The 2-mile-long, 97-foot-high Hansen Dam was built in 1940 to control floodwaters and silt that flow down the Big and Little Tujunga Canyon stream channels during heavy rainfalls. The lake was formed when “burrow pits” or holes that were excavated to provide gravel to build the dam filled up with water.

What happened to Hansen Dam?

Millions and millions of tons of sand, gravel and silt that for 50 years washed into the Hansen Dam reservoir and choked the lake to death, killing what was the East San Fernando Valley's most popular recreation area.

When was the Hansen Dam built?

Hansen Dam and Reservoir was built by the U.S. Army Corps of Engineers, Los Angeles District and completed in September 1940. It is located in the City of Los Angeles at the confluence of the Big and Little Tujunga Washes along the northeastern edge of the San Fernando Valley.