In 1924 the Hollywood Hills became home to the Mulholland Dam, engineered by William Mulholland, who was primarily responsible for designing and supervising the construction of the system of aqueducts and reservoirs that provide Los Angeles with most of it’s drinking water. Lake Hollywood, the resulting reservoir, was engineered to hold more than 2.5 billion gallons of water from the Owens River Aqueduct system (a.k.a. the LA Aqueduct) and the groundwater of the San Fernando Valley. A small dam was subsequently built in the northern part of the lake to provide additional reservoir capacity.
As a reservoir for drinking water, the lake is not open for swimming or boating and dogs are not allowed on the perimeter path. In 1974, the California State Department of Health Services directed the Department to further improve water quality and the protection of open distribution reservoirs.
In addition to normal environmental exposure faced by open bodies of water, the Upper and Lower Hollywood reservoirs could be contaminated by surface runoff. The initial plans, in 1988, proposed to install reservoir covers. To protest these plans, 15 community groups (including the HKCC) formed the Coalition to Preserve Open Reservoirs (CPOR).
Finally in 1990, a mediation process let to the current solution of buried water storage and a small filtration plant at the base of the dam. The City of Los Angeles, Department of Water and Power (DWP), is now moving toward completion of new water storage facilities next to the Upper and Lower Hollywood Reservoirs. Two of the world’s largest underground tanks will store treated water with new pipelines linking the tanks to the LA distribution system.