San Diego County · San Diego–Chula Vista–Carlsbad metro
Plumbing help in San Diego, CA
Very Hard WaterNewer Homes
San Diego imports most of its water, and that water is hard. Scale is behind a large share of local plumbing calls, from water heaters to tankless units to fixtures. About half the city's housing also predates 1980, so aging pipe comes up often in older neighborhoods.
- Median home built
- 1980
- Built before 1980
- 50%
- Owner-occupied
- 47%
- Water hardness
- Very hard
- ≈ 13 grains/gal
- Winter
- Hard freezes are rare
- Plumbing code
- Local
The plumbing calls that come up most in San Diego
- Water Heater Repair
At roughly 13 grains per gallon, sediment and scale shorten tank life and cause rumbling and lost capacity.
- Tankless Water Heaters
Tankless heat exchangers scale quickly in water this hard, so regular descaling matters.
- Water Softener Installation
Many households soften to protect water heaters, fixtures and appliances, subject to local rules on brine discharge.
San Diego's very hard water and your plumbing
San Diego historically imports 80% to 90% of its water from the Colorado River and Northern California. In 2024, average hardness at the city's treatment plants was about 12.6 to 13.4 grains per gallon (Alvarado, Miramar and Otay). [1]
Emergency plumbing in San Diego
Call (833) 878-1592Shut off your main water supply if it's safe to do so. The emergencies below are listed most likely first for San Diego homes, based on local conditions.
Polybutylene-era homes in San Diego
The median home in San Diego was built in 1980, and 50% of homes predate 1980. Homes from that era were typically built with copper or CPVC supply, plastic drains, and in some homes gray polybutylene supply pipe.
- Galvanized steel supply (1900–1960)
- Copper supply (1950–2000)
- Polybutylene (some homes) (1978–1996)
- PEX / CPVC (1995–today)
Plumbing services for San Diego homes
San Diego plumbing questions
How hard is San Diego tap water?
Hard. The city's 2024 report lists averages of about 12.6 to 13.4 grains per gallon at its three treatment plants.
How often should I descale a tankless water heater in San Diego?
Follow the manufacturer's schedule, and treat it as a minimum with water around 13 grains per gallon. Many owners descale yearly, and flow problems or error codes are a sign it's overdue. See tankless water heaters.
Why is San Diego water hard?
Most of it is imported from the Colorado River and Northern California, and the river water carries dissolved minerals from its long route.
Sources (2)
- U.S. Census Bureau, ACS 2024 1-year (B25035) · checked 2026-10-01
- City of San Diego Public Utilities, 2024 Annual Drinking Water Quality Report · checked 2026-10-01