Dams have been built in this century that impound virtually all major rivers in the United States. The purposes vary and include flood control, navigation, hydropower generation, and storage for irrigation and domestic uses. About 2,500 reservoirs of 5,000 acre-feet or more, store about 480 million acre-feet, about 1/4 of the annual runoff. Storage capacity is dominated by large reservoirs such that the 600 largest store more than 90 percent of the total. Lake Powell, behind Glen Canyon dam, stores water (ca. 27 million acre-feet) in the Upper Basin of the Colorado River for controlled release according to the Colorado River Compact (8.23 million acre-feet per year) and to generate electricity for sale to consumers in the Southwestern [...]
Summary
Dams have been built in this century that impound virtually all major rivers in the United States. The purposes vary and include flood control, navigation, hydropower generation, and storage for irrigation and domestic uses. About 2,500 reservoirs of 5,000 acre-feet or more, store about 480 million acre-feet, about 1/4 of the annual runoff. Storage capacity is dominated by large reservoirs such that the 600 largest store more than 90 percent of the total. Lake Powell, behind Glen Canyon dam, stores water (ca. 27 million acre-feet) in the Upper Basin of the Colorado River for controlled release according to the Colorado River Compact (8.23 million acre-feet per year) and to generate electricity for sale to consumers in the Southwestern United States (about 80 percent of the generating capacity of the Colorado River Storage Project). Phenomena that control the quantity (evaporation, losses to ground water, consumptive uses in the basin, regional drought or El Nino effects, and so forth) and (or) quality (salinity , productivity, sediment-water column exchange, etc.) of Lake Powell waters are not understood. Specific objectives of this project are to initiate investigation of basic processes that mediate water quality in Lake Powell and to couple understanding of Lake Powell to management of water quality of the Colorado River in the Grand Canyon National Park.
