The Sam Rayburn Dam and Reservoir was authorized and constructed for the purpose of flood control, hydroelectric power generation, and to conserve and supply water for municipal, industrial, agricultural, and recreational uses. Management and operational decisions must be made in accordance with these three main missions, which in part explains why the lake levels fluctuate so frequently. When substantial rains create the potential for flooding, incoming waters from the Angelina River watershed are retained within Sam Rayburn Reservoir's flood pool, and the lake level rises. Once the threat of downstream flooding is reduced, flood waters are released into the Angelina/Neches Rivers, which maintains higher flows (but below flood stage) in the rivers until the levels in Sam Rayburn are reduced.
Also, the waters in Sam Rayburn can be released through the two 26,000 KW hydroelectric generators to produce an annual average of more than 118 million kilowatts for users in Southeast Texas and Southwest Louisiana.
Sam Rayburn Reservoir is touted as one of the premier largemouth bass fisheries in the South, and is home to over 300 fishing tournaments each year, including ESPN/BASS Masters, BASS Champs, Wal Mart BFL, FLW Outdoors, Angler's Quest, BASS Champs, Bass-n-Bucks, McDonald's Big Bass Splash and numerous others.
The Sam Rayburn Dam is 19,430 feet long, and contains 114,500 surface acres of water when at the Conservation pool elevation of 164.40' . At the flood control pool (elevation 173') the reservoir hold 1,140,500 acre feet of water (1 acre of water, 1 foot deep) which is spread over 142,700 surface acres. Sam Rayburn also features the first accordion weir emergency spillway constructed by the US Army Corps of Engineers. Construction on the dam began in 1956, deliberate impoundment of water began in March, 1965, and the conservation pool level (164.4') was reached in 1966. Additional information on the construction and history of the Sam Rayburn Dam and reservoir can be found at History