1 / 23

Reservoirs

Reservoirs. Various Uses. Irrigation, electricity generation, flood control, water supply (urban), improved navigation, fish culture, recreation, combination. Most are small. Built for irrigation by damming rivers in low rainfall (low runoff) areas. Reservoirs vs. Natural Lakes.

uri
Download Presentation

Reservoirs

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Reservoirs

  2. Various Uses • Irrigation, electricity generation, flood control, water supply (urban), improved navigation, fish culture, recreation, combination

  3. Most are small • Built for irrigation by damming rivers in low rainfall (low runoff) areas

  4. Reservoirs vs. Natural Lakes • Much in common • Reservoirs usually have larger drainage basins for their size • Reservoirs usually younger • Reservoirs have greatest depth at dam

  5. Large Reservoirs • 3 types • Mainstream run-of-river • Tributary storage • Mainstream storage

  6. Mainstream run-of-river • Used to generate electricity • Rapid flushing • Little or no stratification • No drawdown • Water release from deep outlet • Most river-like

  7. Columbia RiverGrand Coulee Dam

  8. Tributary storage reservoirs • Built on smaller rivers • Used for irrigation, flood control • Slower flushing • Stratified if deep enough • Periodic drawdowns • Surface outlet • Most like natural lakes in area

  9. Acton Lake, Ohio

  10. Mainstream storage reservoirs • Intermediate in “position” between other types • More lotic during periods of high runoff • More lentic during other times

  11. Mainstream storage reservoirs • Lie in well-defined river valleys • Exhibit pronounced longitudinal zonation

  12. Mainstream storage reservoirs

  13. Flushing rates • If flushing rate is greater than the doubling time of planktonic organisms, washout will occur • Poor development environment for plankton

  14. Impacts on river • Lentic system built into a lotic environment • Interferes with migration

  15. Prickett Dam, Michigan

  16. Impacts on river • Modified timing, volume of discharge • Interferes with life histories of biota • Trapping materials behind dams • Creates erosional habitats downstream

  17. Prickett Dam, Michigan

  18. Impacts on river • Largest threat – large-scale water diversion for agriculture, especially in dryland areas • Reduced or zero discharge, loss of downstream wetlands, biota

  19. Drawdowns • Necessary for dam maintenance • Increase flood capacity • Remove accumulated sediments

  20. Drawdowns • Exposure, desiccation of littoral zone • Pronounced effects on biota

  21. Benefits and Costs • Benefits • Development • Agriculture • Fisheries • Costs • Flooding • Modified river reaches • Above, below

More Related