Lake Hollywood is a man made reservoir built in 1924 in the Hollywood Hills East of the 101. Mulholland Dam (pictured above) was engineered by William Mulholland who is famous for designing and building the Los Angeles aqueducts. The Lake holds 2.5 billion gallons of water.
After the St. Francis Dam burst accident of1928, the Mulholland Dam was reinforced with earth and trees.
This picture below was taken in 1933 after the dam was reinforced
Because Lake Hollywood is used for drinking water, the lake is closed to swimming/boating and dogs are not allowed on the 3.2 mile walking path that surrounds the lake.
Ground water run off is a big issue for Lake Hollywood because the runoff contaminates the reservoir. In 1990 two Toyon water storage tanks were installed below the lake with a water treatment plant. The underground tanks are some of the world’s largest. The reservoir remains full in case of emergency. The Lake is no longer chlorinated. This is great for homeowners in the area because it protects the ecosystem and keeps the lake odor-free.