Transcript NHI-IUCN-TNC Presentation

Tools and Techniques for Re-Optimizing Major
Water Management Systems to Restore Aquatic
Ecosystems and Human Livelihoods
Presented by
The Natural Heritage Institute, IUCN, and the Nature Conservancy
IUCN World Conservation Congress – Barcelona
October 9, 2008
Agenda
• 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
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
China
Rest of Asia
North America
Western Europe
Africa
Eastern Europe
South America
Central America
Australia
Number of Large Dams
Purposes of 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.
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
Hydropower
Irrigation Water Supply
Flood Control
& Ecosystem
+ Livelihood
Restoration
The goal is enhancement of benefits, not reallocation.
Balancing the Restoration Flow
Demand and Supply Equation
Water management
techniques to generate
water when, where and
in amounts desired
Objectives:
Instream Conditions,
Floodplain Conditions
Parameters:
Magnitude, Duration,
Frequency, Location,
Seasonality
Flow Restoration Provides Greatest Benefits to:
Broad Alluvial Floodplains
Wetlands
Estuaries
Deltas
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-KomaduguYobe-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
Nigeria; Niger
& Other LCBC
States/Nations
IUCN: "a just world that values and conserves nature"
The case study area - 2
• The KYB, covering an area of about 148,000
6
km2 of the semi-arid to arid sub-catchment of
Lake Chad Basin, comprising north eastern
Nigeria and south eastern Niger
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10
12
14
FMWR-IUCN-KOMAGUDUYOBE BASIN PROJECT
C HA
D
Niger
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14
L. Chad
R.Yob e
jia
ade
'are
ma
Ja
R.
Ga
na
H
er
ma
gu
du
• The main river sub-systems are the Yobe
and the Komadugu, with the Yobe subsystem further divided into Hadejia River and
Jama’are River sub-systems
Riv
Ko
HADEJIA BARRAGE
12
12
KRIP I
KR IP II
CHALLAWA GORGE DAM
TIG A DAM
ERO
ON
N
R
.B
CA M
un
ga
KAFIN ZAKI DAM (PROPOSED)
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10
Legend
Major rivers
• 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"
Nigeria
0
Major Dams
Bas in boundary
200 Miles
International boundary
Prod uced by Afre me dev C onsu ltancy Service s Ab uja. March 20 06
6
8
10
12
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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 managementrelated 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 decisionmaking 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
Upstream
Upstream
Damming
Damming
Downstream
Most River Systems:
Gaining River
IUCN: "a just world that values and conserves nature"
Downstream
The KYB Case:
Losing River
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
Growing Population
Growing Economy
Finite Amount of water in the hydrological cycle
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
IUCN: "a just world that values and conserves nature"
Developing and Implementing
Environmental Flows:
The Savannah River (Georgia, USA)
Jeff Opperman
The Nature Conservancy
October 9, 2008
The Savannah River Basin
• Flood control
• Hydropower
• Water supply
Total Drainage Basin Area -10580 sq miles
Thurmond Dam
Russell Dam
Hartwell Dam
1900
1950
2000
1. Estimate flow requirements
1a. Stakeholder ID, kickoff,
define ecosystem goals
1b. Background work:
IHA; summary report
2. Determine influence
of human activities
1. Estimate flow requirements
1a. Stakeholder ID, kickoff,
define ecosystem goals
1c. Flows Workshop
1b. Background work:
IHA; summary report
2. Determine influence
of human activities
Environmental Flow Workshop Structure
Flood
Shoals
High Pulse
Low Flow
Full Group
Floodplain
Estuary
EFRs for:
• Dry years
• Average years
• Wet years
Flood
Unified Flood
High Pulse
Unified High
Low Flow
Unified Low
Flood
Defined by:
• Magnitude
• Frequency
• Timing
• Duration
• Rate of change
High Pulse
Low Flow
1. Estimate flow requirements
1a. Stakeholder ID, kickoff,
define ecosystem goals
1c. Flows Workshop
1b. Background work:
IHA; summary report
2. Determine influence
of human activities
Floods
Preliminary
Flow Requirements
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
>30,000 cfs; 5 pulses, >2 days with 2 events
of 2 week duration (March and early April)
High Flow
Pulses
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
<13,000 cfs; 3 successive years, every 10-20 years
• Floodplain tree recruitment
8,000-12,000 cfs;
• Exchange water with oxbows
>8,000 cfs
• Larval drift for pelagic spawners
Low Flows
<5,000 cfs
• Adequate floodplain drainage
• Create shallow water habitat for small-bodied fish
Key
Wet Year
Avg Year
Dry Year
3,000 cfs; 3 successive years every 10-20 years
• Floodplain tree recruitment
JAN
FEB
MAR
APR MAY
JUN
JUL
AUG
SEP
OCT NOV
DEC
Environmental Flow Recommendations
Savannah River, USA (below Thurmond Dam)
Floods
Details:
20,000-40,000 cfs; 2-3 days, 1/month
Purposes:
• 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
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
>30,000 cfs; 5 pulses, >2 days with 2 events
of 2 week duration (March and early April)
High Flow
Pulses
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
<13,000 cfs; 3 successive years, every 10-20 years
• Floodplain tree recruitment
8,000-12,000 cfs;
• Exchange water with oxbows
Low Flows
>8,000 cfs
• Larval drift for pelagic spawners
<5,000 cfs
• Adequate floodplain drainage
• Create shallow water habitat for small-bodied fish
Key
3,000 cfs; 3 successive years every 10-20 years
• Floodplain tree recruitment
Wet Year
Avg Year
Dry Year
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
1. Estimate flow requirements
1a. Stakeholder ID, kickoff,
define ecosystem goals
1c. Flows Workshop
1b. Background work:
IHA; summary report
2. Determine influence
of human activities
Floods
Incompatibilities
Preliminary
Flow Requirements
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
3. Identify opportunities
and incompatibilities for
flow implementation
>30,000 cfs; 5 pulses, >2 days with 2 events
of 2 week duration (March and early April)
4. CollaborativeHigh Flow
Pulses
dialogue to search for solutions;
Modeling and research
Solutions
5a. Implement flows
<13,000 cfs; 3 successive years, every 10-20 years
• Floodplain tree recruitment
8,000-12,000 cfs;
5b. Research and • Exchange
water with oxbows
monitoring>8,000
of cfsflows
Low Flows
• Larval drift for pelagic spawners
<5,000 cfs
• Adequate floodplain drainage
• Create shallow water habitat for small-bodied fish
Key
3,000 cfs; 3 successive years every 10-20 years
• Floodplain tree recruitment
Wet Year
Avg Year
Dry Year
Opportunities
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
JAN
FEB
MAR
APR MAY
JUN
JUL
AUG
SEP
OCT NOV
DEC
Implementing and monitoring high flow pulses on the Savannah
1. Estimate flow requirements
1a. Stakeholder ID, kickoff,
define ecosystem goals
1c. Flows Workshop
1b. Background work:
IHA; summary report
2. Determine influence
of human activities
Incompatibilities
Preliminary
Flow Requirements
3. Identify opportunities
and incompatibilities for
flow implementation
4. Collaborative
dialogue to search for solutions;
Modeling and research
Opportunities
Solutions
5a. Implement flows
5b. Research and
monitoring of flows
Refined Ecosystem
Flow Requirements
6. Adaptive management and
institutional/policy adaptations
Savannah River
2004-2008
 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.
Rapid Evaluation Tool for Reoptimization Potential of Hydropower Reservoirs
No
Does the facility generate power at the dam site
(rather than by diversion of water to downstream or transbasin powerhouse)?
Yes
ENVIRONMENTAL BENEFITS
No
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?
Yes
Not a high priority for
reoperation.
No
STORAGE VS. RUN-OF-RIVER
Is the active storage capacity of the reservoir more than 25% *
of the mean annual inflow?
Yes
No
Can land uses in the down-stream floodplain be modified/ managed to
accommodate controlled flood events?
Yes
Is the dam one of a complex or cascade of hydropower dams in the same basin?
No
Are there alternative sources
of thermal power in the
existing grid that can
supplant some fraction of
hydropower during seasonal
low runoff periods?
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
Are other dams in
the cascade
operated by the
same power
company?
No
Yes
Yes
Consider Rescheduling
Hydropower Generation &
Source Shifting as
reoperation strategies
*
Consider Power Grid
Interconnection as a
reoperation strategy
Provisional figure depending on local conditions.
Consider coordinated
basin wide reoperation of
the dam complex or
cascade
No
Not a high priority for
reoperation.
11
8
9
Wetland #2
Orchard
10
12
Annual crops
Wetland #1
7
“Catville”
Native Comm.
5
6
“Dogville”
Endangered Species Habitat
3
Delta
2
Artist: Lisa McCarrel
1
Numbers for dams correspond to numbers on Dam Stats table.
4
CONCLUSIONS & DISCUSSION
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