Lake Mathews
Lake Mathews is a 5 MW hydroelectric power plant in Riverside County, California, operated by Metropolitan Water District of S CA. EIA-860M lists 1 generating unit here, inside CAISO. Its unit entered service in 1980.
As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m
- Nameplate capacity
- 4.9 MW
- 4.9 MW net summer
- Generating units
- 1
- In service
- 1980
- EIA plant ID
- 6644
Where it is
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- County
- Riverside County, California
- Coordinates
- 33.8553, -117.4537
- Balancing authority
- CISO
- Sector
- Electric Utility
Units, technology and status
- Operator of record
- Metropolitan Water District of S CA
- Primary energy source
- Hydro
- Technologies
- Conventional Hydroelectric
- Status
- Operating
Every plant Metropolitan Water District of S CA reports to EIA →
Lake Mathews: FAQ
- Where is Lake Mathews?
- In Riverside County, California (CA). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.
- How big is Lake Mathews?
- 5 MW of nameplate capacity across 1 unit, as of the EIA-860M release for 2026-07.
- Who owns Lake Mathews?
- EIA-860M names Metropolitan Water District of S CA as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.
- Is this the same as Lake Mathews LLC?
- Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Metropolitan Water District of S CA here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Lake Mathews LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
- Is Lake Mathews still running?
- EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.