Reservoir management

• Lecture Outline

– Human engineered habitats

– Physical environment

– Native and nonnative fishes

• Assignments

• pp. 285 - 320 (IFM)

Why build reservoirs?

1) Hydroelectric power

2) Flood control

3) Water storage

4) Irrigation

5) Power plant cooling

6) Water supply

7) Navigation

Where Do Reservoirs Occur?

1) Globally: 2/3 of freshwater flowing to the ocean is obstructed by approximately 40,000 large dams (> 15 m in height) and more than 800,000 smaller dams

2) North America: concentrated in areas with few natural lakes (i.e., unglaciated areas)

3) Within watersheds: narrow river channels with steep gradient

When were reservoirs built?

Reservoirs are “hybrids” between rivers and lakes

Shoreline Development Index

Storage Ratio (Turnover)

1) Storage Ratio (Turnover)

a) Reservoir volume / annual discharge

2) Examples

a) Dale Hollow Lake, TN = 1.16

b) Fort Peck, MT = 2.36

c) Grandby Reservoir, CO = 3.00

d) Texoma, OK-TX = 1.1

Hypsographic Curve

Development of Reservoir Fish Assemblages

Reservoirs Disrupt Natural River Continuum

Reservoirs Fish Assemblages

Reservoirs are complex systems

Nutrient Upsurge

Largemouth Bass, Clinton Reservoir, Kansas

West Point Reservoir, Alabama

1) Lake Texoma

a) Decrease in number of species

b) Appears to be leveling off