Calero Reservoir, also called Calero Lake, is a

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

San Jose, California San Jose, officially San José (; ; ), is a major city in the U.S. state of California that is the cultural, financial, and political center of Silicon Valley and largest city in Northern California by both population and area. With a 2020 popul ...

, located in the Calero neighborhood of

Almaden Valley , other_name= , native_name= es, Almadén , nickname= , settlement_type= Neighborhood of San Jose , total_type= , motto= , image_skyline = , flag_size= , image_sea= , seal_size= , image_shield= , shield_size= , image_blank_emblem= , ...

South San Jose South San Jose is the southern region of San Jose, California. The name "South Side" refers to an area bounded roughly by Hillsdale Avenue and Capitol Expressway to the North, Camden Avenue to the West, Highway 101 and Hellyer Avenue on the east ...

. It is the site of Calero County Park, which also includes a large area covering the lake and hundreds of acres of hills around it.

History

The reservoir was formed by the Calero Dam, built in 1935 across

Arroyo Calero Arroyo often refers to: * Arroyo (creek), an intermittently dry creek Arroyo may also refer to: People * Arroyo (surname) Places United States ;California * Arroyo Burro Beach, a public beach park in Santa Barbara County, California * Arroyo ...

, which is also known as Calero Creek.

Watershed and course

Calero Dam is an earthen dam high and long containing of material. Its crest is above sea level. The reservoir receives flows from the southwest via Cherry Canyon which has its origin at Fern Peak in the southeastern part of the

Santa Cruz Mountains The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central and Northern California, United States. They form a ridge down the San Francisco Peninsula, south of San Francisco. They separate the Pacific Ocean from ...

. It also receives minor inputs from the southeast via the ephemeral flows down Pine Tree Canyon Calero Reservoir is the fourth largest reservoir owned by the

Santa Clara Valley Water District The Santa Clara Valley Water District (also known as Valley Water) provides stream stewardship, wholesale water supply and flood protection for Santa Clara County, California, in the southern San Francisco Bay Area. The district encompasses all of ...

. After capturing winter runoff from the nearby foothills and from water transferred, via a canal, from nearby

Almaden Reservoir Almaden Reservoir is an artificial lake in the hills south of San Jose, California in the United States. It borders on the Almaden Quicksilver County Park, which provides limited fishing ("catch-and-release"), picnicking, hiking, and horseback r ...

, reservoir water recharges groundwater basins and is also provided directly to water treatment plants, via the Almaden Valley Pipeline, to be treated and distributed to county residents. Calero Reservoir also can receive flows from Anderson Reservoir and

San Luis Reservoir The San Luis Reservoir is an artificial lake on San Luis Creek in the eastern slopes of the Diablo Range of Merced County, California, approximately west of Los Banos on State Route 152, which crosses Pacheco Pass and runs along its north ...

, via the recently restored Cross Valley and Calero pipelines which stretch , starting from the Coyote Pump Plant in

Morgan Hill Morgan Hill is a city in Santa Clara County, California, at the southern tip of Silicon Valley, in the San Francisco Bay Area. Morgan Hill is an affluent residential community, the seat of several high-tech companies, and a dining, entertainmen ...

, extending through parts of unincorporated Santa Clara County, and ending at the Calero Reservoir in South San Jose. Because alluvium deposits were found beneath the dam in a 2012 independent engineering study, and these could liquify in an earthquake, reservoir levels are currently maintained 19 feet below the spillway with retrofit construction of the dam scheduled for 2021. This restriction limits Calero Reservoir to 45% of capacity or about 4,414 acre-feet. When the Calero Dam retrofit is completed, the capacity of Calero Reservoir could be restored to 9,738 acre-feet and increase the outlet capacity from 50 cfs to up to 100 cfs. Water from Calero Reservoir is carried downstream by Arroyo Calero, a tributary to Alamitos Creek, which is in turn tributary to the Guadalupe River and thence to south

San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water from a ...

Ecology

The

California Office of Environmental Health Hazard Assessment The Office of Environmental Health Hazard Assessment, commonly referred to as OEHHA (pronounced oh-EEE-ha), is a specialized department within the cabinet-level California Environmental Protection Agency ( CalEPA) with responsibility for evaluatin ...

released a "Do Not Eat" warning regarding eating any fish caught from this reservoir based on the elevated mercury level. The primary fish caught in Calero Reservoir are non-native, including

largemouth bass The largemouth bass (''Micropterus salmoides'') is a carnivorous freshwater gamefish in the Centrarchidae ( sunfish) family, a species of black bass native to the eastern and central United States, southeastern Canada and northern Mexico, but ...

(''Micropterus salmoides''), Eurasian

common carp The Eurasian carp or European carp (''Cyprinus carpio''), widely known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Arkive The ...

(''Cyprinus carpio''), and

black crappie The black crappie (''Pomoxis nigromaculatus'') is a freshwater fish found in North America, one of the two types of crappies. It is very similar to the white crappie in size, shape, and habits, except that it is darker, with a pattern of black sp ...

(''Pomoxis nigromaculatus'').

Recreation

A county park surrounds the reservoir and provides limited fishing ("

catch-and-release Catch and release is a practice within recreational fishing where after capture, often a fast measurement and weighing of the fish is performed, followed by posed photography as proof of the catch, and then the fish are unhooked and returned ...

"), picnicking, hiking, and horseback riding activities. Although swimming is prohibited, boating, water-skiing and jet-skiing are permitted in the reservoir.

References

External links