Tools and Techniques for Re-Optimizing Major Water Management Systems to Restore Aquatic Ecosystems...

Tools and Techniques for Re-Optimizing Major

Water Management Systems to Restore Aquatic Ecosystems and

Human Livelihoods

IUCN World Conservation Congress – BarcelonaOctober 9, 2008

Presented by The Natural Heritage Institute, IUCN, and the Nature Conservancy

http://www.nature.org/?src=logo

• Introduction– Impacts of major water management systems – Dam re-optimization

• Case studies– Komodugu Yobe Basin Nigeria

(Presented by Daniel K. Yawson, IUCN) – Savannah River:

(Presented by Jeff Opperman, TNC)

• REOP Group Exercise– Introduction to the Rapid Evaluation Tool for

Reoptimization Potential (or REOP tool) of Hydropower Reservoirs

– Conduct the group exercise

• Feedback and Conclusions

Agenda

Extent of Major Dams• 1949: 5,000 large dams,

1/4 in developing countries

• 2008: 49,000 large dams, 2/3 in developing countries

• Over the past two decades, the pace of dam building has declined in North America and Europe, where most of the technically attractive sites have already been developed.

• 1,700 large dams are under construction outside of North America and Europe, primarily China and India.

Location & Distribution of Major Dams At end of 20th Century

ChinaRest of Asia

North AmericaWestern Europe

AfricaEastern EuropeSouth America

Central AmericaAustralia

Number of Large Dams

Irrigation: Half the world’s large dams were built exclusively or primarily for irrigation.

Hydropower: Hydropower currently provides 19% of the world’s total electricity supply and is used

in over 150 countries.

Flood Control: Floods affect the lives of 65 million people per year—more than any other type of disaster, including war, drought, and famine.

Purposes of Dams

Physical Transformation of Rivers

Large dams alter flows and natural processes by:

• Reducing flow during natural flood periods• Increasing flow during dry periods• Fragmenting the river system• Disconnecting rivers from floodplains, wetlands,

deltas, and estuaries

Impact of Dam Operations on Natural Flow Patterns

This is the same volume!

Impact of Dam Operations on Floodplains

Effects on Downstream Livelihoods

• Dams alter productive floodplains that support agriculture, the harvest of forest products, herding, and fishing (a critical source of protein for over 1 billion people).

• “These social and environmental impacts are often disproportionately borne by poor people, indigenous people and other vulnerable groups.”

• “. . . dams frequently entail a reallocation of benefits from local riparian users to new groups of beneficiaries at a regional or national level.”

WCD, 2000.

Benefits of Reoptimizing Dam Operations

The goal is enhancement of benefits, not reallocation.

+

Parameters: Magnitude, Duration,

Frequency, Location,

Seasonality

Objectives:Instream Conditions,Floodplain Conditions

Water management techniques to generate water when, where and in amounts desired

Balancing the Restoration Flow

Demand and Supply Equation

Flow Restoration Provides Greatest Benefits to:

Broad Alluvial Floodplains

Estuaries Deltas

Wetlands

Reoptimize Dam Operations

• Create a flow pattern that more closely mimics the natural variability in flows.

• Convert dams to “run-of-the-river” operations, re-creating an annual artificial flood.

• Recharge the aquifer.

• Facilitate climate change adaptation.

• Re-operate the entire water management system—not just the storage component.

Objectives

• Devise and demonstrate tools and techniques that can be applied major dams everywhere

• Much improved sense of environmentally compatible siting, design and operations of new dams

• Durable network of expertise and activism

• Reduce risks associated with climate change

Next, case studies…

Why re-optimizing the Tiga and Challawa Gorge dams to restore

human livelihoods and ecosystems in the Hadejia-Jama’are-Komadugu-

Yobe-Lake Chad Basin?

Presented by

Daniel Kwesi YAWSON, Ph.D.

(Project Coordinator, IUCN-KYB Project)

IUCN: "a just world that values and conserves nature"

Outline of the Presentation

• The case study area

• The threats and the challenges

• What to do to address challenges

• What has been done so far (to date)

• What the re-optimization project intends to do or add


The case study area


Nigeria; Niger & Other LCBC States/Nation

s

The case study area - 2• The KYB, covering an area of about 148,000 km2 of the semi-arid to arid sub-catchment of Lake Chad Basin, comprising north eastern Nigeria and south eastern Niger

• The main river sub-systems are the Yobe and the Komadugu, with the Yobe sub-system further divided into Hadejia River and Jama’are River sub-systems

• Some 15 million people depend directly or indirectly on the resources of the river, which sustains the livelihood of the majority through recession agriculture, pastoralism, fisheries activities, etc.

• As a shared resource, water is a potential source of conflict (e.g. farmers versus herders), but also a key state and regional integrating factor


Niger

Nigeria

KAFIN ZAK I DA M (PR O PO SED )

TIG A DAM

CH ALLAW A G O RG E D AM

KRIP I

KR IP II

HAD EJIA BAR RA GE

R.Yob e

Kom

agud

u Ga

na

River H

adejia

R.B

unga

R.Jam

a'are

CH

AD

CA

ME

RO

ON

0 200 Miles

N

FMWR-IUCN-KOMAGUDUYOBE BASIN PROJECT

L. Chad

Produced by Afremedev Consultancy Services Abuja. March 2006

Legend

Major rivers

Major Dams

Basin boundary

International boundary

6

6

8

8

10

10

12

12

14

14

10 10

12 12

14 14

The threats and the challenges• Fast-growing water demand and inequitable access to water resources

• Fragmented regulatory responsibilities

• Lack of reliable hydro-meteorological information

• Uncoordinated development interventions

• Growing tensions and risks of conflicts

• Reduced river flow due to climate variability and change

• Environmental degradation


What to do to address challenges

• (long-term): an integrated development of the land, water and living resources of the basin so as to promote their sustainable use, conservation and equity

• (medium-term): fairer and more judicious allocation of water resources between competing sectors and the regions e.g. re-optimization of the large dams in the basin to satisfy downstream users as well

• (short-term): the clarification and strengthening of water management-related rules and regulations

• (short-term): the establishment of a regulatory body at the basin level

• (short-term): the establishment of a platform for weighing competing water demands


What to do to address challenges - 2

• (short-term): establishment of an institutional framework for decision-making at the basin

•(short-term): improvement of data quality and availability, which required first that existing information base be compiled, rescued, synthesized, updated, and gaps identified and filled

•(short-term): a Grand Vision and an Water Management Plan for the basin

•(short-term): need for a common understanding of the basin-level big picture issues among stakeholder groups


What has been done so far (to date)

• Socio-economic & environment study and comprehensive water audit to facilitate dialogue

• Development of Catchment Management Plan with the establishment of a Trust Fund to actualize the Plan

• About to be signed “Water Charter” to regulate the resource

• Some pilot activities to demonstrate best practices

By and large, the short-term challenges are under control by way of improving the institutional framework of land and water management in the basin


What the re-optimization project intends to do or add


Most River Systems:Gaining River

Damming

Upstream

Downstream

The KYB Case:Losing River

Damming

Upstream

Downstream

What the re-optimization project intends to do or add - 2

• To address the medium- to long-term challenges

• Using run-of-the-river approach (as much as possible) to maintain or revive the floodplain activities and the wetlands sustenance (i.e. by way of ecosystem assessments). Thus, operating more as a run-of-the river facility and less as a storage facility

• To alter downstream ecology, sediment effects and affecting freshwater ecosystems to as much as possible to pre-dam construction era

• Surface water-groundwater conjuncture use

• Having the stakeholders in the project activities and they are to propose and select the planning model for the basin


Conclusion


Finite Amount of water in the hydrological cycle

Growing EconomyGrowing Population

Increasing Demand for water

Increased Competition for scarce water

Need for equitable allocation and conflict resolution


With Actualization of Project

Developing and Implementing Environmental Flows:

The Savannah River (Georgia, USA)

Jeff OppermanThe Nature Conservancy

October 9, 2008

Total Drainage Basin Area -10580 sq miles

The Savannah River Basin The Savannah River Basin

• Flood control• Hydropower• Water supply

Thurmond Dam Russell Dam

Hartwell Dam

1900 1950 2000

1a. Stakeholder ID, kickoff, define ecosystem goals

1b. Background work:IHA; summary report

1. Estimate flow requirements

2. Determine influence of human activities



1c. Flows Workshop



Environmental Flow Workshop Structure

Full Group

Shoals

Floodplain

Estuary

Flood

High Pulse

Low Flow

Flood

High Pulse

Low Flow

Flood

High Pulse

Low Flow

Defined by:• Magnitude• Frequency

• Timing• Duration• Rate of change

Unified Flood

Unified High

Unified Low

EFRs for:• Dry years• Average

years• Wet years



1c. Flows Workshop



PreliminaryFlow Requirements

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Low Flows

High FlowPulses

Floods

3,000 cfs; 3 successive years every 10-20 years• Floodplain tree recruitment

<5,000 cfs• Adequate floodplain drainage

• Create shallow water habitat for small-bodied fish

>8,000 cfs• Larval drift for pelagic spawners

50,000-70,000 cfs; 2 weeks, avg every 2 yrs• Maintain channel habitats

• Create floodplain topographic relief• Provide fish access to the floodplain

• control invasive species• Maintain wetlands and fill oxbows and sloughs

• Enhance nutrient cycling & improve water clarity• Disperse tree seeds

<13,000 cfs; 3 successive years, every 10-20 years• Floodplain tree recruitment

8,000-12,000 cfs;• Exchange water with oxbows

20,000-40,000 cfs; 2-3 days, 1/month• Provide predator-free habitat for birds

• Disperse tree seeds• Transport fish larvae

• Flush woody debris from floodplain to channel• Floodplain access for fish• Fish passage past NSBLD

>30,000 cfs; 5 pulses, >2 days with 2 eventsof 2 week duration (March and early April)

Key

Dry Year

Avg Year

Wet Year


Low Flows

High FlowPulses

Floods















Key

Dry Year

Avg Year

Wet Year

Key

Dry Year

Avg Year

Wet Year


Low Flows

High FlowPulses

Floods















Key

Dry Year

Avg Year

Wet Year

Environmental Flow RecommendationsSavannah River, USA (below Thurmond

Dam) Details:20,000-40,000 cfs; 2-3 days,

1/monthPurposes:

• Provide predator-free habitat for birds


• Flush woody debris from floodplain to channel

• Floodplain access for fish• Fish passage past NSBLD



1c. Flows Workshop



Solutions

3. Identify opportunities and incompatibilities for

flow implementation


5a. Implement flows

Opportunities

4. Collaborative dialogue to search for solutions;

Modeling and research

Incompatibilities


Low Flows

High FlowPulses

Floods















Key

Dry Year

Avg Year

Wet Year


Low Flows

High FlowPulses

Floods















Key

Dry Year

Avg Year

Wet Year

Key

Dry Year

Avg Year

Wet Year

5b. Research and monitoring of flows

Implementing and monitoring high flow pulses on the Savannah

6. Adaptive management and institutional/policy

adaptations



1c. Flows Workshop



5a. Implement flows

Opportunities

4. Collaborative dialogue to search for solutions;

Modeling and research

Incompatibilities

5b. Research and monitoring of flows

Solutions

3. Identify opportunities and incompatibilities for

flow implementation


Refined Ecosystem Flow Requirements

Savannah River2004-2008

E-flows defined <1 year; $90,000US

Changed reservoir operations

e-flows partly implemented helping guide real-time

reservoir operations

Monitoring & research to support adaptive

management river, floodplain, estuary

Modeling HEC-ResSim, HEC-EFM

Redefined the engineer-scientist relationship

Rapid Evaluation Tool for Reoptimization Potential

(REOP tool)

What is the REOP tool?

What is its purpose & scope?

Does it target particular dams?

REOP Exercise

• Instructions: Using the information sheet & watershed sketch as a

guide, apply the REOP tool to determine which dams are candidates for reoptimization.

If a “NO” answer is achieved, cross off that dam and continue to the next one.

If a “YES” answer is achieved, move to the next level of the REOP decision-tree until the dam is eliminated or is determined to be a promising candidate.

Not a high priority for

reoperation.

Is the active storage capacity of the reservoir more than 25% *

of the mean annual inflow?

Does the dam control flows affecting floodplains, riparian zones, wetlands, deltas or estuaries that are productive for food production or ecosystem processes or would environmental flows within the downstream channel

restore socially valued or endangered species?

Does the facility generate power at the dam site (rather than by diversion of water to downstream or

transbasin powerhouse)?

Are there alternative sources of thermal

power in the existing grid that can supplant

some fraction of hydropower during seasonal low runoff

periods?

Consider Rescheduling Hydropower

Generation & Source Shifting as reoperation strategies

Consider Power Grid

Interconnection as a reoperation

strategy

Consider coordinated basin wide reoperation of the dam complex or

cascade

Can land uses in the down-stream floodplain be modified/ managed to accommodate controlled flood events?

Yes

Yes

No

Yes

Rapid Evaluation Tool for Reoptimization Potential of Hydropower Reservoirs

Is the dam one of a complex or cascade of hydropower dams in the same basin?

Are other dams in the

cascade operated by

the same power

company?

Yes

No

Not a high priority for

reoperation. No

Yes

Yes

No

Are there alternative sources of thermal power in adjacent

grids that can supplant some

fraction of hydro-power during

seasonal low runoff periods?Yes

No

No

Yes

* Provisional figure depending on local conditions.

STORAGE VS. RUN-OF-RIVER

ENVIRONMENTAL BENEFITS

No

No

1

2

3

4

5

6

7

8

9

10

11

12

“Dogville”

“Catville”

Endangered Species Habitat

Numbers for dams correspond to numbers on Dam Stats table.

Wetland #2

Wetland #1

Native Comm.

Annual crops

Orchard

Delta

Artist: Lisa McCarrel

CONCLUSIONS & DISCUSSION


Thank you for your participation.

Please remember to sign the workshop roster with your name & e-mail addresses.

We follow-up after the conference.


Tools and Techniques for Re-Optimizing Major Water Management Systems to Restore Aquatic Ecosystems...

Documents

Transcript of Tools and Techniques for Re-Optimizing Major Water Management Systems to Restore Aquatic Ecosystems...