Los Angeles River

The los angeles river is located in southern California. It is only 52 miles long but is very steep: It drops 795 feet in elevation from the headwaters in the San Fernando Valley to its end in Long Beach. The majority of its sourcewaters flow from the San Gabriel Mountains, which are east of the San Fernando Valley, and from the Santa Susanna Mountains to the north.

The Los Angeles River flows through the San Fernando Valley, the Glendale Narrows, and the city of Los Angeles, and empties into the Pacific Ocean. Major tributaries to the river in the San Fernando Valley are the Pacoima Wash, Tujunga Wash, Burbank Western Channel, and Verdugo Wash; the main tributaries to the river in Glendale Narrows are the Arroyo Seco, the Rio Hondo, and Compton Creek.

Most of the Los Angeles River is bedded by concrete. To prevent flooding and make room for construction, 47.9 miles of the river were channelized from 1914–70. The Glendale Narrows to Long Beach section of the river still has a natural bed, and is surrounded by forest, grassland, savannah, and shrubland, but flora and fauna still exist in the channelized section. Sixty species of native plants have been identified in the river, including fish, reptiles, amphibians, and some mammals.

Despite its concrete bed, the river continues to flood. The Los Angeles River has other problems as well. Due to the high urbanization of the Los Angeles area, much of the Los Angeles River watershed is covered with residential, commercial, and industrial areas, including major refineries and petroleum product storage facilities.

This situation increases the demand for water and also increases the contamination of most local water sources. Although the Los Angeles River boasts water that is cleaner than water in most urban rivers around the world, it is still polluted from residential, industrial, and other urban activities. Contamination is worse during rainy seasons and pollution is more concentrated in some areas than in others. Erosion problems and fires also affect this watershed. These problems in the Los Angeles basin have sparked efforts to decrease water contamination, protect the wildlife habitat, enhance recreational areas, manage storm water quality, and prevent flooding and fires.

The Los Angeles city government has developed several programs to aid in these efforts, such as the Los Angeles River Master Plan, adopted in 1996, which focuses on flood protection and sustainable development, and the Revitalization Master Plan, adopted in 2005, which seeks to restore the river and create a wildlife corridor from the mountains to the sea.

One important aspect of the Revitalization Master Plan is the participation of environmental groups, such as Friends of the Los Angeles River (FoLAR) and Unpave L.A., thus permitting public involvement and participation in the real processes of decision making.

To prevent flooding and make room for construction, 47.9 miles of the Los Angeles River were bedded with concrete.