Mulholland Dam and Hollywood Reservoir
The Mulholland Dam is a concrete-arched gravity dam built as a large reservoir in the Hollywood Hills. The dam was built between August 1923 and December 1924 under the supervision of William Mulholland, chief engineer for the City of Los Angeles Bureau of Water Works and Supply. The reservoir formed behind the dam was called the Hollywood Reservoir (later Lake Hollywood) and would hold up to 2.5 billion gallons of water from the Owens River Aqueduct System (LA Aqueduct) and from the groundwater of the San Fernando Valley.
|(1924)* - View shows the construction of the Mulholland Dam and Hollywood Reservoir.|
|(1925)* - The Mulholland Dam is a dam located in the Hollywood Hills of Los Angeles. It was named after the designer William Mulholland, who was also responsible for the design of the aqueducts and reservoirs for Los Angeles.|
From the LADWP Historic Archive
Tuesday, the 17th of March, 1925, in addition to being St. Patrick’s Day, was also a red-letter day in the annals of the Department of Public Service. To those who were fortunate enough to be the recipients of an invitation to be present at the dedication of that monumental structure in Weid Canyon, the Mulholland Dam, the day will be forever memorable as signalizing the erection of another symbolic milestone to mark the progress of this incomparable city of Los Angeles.
Mulholland Dam, enshrining forever in imperishable stone the name and the fame of its designer and builder, Chief Engineer William Mulholland, not only ranks as one of the great engineering accomplishments of its kind in the United States, but it also stands unique in that it is located squarely in the midst of a thickly populated metropolitan area.
Because of this fact and of its standing at an elevation overlooking and dominating the entire Hollywood section and the downtown Los Angeles district, two major considerations overshadowed everything else in its design and construction – the factors of safety and beauty.
With the inflexible determination that no Johnstown Disaster should ever overwhelm the City of the Angels, the form of the Dam was, for greater safety, thrust forward upstream against the pressure to come, arching in a vast curve like a colossal bow in order to transmit the approaching future strains as a lateral stress to the wide and ample shoulders of the unyielding walls of the canyon which it spans. So great is the resultant strength engendered by this construction and so vast the margin of safety occasioned thereby that no pressure that can in the course of nature be brought to bear against it can ever overstrain or overcome the resistant qualities of Mulholland Dam. Indeed, it has been reliably calculated that if Lake Hollywood, which it impounds, were filled with molten lead instead of water, the Dam would still stand. This becomes all the more impressive when it is recalled that, bulk for bulk, lead is 11.4 times heavier than water, the weight of a cubic foot of lead being 710 pounds as against 62 ½ pounds for a like volume of water.
And then because not only of its commanding position, dominating the city and the cynosure of all eyes for miles around in its enframing background of circling hills, but also because “a thing of beauty is a job forever,” it was determined to make Mulholland Dam sightly and beautiful, as well as solidly and safely utilitarian. How well, this determination was carried out and the vision realized all who have seen the superb structure can abundantly testify.
Constructed of solid concrete, 200 feet in span and 160 feet in thickness at its base, bedded upon the everlasting rock, the white walls of Mulholland Dam tower upward 200 feet into the air between the precipitous hillsides of Weid Canyon to a thickness of 16 feet and a span of 975 feet at its crest, culminating in a roadway flanked on either side by four foot balustraded sidewalks, thus proving a twenty-four-foot viaduct over the entire structure.
Beginning construction in August 1923, the dam proper was completed on December 24, 1924, just in time to figure as the most elaborate, graceful and costly Christmas token for the municipal stocking, ever tendered to the city of Los Angeles. in all a total of 172,800 cubic feet of concrete were poured, at a cost to the city of $1,250,000, in round figures, being at the rate of slightly more than $6 per cubic yard, as against $10 to $12 per cubic yard, the average cost of similar concrete structures elsewhere.
Filled to it full height, Mulholland Dam is capable of impounding 2,500,000,000 gallons of water, a supply sufficient to cover 8,000 acres of land to a depth of one foot. Primarily, the purpose of this vast flood is to furnish gravity pressure for Hollywood and the northwest and the foothill section of the city, all of which will be supplied by direct connection. As one link in a chain of fifteen storage and distribution units, Mulholland Dam and Lake Hollywood will from now on constitute one of the most vital portions of the entire water supply system of Los Angeles.
While the Aqueduct is also available, the present source of supply is from a battery of sixteen wells, drilled and drilling, tapping the enormous accumulations of water seeping form the excess of surface irrigation into the deep and almost bottomless gravels of the San Fernando Valley. Lake Hollywood is now being filled through nine miles of 36-inch pipe from eight completed wells, the level standing at 120 feet on the day of the dedication, or considerably less than one-half the rated capacity of the reservoir.^
|(1925)* - Hollywood Reservoir and Mulholland Dam are shown with a crowd walking across the dam during the dedication ceremony. An American flag can be seen draped over one of the towers.|
|(1925)* - Hollywood Reservoir and Mulholland Dam during dedication ceremonies. William Mulholland is shown standing in the car. To the rear are several riders on horseback.|
|(1925)* - Hollywood Reservoir and Mulholland Dam during dedication ceremonies, showing dignitaries in a car with Los Angeles City seal on the door. To the left are flags and the edge of a dedicatory plaque can be seen.|
|(1925)* - William Mulholland standing in an open automobile in front of American flags at the dedication of the Mulholland Dam and Hollywood Reservoir. Click HERE to see the William Mulholland Biography.|
|(1925)* - Caption reads: Graceful arches and landscaping make Hollywood Dam an object of beauty as well as of service in providing a valuable reserve water supply for Hollywood and other districts of Los Angeles.|
|(1925)* - Mulholland Dam and Hollywood Reservoir seen here with the clouds reflecting off the water.|
|(1928)* - View of Mulholland Dam and Hollywood Reservoir (also known as Lake Hollywood) both designed and built by engineer William Mulholland, for which the Dam is named after.|
|(1929)*^ - Front view of Mulholland dam in the Hollywood Hills, the most beautiful of a score of storage basins in Los Angeles' water system. The Hollywoodland sign can be seen in the background.|
|(ca. 1929)*^ - An overview of the hills with a Mulholland Dam and Hollywood Reservoir off on the right, partially hidden by the steamshovel setting at the top of the near hill.|
|(ca. 1929)*^ - Panoramic view of Hollywood and West Los Angeles, as seen from Mt. Lee. Lake Hollywood (Hollywood Reservoir) and “Hollywoodland” is in the foreground.|
|(ca. 1930)*^ - Profile view of the Mulholland Dam. A man can be seen looking over the rail.|
|(ca. 1935)*^ - Hollywood Reservoir and Mulholland Dam after landscaping. The front of the dam wall has been filled in with dirt for additonal reinforcement and planted with trees and bushes.|
|(April 1933)* - Hollywood Reservoir Pumping Plant - Dwarfed by a comparison with Hollywood Dam, which towers immediately above it, a new pumping and chlorinating plant is nearing completion in the hills of Hollywood.
The new concrete structure, modern in design, will replace the existing corrugated iron Vinecrest pumping and chlorinating plant. Regular service to the Hollywoodland district and emergency service to the Las Palmas system, will be provided by the new plant.^
|(ca. 1930s)* - Interior of the Hollywood Pumping Plant.|
|(1935)* - Mulholland Dam seen rising above the pumping plant.|
|(1941)* - Landscaping completed at the Mulholland Dam and Hollywood Reservoir.|
The Mulholland Dam was later reinforced with tons of earth on the downstream side as a precaution after the similar St. Francis Dam burst in 1928. Later studies confirmed that the St. Francis disaster was not caused by a faulty design.
Click HERE to see more in St. Francis Dam Disaster.
|(n.d.)* - Partial view of the Hollywood Dam on the Hollywood Reservoir, overlooking the Bryn Mawr residential subdivision immediately adjacent to the Dam. A backward "Bryn Mawr" sign can be seen on the left portion of the hillside, and behind that facing south, the sprawling city is visible as far as the eye can see.|
|(n.d.)*^ - View of Hollywood Reservoir with Hollywoodland sign clearly visible on the right side.
|(ca. 1938)*^ - This panoramic view taken from behind the Hollywoodland sign captures the structure of the letters as well as Lake Hollywood on the right.|
|(1967)* - View of Upper Hollywood Reservoir.|
|(1967)* - Upper Hollywood Reservoir showing water flowing into intake.|
|(ca. 1960s)*^ - Aerial view of Hollywood and its surrounding areas. Cars may be seen travelling the Hollywood Freeway. Traffic going north is towards the Valley, going south is towards Los Angeles. The Hollywood Reservoir can be seen is in the hills above Hollywood.|
Due to more stringent safety and water quality regulations, both the dam and reservoir are no longer being utilized as they were when they were originally built. Two of the world’s largest underground tanks now store treated water, with new pipelines linking the tanks to the distribution system.
Click HERE to see more in Early Los Angeles Water Reservoirs.
References and Credits