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?