Los Angeles water by area

LADWP publishes water quality for five parts of Los Angeles, and each part draws on different plants and wells. Plant averages in 2025 ran from 103 mg/L at the Los Angeles Aqueduct plant to 236 mg/L at Metropolitan Water District's Diemer plant.

Which one serves my home?

Find your neighborhood in the lists below, which come from LADWP's 2026 water quality report.

San Fernando Valley

LADWP lists these communities: Arleta, Canoga Park, Chatsworth, Encino, Granada Hills, Hollywood Hills, Lake View Terrace, Mission Hills, North Hills, North Hollywood, Northridge, Olive View, Pacoima, Panorama City, Porter Ranch, Reseda, Sherman Oaks, Studio City, Sun Valley, Sunland, Sylmar, Tarzana, Toluca Lake, Tujunga, Valley Village, Van Nuys, Warner Center, West Hills, Winnetka, Woodland Hills. Source: LADWP 2026 Drinking Water Quality Report.

• Average 103 mg/L, range 96-117 mg/L for total hardness, Los Angeles Aqueduct plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.
• Average 115 mg/L, range 78-151 mg/L for total hardness, northern wells, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.
• Average 140 mg/L, range 137-142 mg/L for total hardness, MWD Jensen plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.

Published figures here run from 103 to 140 mg/L, about 6.0 to 8.2 grains per gallon by our conversion. That reads as moderately hard to hard on the USGS scale.

• LADWP lists its water sources here as Los Angeles Aqueduct, local groundwater, and MWD State Water Project. Test results for this area are under the LA Aqueduct Filtration Plant, Northern Combined Wells and MWD Jensen Plant columns. Source: LADWP 2026 Drinking Water Quality Report.

Western Los Angeles

LADWP lists these communities: Bel Air Estates, Beverly Glen, Brentwood, Castellamare, Century City, Cheviot Hills, Culver City, Mar Vista, Pacific Palisades, Palisades Highlands, Palms, Playa del Rey, Sawtelle, Venice, West Los Angeles, Westchester, Westwood. Source: LADWP 2026 Drinking Water Quality Report.

• Average 103 mg/L, range 96-117 mg/L for total hardness, Los Angeles Aqueduct plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.

The published figure here is 103 mg/L, about 6.0 grains per gallon by our conversion. That reads as moderately hard on the USGS scale.

• LADWP lists its water sources here as Los Angeles Aqueduct and MWD State Water Project. Test results for this area are under the LA Aqueduct Filtration Plant column. Source: LADWP 2026 Drinking Water Quality Report.
• LADWP says the source of drinking water in Culver City may change with operating needs and supply. Source: LADWP 2026 Drinking Water Quality Report.
• The report lists the State Water Project as a source here, but points only to the Aqueduct plant column for test results. Source: LADWP 2026 Drinking Water Quality Report.

Central Los Angeles

LADWP lists these communities: Baldwin Hills, Chinatown, Country Club Park, Crenshaw, Griffith Park, Hancock Park, Hollywood, Hyde Park, Koreatown, L.A. City Strip, Little Tokyo, Los Feliz, Mid City, Mt. Olympus, Park La Brea, Rancho Park, Silverlake, Watts, West Hollywood, Westlake. Source: LADWP 2026 Drinking Water Quality Report.

• Average 103 mg/L, range 96-117 mg/L for total hardness, Los Angeles Aqueduct plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.
• Average 116 mg/L, range 83-159 mg/L for total hardness, southern wells, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.

Published figures here run from 103 to 116 mg/L, about 6.0 to 6.8 grains per gallon by our conversion. That reads as moderately hard on the USGS scale.

• LADWP lists its water sources here as Los Angeles Aqueduct, MWD State Water Project, and local groundwater. Test results for this area are under the LA Aqueduct Filtration Plant and Southern Combined Wells columns. Source: LADWP 2026 Drinking Water Quality Report.
• LADWP says the source of drinking water in L.A. City Strip and West Hollywood may change with operating needs and supply. Source: LADWP 2026 Drinking Water Quality Report.

Eastern Los Angeles

LADWP lists these communities: Atwater Village, Boyle Heights, Cypress Park, Eagle Rock, Echo Park, El Sereno, Glassell Park, Highland Park, Lincoln Heights, Montecito Heights, Monterey Hills, Mt. Washington. Source: LADWP 2026 Drinking Water Quality Report.

• Average 234 mg/L, range 189-280 mg/L for total hardness, MWD Weymouth plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.
• Average 236 mg/L, range 191-280 mg/L for total hardness, MWD Diemer plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.
• Average 140 mg/L, range 137-142 mg/L for total hardness, MWD Jensen plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.

Published figures here run from 140 to 236 mg/L, about 8.2 to 13.8 grains per gallon by our conversion. That reads as hard to very hard on the USGS scale.

• LADWP lists its water sources here as MWD State Water Project and Colorado River Aqueduct. Test results for this area are under the MWD Weymouth, MWD Diemer and MWD Jensen columns. Source: LADWP 2026 Drinking Water Quality Report.

Harbor

LADWP lists these communities: East San Pedro (Terminal Island), Harbor City, Harbor Gateway, L.A. City Strip, San Pedro, Wilmington. Source: LADWP 2026 Drinking Water Quality Report.

• Average 234 mg/L, range 189-280 mg/L for total hardness, MWD Weymouth plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.
• Average 236 mg/L, range 191-280 mg/L for total hardness, MWD Diemer plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.
• Average 140 mg/L, range 137-142 mg/L for total hardness, MWD Jensen plant, calendar year 2025. Source: Drinking Water Quality Report 2025 (LADWP), Table III.

Published figures here run from 140 to 236 mg/L, about 8.2 to 13.8 grains per gallon by our conversion. That reads as hard to very hard on the USGS scale.

• LADWP lists its water sources here as MWD State Water Project and Colorado River Aqueduct. Test results for this area are under the MWD Weymouth, MWD Diemer and MWD Jensen columns. Source: LADWP 2026 Drinking Water Quality Report.
• LADWP says the source of drinking water in Harbor Gateway and L.A. City Strip may change with operating needs and supply. Source: LADWP 2026 Drinking Water Quality Report.

Across the 5 Los Angeles areas above, the figures run 103 to 236 mg/L, which spans USGS classes from moderately hard to very hard. Each is a plant, well or area figure, not a reading at one address. (USGS hardness classes)

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Sources last checked October 27, 2026. Los Angeles Water Systems is not a water utility.