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Mulholland Dam and Hollywood Reservoir

Hollywood Reservoir
Capacity 2,500,000,000 Gals.
Maximum Depth of Water 183 Ft.

Mulholland Dam
Work started August 1923
Dam completed December 1924
172,000 cu. yds. of concrete
Elevation of roadway 749.5

Wm. Mulholland
Chief Engineer

H.L. Jacques
Construction Engineer

Mulholland Dam was the last great work of William Mulholland, the chief architect and engineer of Los Angeles' water system. By the time this dam was completed, at the end of 1924, construction had started on a larger dam of nearly identical design on San Francisquito Creek, in northern Los Angeles County. That structure, St. Francis Dam, was completed in 1926. It collapsed on March 12, 1928, unleashing a flood that killed about 450 people and scoured the countryside all the way to the Pacific Ocean. That disaster ended Mulholland's career. It also led to a reassessment of his namesake dam, which impounded billions of gallons of water in a steep canyon on the very edge of the city of Los Angeles. In the early 1930s, Los Angeles Department of Water and Power reinforced the downstream face of the dam with 300,000 cubic yards of earth, at the same time adding plantings of shrubs and trees. The net effect was to yes, strengthen the dam, but also to make it virtually disappear. It remains a great spot for a walk, though -- there's a three-mile-long (mostly) paved path around the reservoir -- and a real curiosity for the water and infrastructure geek in your life. 

A couple of good writeups:
Mulholland Dam and Hollywood Reservoir, Water and Power Associates (complete with fantastic historical photos)
The Mulholland Dam's Vanishing Act (KCET). 

Submitted by: @danbrekke

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