Spillway
under construction, April 1963. The earthen embankment is seen at top
right.
Thomas E. Petermann Collection (S-2005-89-116)
The lake is divided into two parts. The conservation pool, at 1,200 feet above sea level, holds water for power generation and municipal and industrial use. At its normal water level, about 28,000 acres of land are covered by the lake. The ten feet above the conservation pool is reserved for the flood pool. Often empty, it can hold up to 300,000 acre-feet of floodwater.
When the flood pool fills and the Corps of Engineers determines that floodwater needs to be released from the reservoir, seven steel, curved, tainter gates at the top of the dam’s spillway are raised electrically. Water flows down the arched spillway away from the base of the dam and into the concrete stilling basin where large baffles (blocks) disperse the energy of the water being released downstream.
The spillway gates have been opened several times over the years to regulate floodwaters. The sight of millions of gallons of water rushing down the spillway is a spectacular event and always draws a crowd.
Amount
of water in one acre-foot: 325,850 gallons |
|