The St. Francis Dam disaster of 1928 convinced the City of Los Angeles to reinforce the Mulholland Dam with tons of earth on the downstream side and to lower the level of the reservoir as a precaution against the possibility of a similar catastrophe. In California history, the failure of the St. Francis dam is second only to the 1906 San Francisco earthquake in terms of loss of life. Around midnight on March 12, 1928, approximately 12.5 billion gallons of water poured down the narrow San Francisquito Canyon, creating a 140-foot-high wall of water that swept away nearly 500 men, women, and children. As the dam's engineer and designer, William Mulholland was personally and professionally devastated, and died a broken man. Ironically, in 1992, a group of geologists headed by J. David Rogers discovered that the cause of the disaster was not in the design of the dam, but rather in the geology of the rock foundation. Sophisticated equipment identified that the east abutment had been anchored into a Paleolithic landslide that could not have been detected at the time of the original construction. As a credit to its engineer, the Mulholland Dam has withstood the test of time.

To provide additional reservoir capacity, a small dam was subsequently built in the northern end of the lake. In 1974, the California State Department of Health Services issued a directive to further improve both water quality and the protection of open water reservoirs. In addition to the normal environmental hazards that threaten open bodies of water, the Upper and Lower Hollywood reservoirs also faced potential contamination by surface runoff from the surrounding communities. One proposal for protecting these waters was to install reservoir covers. In protest of this plan, fifteen community groups formed the Coalition to Preserve Open Reservoirs (CPOR). As a result of the opposition effort, a mediation process took place which led to the current solution of buried water storage and a small filtration plant at the base of the dam.

Soon the City of Los Angeles' Department of Water and Power (DWP) moved toward completion of new underground water storage tanks adjacent to the Upper and Lower Hollywood Reservoirs. To make room for these tanks, more than one million cubic yards of soil had to be excavated. Much of the dirt was placed in fill sites in four canyons near the tanks, and the landform was graded to blend with contours of the existing hillsides. Once the earth moving and grading was completed, fill sites were planted and irrigated. Ground irrigation continued for three or four years, after which the established vegetation was maintained by rainwater alone. Today, the surrounding hillsides are covered by chaparral and coastal sage scrub plant, while fully grown oaks, eucalyptus, pine and wild walnut trees shade much of the path around the lake. Two of the world's largest underground tanks now store treated water, with new pipelines linking the tanks to the distribution system. Because these Toyon tanks provide the drinking water previously supplied directly from the Hollywood Reservoirs, the need to chlorinate the reservoirs has been eliminated. The reservoirs are kept full in case of emergency, and the DWP is able to environmentally manage them to help maintain the natural ecosystem.

The reservoir's proximity to Hollywood has made it a convenient location for film shoots. Most notably, Lake Hollywood can be seen in Roman Polanski's Chinatown (1974) starring Jack Nicholson and Faye Dunaway, and in Universal's disaster epic Earthquake (1974) starring Charlton Heston and a long cast of others. To get to Lake Hollywood from Los Angeles, take 101 Freeway north, exit at Barnham Boulevard and turn right. Turn right onto Lake Hollywood Drive and follow the signs to the reservoir. Because it is a reservoir for drinking water, the lake is not open for swimming or boating and dogs are not allowed on the perimeter path. On clear days, joggers and hikers can enjoy the natural scenic beauty that surrounds the reservoir, including visibility of the Hollywood Sign on Mount Lee and the sculpted skyline of Tinsel Town. Lake Hollywood is home to an abundance of wildlife including deer, coyotes, rabbits, squirrels, turtles, hawks, ducks, California quails, woodpeckers, hummingbirds and numerous blue jays.

My wife and I enjoyed a leisurely walk from the North Gate to the Weidlake Gate and back, approximately two miles. The scent of the magnificent fir trees filled the air, and the birds' songs lulled us into believing that in this peaceful and majestic place we were far away from the hustle and bustle of the nearby metropolis. We took many photographs during our walk, several of which are included in this website. Be advised, however, that due to security issues all photography at the reservoir is now prohibited.