DAM RE-OPERATION:
SENEGAL RIVER CASE STUDY
Andrew Judd
CE 397 – Transboundary Water Resources
University of Texas
November 3, 2005
Potential Benefits
& Costs of Dams
Benefits
Costs
Hydropower
Planning & Design
Irrigation
Construction
Urban Water Supply
Operation & Maintenance
Flood Protection
Resettlement
Navigation
Social
Recreation
Environmental Health
Circumstances for Re-operation
•Unforeseen issues and impacts
•Change in culture, policy, technology, economy
•Mismanagement
Issue: Existing Dam operation not at optimal level
Resolution: Change existing dam operation system
to achieve more optimal (beneficial) or less harmful
results
Dam Re-operation Process
•Re-cognition of deficiency
•Re-assessment of benefits and costs
•Re-view management procedure
•Re-commendation for optimization
•Re-vise operation strategy
•Re-alization of increased benefits
Examples of Re-operation
Strategy
Outcome
Offstream Storage
Riparian Habitat Restoration
Operation Coordination
More Natural Flow Regime
Flood Easements
Sediment Transport
Power Source Shifting
Environmental Flows
Controlled Flooding
Ecosystem Restoration
Senegal River: Hydrology
Flow supplied by
upper basin precip.
Upper: ~2000mm/yr
Lower: <500mm/yr
Wet and Dry Season
Wet: April-October
High Water: July-October
Low Water: Nov-April
Bafing
Bafing Tributary
~50% of Flow in
Senegal River
Source: http://www.waterandnature.org/flow/cases/Senegal.pdf
Senegal River: Population
~2 million people
live in the Senegal
Basin
~85% depend on
the river for
subsistence
Agriculture
•Farming: Irrigation based and floodplain recession
•Fishing: Riverbed, delta, floodplain
•Livestock: Mostly nomadic grazing in floodplain pastures
Source: http://www.unesco.org/water/wwap/case_studies/senegal_river/senegal_river.pdf
All sectors depend on river system (not just water) for production
Senegal River: Development
1972-73 major drought in basin
1972 Mauritania, Mali, Senegal
convene to form Organisation
pour la mise en valeur du fleuve
Sénégal (OMVS)
Propose economic and resource
development through
construction of Manantali and
Diama Dams
Drought in Senegal
Source: http://us.oneworld.net/article/view/114123
Diama Dam
Finished in 1986
Purpose: Provide barrier to
saltwater intrusion, supply for
irrigation projects, navigation
Source: http://www.omvs.org/fr/realisations/diama.php
Source: http://www.unesco.org/water/wwap/case_studies/senegal_river/senegal_river.pdf
Manantali Dam
Finished in 1988
Purpose: Hydropower
Generation, Irrigation
Supply, Flood Control,
Navigation
Source: http://www.omvs.org/fr/realisations/diama.php
Source: http://www.unesco.org/water/wwap/case_studies/senegal_river/senegal_river.pdf
River as a Resource
Variable flow conditions provide a somewhat balanced
cycle for different sectors of agriculture and natural
ecosystems
High Flows
Fish spawning, Sediment
transport, Soil saturation,
Riverine vegetation control
Lower Flows
Recession agriculture,
Animal grazing,
Dry Season
Species control
Changes in the River’s flow
regime cause changes in
the entire River system
Impact of Dams
Objective of Dams to increase production, income and
quality of life of people of Senegal
Dam Benefits
Issue
Hydropower
Production started 2002, 10 years behind
Navigation
Navigation facilities still incomplete
Irrigation
Resources lacking to implement,
Importing rice cheaper
Water Availability
Salinity Control
Invasive species (birds, plants, bugs)
water-borne disease outbreaks
Other Issues:
•Smaller floods + dams decrease production = less income
•Conversion of society from self-sufficient to wage labor based
•But, not as dependent on river for production
Existing Management
Managing Organization: OMVS
Management Philosophy (generalized):
Equal distribution of benefits and costs of Senegal River
development throughout Mali, Senegal, and Mauritania
•Cooperative ownership
•Water allocation not
state-based
•Divided amongst
several sectors:
agriculture, inland fishing, livestock
raising, fish farming, tree farming,
fauna and flora, hydroelectric energy
production, urban and rural drinking
water supply, health, industry,
navigation, the environment
Re-operation Management
1997 Global Environmental Facility (GEF) project
–Develop more effective/comprehensive management strategy
–Include environmental issues
–Increase stakeholder involvement
2002 Senegal River Water Charter
–Procedures for water allocation
–New water projects
–Environmental Protection
–Stake-holder Participation
Change in management strategy
–Mainly facilitated by foreign involvement (NGO’s, World Bank, et al.)
–Studies of impacts to population and environment
–Communication to OMVS of issues and potential solutions
–Funding to implement environmental management projects
Re-operation Strategies
Controlled Flood
•Continuation and improvement of
irrigation “transition” flooding
•Restoration of floodplain ecosystems
–Increase fish population
–Improve grazing and farmland
–Provide habitat for bird migration
–Control invasive species
–Improve quality of life of local
stakeholders
•Recognition of value of natural
environment and traditional livelihood
practices
Source: http://edcintl.cr.usgs.gov/senegalfeature/air.html
Lessons Learned
•All potential factors and impacts
considered in project cost benefit
analysis
•Local stakeholder involvement
required for project to provide
benefit to
•Greater flexibility needed in
management strategies to achieve
optimal system
Discussion Question:
With the implementation of re-operation
projects, regulation and management agencies tend to support operation
strategies that have very specific definitions of water allocation volumes
and water quality levels. However, river systems tend to react more
favorably to a more flexible operation strategy. Through what means can
these two opposing management strategies be combined to produce
more effective water resource re-operation plans?