Environmental Impact Research Program. Survey of Habitat-Related Channel Featuresand Structures in Tailwaters

摘要

Man-made dams usually result in modification of water quality (and aquatichabitats) in the resulting impoundments and in the tailwaters immediately downstream. These tailwaters have as great a sports fishing potential and other recreational potential as the main impoundment. Various methods designed to promote desired habitats have been employed by Government agencies having projects altering natural streamflow. Streambed modifications are relatively inexpensive ways of increasing habitat by increasing the surface area available to aquatic biota, usually resulting in small disruption to the stream channel flow. Tailwater management may include the use of weirs as 'passive' aerators to maintain streamflow, temperature, and dissolved gases at prescribed levels. Both U.S. Federal agencies and foreign governments have employed weirs, modified power generation operation, and forced oxygen below surface impoundments to enhance water quality and for other purposes.