There are two ways to fill up Canyon Lake: rain and water purchased from the Metropolitan Water District (MWD).
The primary source of water is rainfall that goes directly into the lake and from storm water that flows into the lake from the San Jacinto River Watershed.
The secondary source is from water purchased by Elsinore Valley Municipal Water District (EVMWD) from MWD, which flows down the San Jacinto River into Canyon Lake from turnouts 11 miles upstream. It can take weeks to reach Canyon Lake. MWD water is imported from Northern California or the Colorado River.
The lake is a drinking water reservoir and plays an important role during periods of peak customer water demand. EVMWD’s filtration plant serves customers in the Elsinore Valley and Canyon Lake residents.
EVMWD owns all water rights in Canyon Lake. The Canyon Lake POA leases the recreational surface rights through an agreement with EVMWD.
Per the lease agreement between EVMWD and the Canyon Lake POA, EVMWD can take water from Canyon Lake down to 1,372 feet above sea level. About four to five feet of water is lost to evaporation each year.
If the lake level falls below the minimum level of 1,372 feet and EVMWD does not purchase water to bring the level back up to the minimum level, the POA can withhold its quarterly payment to EVMWD, per the lease agreement.
In 2016-2017, EVMWD closed the Canyon Lake Water Treatment Plant for repairs. The plant went back on in late 2017 and EVMWD processed water again after a year of having to buy water from MWD. Imported water is more expensive than water processed from Canyon Lake, so the decision to purchase water is not taken lightly.
Canyon Lake holds approximately 12,000 acre-feet of water. The spillway elevation is 1,381.76 feet above sea level. If rainfall causes the lake level to exceed that amount, water gushes over the spillway into the San Jacinto River channel and flows to Lake Elsinore. Heavy rainfall in December 2016 and January 2019 caused the water to spill over.
The construction of the dam began in 1927 and was completed two years later.
While the dam’s original concrete structure remains in place, the configuration was altered in 1996 when EVMWD spent more than $9 million to improve its safety by widening and refurbishing the dam to withstand a 100-year flood event.