Isabella Dam
From Wikipedia, the free encyclopedia
Isabella Dam is located at , about halfway down the Kern River, between the towns of Kernville and Lake Isabella in Kern County, California. Isabella dam serves agricultural, hydroelectric, and flood control uses. Lake Isabella is also a popular recreation spot.
[edit] History
In 1948, Congress appropriated funds for a dam at the confluence of the north and south forks of the Kern River to prevent flooding of the city of Bakersfield. The city had suffered extreme flooding in 1867, 1893, and even in 1950, during the construction of the dam. The dam was completed in March of 1953.
The dam is of earthen build, 1695 feet (517 m) long and 98 feet (30 m) tall. The dam is owned and maintained by the U.S. Army Corps of Engineers. The reservoir that it creates is called Lake Isabella. Lake Isabella is considered the halfway point of Kern river, the Upper Kern River flows into Lake Isabella, and the water that flows through Isabella Dam is the Lower Kern River. Isabella Dam actually consists of two dams, the "main dam", and the “auxiliary dam”. Water from Lake Isabella can be used in any of three ways. It is released into the Lower Kern River from the main dam, through the Isabella Partners Hydroelectric Project from the main dam, and into the Borel Hydroelectric Project from the auxiliary dam. Normal release from the main dam is 3,000 cubic feet per second (80 m³/s), maximum historical releases were 7,200 ft³/s (200 m³/s) in 1983, and the Borel Project diverts up to 600 ft³/s (17 m³/s) from the auxiliary dam. Design capacity of the channel through the canyon is over 8000 ft³/s (230 m³/s).
[edit] Leak
As of April 28, 2006, a leak was found in the Isabella Auxiliary Dam. Officials determined that it would be necessary to restrict the maximum reservoir elevation to 20 feet (6 m) below the spillway, or normal "full" pool. The dam's releases through the outlet have been increased, allowing the water to flow at 4,500 ft³/s (130 m³/s). Due to more than average rainfall and snowpack in the mountains, and warmer than average temperatures in the area in May, the Upper Kern has been filling up the lake faster than officials can lower it. The Lower Kern is also running higher than normal, and flowing at up to 20 miles per hour (30 km/h) in some parts. Highway 178, which goes up the canyon between Bakersfield and Lake Isabella, has become unstable, and one lane closed, due to the high water levels[1]. Some flooding has been reported by property owners along the river. Emergency management officials have warned that if Isabella Dam were to fail when the reservoir was full, a large part of Bakersfield would be inundated within 2 to 4 hours. Isabella dam is also located on a fault line thought to be inactive, but now is judged as possibly an active earthquake source, and Federal Engineers believe that an earthquake might cause the dam to fail, depending on the size of the earthquake.
