Overlooking the hills on the north face of the Santa Monica Mountains lies the Encino Reservoir. This controlled lake was created by damming Encino Creek. It is near the Encino neighborhood in the San Fernando Valley. The Encino Reservoir stands 327 m above sea level. Completed in 1924, the Encino Reservoir is owned by the Los Angeles Department of Water and Power or LADWP.
Let’s step back to the early 20th century. William Mulholland designed the Encino Reservoir in 1921. It was intended to supply drinking water to the San Fernando Valley population. The original design lacked a control gate. A single pipe with a valve maintained pressure in the water distribution system. It acted as an “equalizer” of water pressure.
The dam’s construction used a roll-filled method. Earth was layered, sprinkled with water, and compacted. After its initial filling, seepage occurred. Between 1949 and 1950, a downstream filter and buttress were added to fix the problem. Then from 1960 to 1962, the upstream part of the original dam was removed. A new 51.2 m roll-filled dam was constructed.
Before 1971, the Encino Reservoir held significant importance. It, along with the Lower Stone Canyon and Lower Van Norman reservoirs, stored 70 percent of the LADWP’s water. Most of Los Angeles’ water came from snowmelt in the Sierra Nevada. It drained into the Owens Valley and traveled via the Los Angeles Aqueduct system.
The Encino Reservoir faced challenges. The 1971 San Fernando earthquake caused no damage. But it prompted a review of the reservoir’s role during emergencies. In 1972, seismoscopes were installed at the crest and west abutment. The 1994 Northridge earthquake epicenter was 7.2 km north of the Encino Reservoir. The dam suffered minor cracking.
Today, the Encino Reservoir no longer provides drinking water. It is kept open for other purposes. It stores water to maintain supply through the Los Angeles Aqueduct. It regulates water for irrigation in the summer. The Encino Reservoir played a crucial role in firefighting during the 2025 Palisades Fire. Helicopters drew water from the reservoir to combat the flames.
The Encino Reservoir’s management and risk are closely monitored. The reservoir is inspected yearly. Its condition is satisfactory. But its hazard potential is high. This means failure could cause loss of life. The State of California manages dam safety through the Division of Safety of Dams. They consider the risk of downstream hazard from a dam breach as extremely high.
The Encino Reservoir offers recreational assets. Visitors can enjoy walking trails and nature areas. The California scrub oak woodland provides a glimpse into local wildlife. The surface area is 0.69 km2 and the drainage basin is 3.63 km2. The average annual rainfall is 48 cm, but evaporation averages 120 cm per year.
The story of the Encino Reservoir reflects Los Angeles’ constant need for water. It highlights the ingenuity and challenges of managing this precious resource. As you stand here, consider the history beneath your feet. The Encino Reservoir remains a vital part of Los Angeles’ water infrastructure. It shows a commitment to balancing safety, supply, and recreation.