dam re-operation: senegal river case study andrew judd ce 397 – transboundary water resources...
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DAM RE-OPERATION:SENEGAL RIVER CASE STUDY
Andrew JuddCE 397 – Transboundary Water ResourcesUniversity of TexasNovember 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 StorageRiparian 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 Tributary
~50% of Flow in Senegal River
Source: http://www.waterandnature.org/flow/cases/Senegal.pdf
Bafing
Senegal River: Population
Source: http://www.unesco.org/water/wwap/case_studies/senegal_river/senegal_river.pdf
~2 million people live in the Senegal Basin
~85% depend on the river for subsistenceAgriculture•Farming: Irrigation based and floodplain recession•Fishing: Riverbed, delta, floodplain•Livestock: Mostly nomadic grazing in floodplain pastures
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 SenegalSource: 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 DamFinished in 1988
Purpose: Hydropower Generation, Irrigation Supply, Flood Control, Navigation
Source: http://www.unesco.org/water/wwap/case_studies/senegal_river/senegal_river.pdf
Source: http://www.omvs.org/fr/realisations/diama.php
River as a ResourceVariable 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 DamsObjective of Dams to increase production, income and quality of life of people of Senegal
Dam Benefits Issue
HydropowerProduction started 2002, 10 years
behind
Navigation Navigation facilities still incomplete
IrrigationResources lacking to implement,
Importing rice cheaper
Water Availability Invasive species (birds, plants, bugs) water-borne disease outbreaksSalinity Control
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 ManagementManaging 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 Management1997 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 StrategiesControlled 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?