Ever gazed upon a man-made marvel silently serving millions? Stone Canyon Reservoir is such a place.
Nestled in the Santa Monica Mountains this reservoir isn’t just a pretty face. It’s a vital part of Los Angeles’ water system. Stone Canyon Reservoir and its smaller neighbor Upper Stone Canyon Reservoir supply water to nearly 400000 people. Think Pacific Palisades Santa Monica Mountains and West Los Angeles. This essential resource quietly serves a large part of the city.
The history of Stone Canyon Reservoir is rich. Designed and built in 1924 by the Los Angeles Department of Water and Power’s Bureau of Water Works and Supply its original capacity was a massive 8000 acre-feet. William Mulholland a legendary figure in LA water history pioneered the hydraulic sluicing method used in its construction. This innovative technique involved using powerful water jets to move earth.
In the 1950s the dam underwent significant upgrades. The upstream section was rebuilt using roller compacted backfill a modern technique for the time. The downstream portion however remained unchanged. Safety was paramount. Seismic studies conducted in 2002 confirmed the dam’s ability to withstand earthquakes safely operating at its design elevation.
But Stone Canyon Reservoir isn’t just about engineering marvels. It has faced challenges. Being an open surface reservoir it didn’t initially meet water quality standards. Surface runoff caused contamination. This led to the construction of a 20000 square foot membrane filtration plant. This plant cost between $65 and $70 million. It processes 6.5 million gallons of water daily. It serves the 400000 customers. A security fence protects this crucial facility.
Interestingly a change in radon levels near Stone Canyon Reservoir began in 1984. This may be linked to changes in the reservoir’s water level. The reservoir also played a part in popular culture. It served as a location for the classic film Chinatown and featured in novels such as Irving Wallace’s The Fan Club.
Today Stone Canyon Reservoir is mostly decommissioned for regular use. It serves as an emergency water source. A 63-inch diameter pipeline bypasses the reservoir for regular water delivery. The treated water comes directly from the Los Angeles Aqueduct Filtration Plant. Plans are underway to potentially replace the Upper Stone Canyon Reservoir with underground reservoirs and hiking trails. The reservoir remains a testament to LA’s ingenuity its dependence on water and its ongoing efforts to balance infrastructure needs with environmental concerns. Stone Canyon Reservoir a hidden gem a silent worker a story etched in both concrete and history.