The Los Angeles River is a strange amalgam of concrete and nature, winding approximately 51 miles from the San Fernando Valley to the ocean in Long Beach. It has been prone to flooding for centuries, with eight major floods occurring in the Valley since 1861.The most devastating of these was the 1938 flood, which caused extensive damage and destruction across the region. This event was the impetus for the formation of the county's Flood Control District, which initiated the first flood control projects, such as river canals and reservoirs. The 1938 flood was caused by a pair of ocean storms that spread inland across the Los Angeles Basin in February and March 1938, resulting in abnormal rainfall across much of the coast of Southern California.
The rains lasted 3 days and the Great Tujunga Wash dam broke. Seventy-seven of its expansion basins were destroyed. The phones and electricity were turned off. Lot and the Olive Avenue bridge were razed to the ground.
It took 30 days to clear the debris from the storm. Around 108,000 acres (44,000 ha) were flooded in Los Angeles County, and the most affected area was the San Fernando Valley, where many communities had been built during the economic boom of the 1920s in low-lying areas that were once used for agriculture. Five people died when the 250-foot Lankershim Boulevard bridge collapsed on the Los Angeles River in Universal City. The floods that occurred between 1914 and 1934 were some of the most economically devastating floods in Los Angeles history.
Although the 1938 flood caused the greatest damage of all floods in Los Angeles history, rainfall and river peaks were not even close to those of the Great Flood of 1862, which was the largest known flood by total volume of water. In Los Angeles alone, more than 1,500 homes were left uninhabitable and aid agencies sheltered 3,700 residents. Frank Gehry is working to revitalize a three-mile stretch of the Los Angeles River concrete canal and turn it into a picturesque park. Originally an alluvial river that ran freely across an alluvial plain, this project seeks to restore some of its natural beauty while also providing a safe way for flood waters to reach their destination.
The 1938 flood was a major impetus for channeling the Los Angeles River in particular, accelerating the flow of flood water to the sea. This event also led to increased efforts to control flooding in Los Angeles County through projects such as river canals and reservoirs. Although it is impossible to prevent flooding entirely, these efforts have helped reduce its impact on local communities and businesses over time.