science and Industrial Research Organisation, Australia.

Dalrymple, R. W., Zaitlin, B. A., and Boyd, R., (1992) Estuarine facies models; conceptual basis and stratigraphic implications. Journal of Sedimentary Petrology. 62:1130-1146.

DECC (2008). North Coast Bioregion. Viewed 13/5/2009. NSW Department of Environment and Climate Change (DECC). Accessed at:

http://www.environment.nsw.gov.au/bioregions/NSWNorthCoastBioregion.htm

Department of Environment and Climate Change (DECC) (2008). North Coast Bioregion. Viewed 13/5/2009. NSW Department of Environment and Climate Change (DECC). Accessed at: http://www.environment.nsw.gov.au/bioregions/NSWNorthCoastBioregion.htm

http://www.anra.gov.au/topics/coasts/processes/index.html�

http://www.bom.gov.au/weather/nsw/coffs_harbour/climate.shtml�

http://www.environment.nsw.gov.au/bioregions/NSWNorthCoastBioregion.htm�

http://www.environment.nsw.gov.au/bioregions/NSWNorthCoastBioregion.htm�


Department of Environment and Climate Change (DECC) (2008). Summary of Climate Change Impacts North Coast Region. NSW Climate Change Action Plan. NSW Department of Environment and Climate Change (DECC).

Department of Natural Resources (DNR) (2007). Estuaries in NSW: Boambee Creek: Estuarine Vegetation and Habitats. Viewed 13/5/09. NSW Department of Natural Resources. Accessed at: http://www.dnr.nsw.gov.au/estuaries/inventory/data/vegetation/boambee.shtml

Department of Natural Resources (DNR) (2009). Estuaries in NSW: Boambee Creek, Viewed 14/5/09. NSW Department of Natural Resources. Accessed at: http://www.dnr.nsw.gov.au/estuaries/inventory/data/limits/boambee.shtml

Department of Planning (2007). The NSW Comprehensive Coastal Assessment Toolkit. NSW Department of Planning.

Department of Planning (2008). Mid North Coast Regional Strategy. (NSW Department of Planning)

Department of Primary Industries (DPI) (NSW Fisheries) (2005). Fishnote DF/30: Saving Our Seagrasses. NSW Department of Primary Industries.

Department of Primary Industries (DPI) (NSW Fisheries) (2005). Impacts of Urban and Rural

Development. Viewed 19/5/09. Department of Primary Industries Fisheries. Accessed at: http://www.dpi.nsw.gov.au/fisheries/habitat/threats/urban

Department of Primary Industries (DPI) (NSW Fisheries) (2006) Fishnote DF/30: Our Mangrove Forests.

NSW Department of Primary Industries.

Department of Primary Industries (NSW Fisheries) (2005) Fishnote DF/29: Saving Our Seagrasses.

Fisher M., Body M. & Gill J. (1996). The Vegetation of the Coffs Harbour City Council LGA, for Coffs Harbour City Council, June 1996.

Fletcher (2004). Stormwater Flow and Quality and the Effectiveness of Non-Proprietary Stormwater Treatment Measures.

Geoscience Australia (GA) (2009). National Land and Water Resource Audit Boambee Creek condition assessment report. Viewed 14/5/09. Geoscience Australia. Accessed at: http://dbforms.ga.gov.au/www/npm.Ozcoast.show_mm?pBlobNo=9038

Godwin, L. (1982). A report to the Coffs Harbour Shire Council on an archaeological survey in the Boambee district and North Boambee Valley. Report to Coffs Harbour Shire Council.

Haines, P, Wicks, J, Richardson, D & Agnew, L (2005). Moonee Creek Estuary Processes Study. WBM Oceanics Australia. Newcastle, NSW.

Haines, P.E., Tomlinson, R.B., and Thom, B.G. (2006). Morphometric assessment of intermittently open/closed coastal lagoons in New South Wales Australia, Estuarine Coastal and Shelf Science, 67 (2006), 321-332.

Hennessy, K. Page, C., McInnes, K., Jones, R Bathols, J., Collins, D./ and Jones, D. (2004). Climate

Change in New South Wales. Part 1. Past Climate Variability and Projected Changes in Average Climate. CSIRO and BOM.

Jansen A., Robertson A., Thompson L., Wilson A. (2005) Rapid Appraisal of Riparian Condition Version 2 (RARC), River and Riparian Land Management Technical Guideline Number 4A, Canberra.

http://www.dnr.nsw.gov.au/estuaries/inventory/data/vegetation/boambee.shtml�

http://www.dnr.nsw.gov.au/estuaries/inventory/data/limits/boambee.shtml�

http://www.dpi.nsw.gov.au/fisheries/habitat/threats/urban�

http://dbforms.ga.gov.au/www/npm.Ozcoast.show_mm?pBlobNo=9038�


Kench, P. S. (1999). Geomorphology of Australian estuaries: Review and prospect, Australian Journal of Ecology, 24: 367-380.

Manly Hydraulic Laboratory (2005). DIPNR Boambee Creek Estuary Tidal Data Collection April to July

2005. Manly Hydraulic Laboratory.

Marine Parks Authority NSW (2005). Tweed-Moreton Bioregion. Viewed 13/5/2009. Marine Sanctuaries National Parks of the Sea website. Marine Parks Authority (MPA) NSW. Accessed at: http://www.marinesanctuaries.org.au/marine/index.php?option=com_content&task=view&id=47&Itemid=62

Marine Parks Authority NSW (2005). Tweed-Moreton Bioregion. Viewed 13/5/2009. Marine Sanctuaries National Parks of the Sea website. NSW Marine Parks Authority (MPA). Accessed at: http://www.marinesanctuaries.org.au/marine/index.php?option=com_content&task=view&id=47&Itemid=62

Milford, H.B. (1999). Soil Landscapes of the Coffs Harbour 1:100 000 Sheet – Department of Land and Water Conservation, Sydney.

Nichol, S. L. (1991). Zonation and sedimentology of estuarine facies in an incised valley, wave-dominated, microtidal setting, New South Wales, Australia. In: D. G. Smith, G. E. Reinson, B. A. Zaitlin and R. A. Rahmani, Classical Tidal Sedimentology, Canadian Society of Petroleum Geologists, Memoir 16: 41-58.

Northern Rivers Catchment Management Authority (NRCMA) (2008). Biodiversity. Viewed 15/5/09. NSW Government - Northern Rivers Catchment Management Authority. Accessed at: http://www.northern.cma.nsw.gov.au/programmes_biodiversity.php

NSW Government Natural Resources (2007) Estuaries in NSW, Boambee Creek Data, DPI, DoP, DNR. Accessed at: http://www.naturalresources.nsw.gov.au/estuaries/inventory/boambee.shtml on 09/08

NSW Marine Parks (2005). NSW Marine Parks: Ensuring the Future of the Marine Environment. Accessed at: http://www.marinesanctuaries.org.au/marine/index.php?option=com_content&task=view&id=47&Itemid=62 on 12/08

NSW Water Resources (1993). NSW Estuary Management Policy. NSW Government.

OzCoasts (2009). Coastal Indicators: Saltmarsh and saltflat areas. Viewed 2/6/09. OzCoasts, Australian Online Coastal Information. Accessed at: http://www.ozcoasts.org.au/indicators/changes_saltmarsh_area.jsp

OzCoasts (2009). Wave-dominated Deltas. Viewed 14/5/09. OzCoasts, Australian Online Coastal Information. Accessed at: http://www.ozcoasts.org.au/conceptual_mods/geomorphic/wdd/wdd.jsp

Price, C, Gosling, A, Westlake, M and Golus, C (2008). Wetland

Assessment Techniques Manual for Australian Wetlands Version 3.6. WetlandCare Australia, Ballina, NSW.

Queensland Department of Primary Industries and Fisheries (2009). Saltmarsh, Seagrass and Algae. Viewed 2/6/09. Queensland Department of Primary Industries and Fisheries (DPI&F). Accessed at: http://www.dpi.qld.gov.au/cps/rde/dpi/hs.xsl/28_9127_ENA_HTML.htm

http://www.marinesanctuaries.org.au/marine/index.php?option=com_content&task=view&id=47&Itemid=62�




http://www.northern.cma.nsw.gov.au/programmes_biodiversity.php�

http://www.naturalresources.nsw.gov.au/estuaries/inventory/boambee.shtml on 09/08�



http://www.ozcoasts.org.au/indicators/changes_saltmarsh_area.jsp�

http://www.ozcoasts.org.au/conceptual_mods/geomorphic/wdd/wdd.jsp�

http://www.dpi.qld.gov.au/cps/rde/dpi/hs.xsl/28_9127_ENA_HTML.htm�


Ryan, Heap, Radke and Heggie (2003). Conceptual Models of Australia’s Estuaries and Coastal Waterways, Applications for Coastal Resource Management. CRC for Coastal Zone, Estuary and Waterway Management, Geoscience Australia & Department of Geography and Environmental Studies.

Roy, P. S., Williams, R. J., Jones, A.R., Yassini, I., Gibbs, P.J., Coates, B., West, R.J., Scanes, P.R., Hudson J.P. and S. Nichol (2001). Structure and Function of South-east Australian Estuaries, Estuarine, Coastal and Shelf Science, 53(3), 351-384.

Roy, P.S., (1994). Holocene estuary evolution—stratigraphic studies from southeastern Australia. vol. 51. Society for Sedimentary Petrology.

Sawtell, S (2002). An Analysis of Ecological Change in Relation to Human Settlement Patterns and

Activities in Estuaries in the Coffs Harbour Region, NSW Australia. Masters Thesis undertaken by Stephen Sawtell through University of New England, Armidale NSW.

Scotts, D (2003). Key Habitats and Corridors for Forest Fauna. Occasional Paper 32. NSW National Parks and Wildlife Service.

Sloss, C., (2001). Holocene stratigraphic evolution and recent sedimentological trends, Lake Illawarra, NSW. Unpublished BSc Honours Thesis, School of Geoscience, University of Wollongong.

Stewart, M & Fairfull, S (2008). Primefact 746: Mangroves. NSW Department of Primary Industries (DPI) (NSW Fisheries).

Visit Coffs Harbour (2009). (http://www.visitcoffsharbour.com/coffsharbour/history.html), accessed 15 May 2009.

WBM (2005). Moonee Creek Estuary Processes Study. WBM.

Zaitlin, B.A., Dalrymple, R.W. and R. Boyd (1995). The Stratigraphic Organization of Incised-Valley Systems Associated with Relative Sea-Level Change. In: Incised-valley Systems: Origin and Sedimentary Sequences. Oklahoma, USA, Society of Sedimentary Geology. SEPM Special Publication No. 51: 45-62.

http://www.visitcoffsharbour.com/coffsharbour/history.html�

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