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Transcript of 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
• 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
IUCN: "a just world that values and conserves nature"
The case study area
IUCN: "a just world that values and conserves nature"
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
IUCN: "a just world that values and conserves nature"
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
IUCN: "a just world that values and conserves nature"
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
IUCN: "a just world that values and conserves nature"
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
IUCN: "a just world that values and conserves nature"
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
IUCN: "a just world that values and conserves nature"
IUCN: "a just world that values and conserves nature"
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
IUCN: "a just world that values and conserves nature"
What the re-optimization project intends to do or add
IUCN: "a just world that values and conserves nature"
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
IUCN: "a just world that values and conserves nature"
Conclusion
IUCN: "a just world that values and conserves nature"
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
IUCN: "a just world that values and conserves nature"
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
1a. Stakeholder ID, kickoff, define ecosystem goals
1b. Background work:IHA; summary report
1c. Flows Workshop
1. Estimate flow requirements
2. Determine influence of human activities
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
1a. Stakeholder ID, kickoff, define ecosystem goals
1b. Background work:IHA; summary report
1c. Flows Workshop
1. Estimate flow requirements
2. Determine influence of human activities
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
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
Key
Dry Year
Avg Year
Wet Year
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
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
• Disperse tree seeds• Transport fish larvae
• Flush woody debris from floodplain to channel
• Floodplain access for fish• Fish passage past NSBLD
1a. Stakeholder ID, kickoff, define ecosystem goals
1b. Background work:IHA; summary report
1c. Flows Workshop
1. Estimate flow requirements
2. Determine influence of human activities
Solutions
3. Identify opportunities and incompatibilities for
flow implementation
PreliminaryFlow Requirements
5a. Implement flows
Opportunities
4. Collaborative dialogue to search for solutions;
Modeling and research
Incompatibilities
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
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
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
1a. Stakeholder ID, kickoff, define ecosystem goals
1b. Background work:IHA; summary report
1c. Flows Workshop
1. Estimate flow requirements
2. Determine influence of human activities
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
PreliminaryFlow Requirements
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.