Los Angeles River
Originally named Nuestra Senora de los Angeles de la Porciuncula in 1769 by Father Juan Crespi of the Spanish Portola expedition, the 51-mile Los Angeles River stretches from its headwaters in the upper San Fernando Valley to its mouth in San Pedro Bay, draining the Santa Susana and San Gabriel Mountains and San Fernando Valley. Prior to 1769, the river provided food, water and shelter to the indigenous Tongva people. During the 1700s, the Los Angeles River ran through a fertile river where California Lilacs, Arrow Willows and California Sycamore trees flourished, egrets, mule deer and raccoons roamed and Steelhead trout swam through clear waters. It was also critical in the founding of the city of Los Angeles in 1781, providing water for a rural community where farmers grew corn, wheat, grapes and orchard fruits.
The early 20th century saw an explosion of housing and business development along the rivers’ natural floodplain as tens of thousands from all over the globe moved to Los Angeles to enjoy its temperate weather. Several catastrophic and deadly floods in the early 1900s would forever change the Los Angeles River, as the Army Corps of Engineers made the decision in the 1930s to concrete 400 miles of the river and its tributaries to mitigate future flooding concerns. The channelization of this 834 square-mile watershed unintentionally created a system where urban runoff and pollution from city streets flowed untreated to San Pedro Bay. Because of this, in the mid to late 1900s, many Angelenos never even realized that Los Angeles had a river, viewing its graffiti-laden walls as blight instead of a natural resource.
Together with community organizations and environmental groups, the City of Los Angeles is working to improve water quality in Southern California. Projects throughout the watershed are improving water quality by reducing the amount of pollution flowing into rivers and creeks that drain into the Los Angeles River.