The Hansen Dam is a flood protection dam that was built on the 20.9 km long Tujunga Wash, a tributary of the Los Angeles River. The Hansen Dam is located about 1.6 km downstream from the meeting point of the Big and Little Tujunga Creek Washes on the northeastern edge of the San Fernando Valley, in the suburb of Lake View Terrace in the city of Los Angeles, California. This 30 m high dam was built by the US Army Corps of Engineers to slow and redistribute water flow to prevent devastating flooding in the San Fernando Valley and the city of Los Angeles.
About the dam
A view of the Hansen Dam.
The Hansen Dam is a huge horseshoe-shaped earth wall that was built on the Tujunga Wash creek and is 3.2 km long, 9.14 m wide and 30 m maximum height above the creek bed. The dam consists of a 5.26 km² reservoir, which is often called Hansensee. The reservoir has a storage capacity of 91,400,000 cubic meters. The dam extends in an east-west direction at right angles to the creek and the dam itself follows a gentle curve to connect the couplings of the dam to a ledge located near the heart of the dam. At its eastern end, the dam is bordered by a series of small hills, while the dam ends in a gently sloping hill at the western end. Near the middle of the dam is the overflow structure with a ridge height of 323 m. In addition, there is a concrete-lined rectangular overflow gutter, which encloses the drainage channel in its center and is mainly intended to discharge the overflow runoff beyond the earth dam.
Hansen Dam Recreation Area
The Hansen Dam Leisure Center in Los Angeles. Editorial Credit: USA STOCK IMAGES / Shutterstock.com
The US Army Corps of Engineers has only reserved a small area of the Hansen Dam and the reservoir for maintenance purposes. The remaining area was made available to the city of Los Angeles for recreational purposes. The local Hansen Dam Recreation Center and Park day care facilities are managed by the Department of Recreation and Parks of the City of Los Angeles. On the northwest side of the Hansen Dam Recreation Area is the Hansen Dam Aquatic Center, a 0.16 km² water recreation facility that includes a small recreational lake and a much smaller swimming lake. In addition, the facility has 20 changing rooms, 25 showers, 50 public toilets and many picnic areas. There are many equestrian and hiking trails in the park that connect it to the Angeles National Forest. However, much of the area remains undeveloped in order to preserve and maintain the natural habitats and rich biodiversity of the area.
The 1938 Los Angeles Flood is considered one of the most devastating floods in Los Angeles history, killing 115 people and causing $ 78 million in property damage. The ongoing flooding and damage in the eastern part of the San Fernando Valley made the authorities aware of the need for a stronger network of flood protection projects in the region. For the next several years, the US Army Corps of Engineers worked with the Los Angeles County Flood Control District on a project to channel the rivers, creeks, and large washes of the city of Los Angeles. The project is named after the horse breeders Homer and Marie Hansen, who built a ranch near the project area in the 19th century. In 1939, the Corps acquired the Hansen Ranch to help build the dam. In September 1940, the dam, overflow and drainage works were completed at an initial cost of over $ 11 million. In 1946, the recreational opportunities of the Hansen Dam were considered by the authorities, as the basin served as a popular tourist destination from the beginning with more than 75,000 visitors annually. In 1952, the City of Los Angeles began development of the basin with the creation of Holiday Lake. Holiday Lake originally had an area of 0.53 km², but was reduced to 0.32 km² in 1975 due to sediment build-up. In 1982 the leisure activities such as swimming, boating and fishing in the holiday lake were given up and in 1983 the lake only had an area of 0.12 km². The holiday lake was filled up by 1991 and was therefore completely abandoned.
Diptarka Ghosh October 28, 2021 in Orte
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