WalnutWhat a house pays

Walnut water and sewer rates

Who supplies water to Walnut houses, what it costs, and how the sewer charge works.

Walnut Valley Water District

Walnut Valley Water District, single-family rates effective January 1, 2026: a monthly base rate by meter size plus three tiers per unit (1 unit = 748 gallons); homes in pumping zones 2 and 3 pay $0.30 or $0.55 more per unit.

Use a monthPrice per unit (CCF, 748 gallons)
Fixed charge$41.98 a month
0 to 6 units$4.02
6 to 27 units$5.08
27 to more$6.75
Source
Walnut Valley Water District imports 100% of its drinking water through Three Valleys Municipal Water District and the Metropolitan Water District: about 60% from MWD's Weymouth plant, 39% from TVMWD's Miramar plant and 1% groundwater.
Hardness
Total hardness averaged 234 ppm in the water from MWD's Weymouth plant and 97 ppm in the water from TVMWD's Miramar plant.
Lead
In tap samples from 30 sites in 2024 the 90th-percentile lead result was 0 ppb and no site was above the action level; the District's 2024 service line inventory found no lead or galvanized service lines requiring replacement.

Suburban Water Systems (San Jose Hills)

Suburban Water Systems, San Jose Hills service area: monthly service charge plus two blocks of quantity rates per 100 cubic feet, plus a 0.70% surcharge that funds the CPUC reimbursement fee.

Use a monthPrice per unit (CCF, 748 gallons)
Fixed charge$17.09 a month
0 to 20 units$5.85
20 to more$6.40
Source
Suburban serves the San Jose Hills service area from its wells in the Main San Gabriel Groundwater Basin; in 2025 local groundwater made up 88 percent of its supply.
Hardness
Total hardness averaged 217.1 ppm (12.7 grains per gallon) in the groundwater and 163 ppm (9.50 grains per gallon) in the treated surface water tested in 2025.
Lead
None of the 51 lead and copper samples collected from residences in 2025 exceeded the action level; the lead 90th-percentile result was ND.

Sewer

County Sanitation District No. 21, which covers all or portions of Walnut, charges $224 per single-family home for 2026-27 and collects it on the property tax roll. The County's Consolidated Sewer Maintenance District, whose service areas include the City of Walnut, charges $78.50 per sewage unit (one single-family dwelling) for July 2026 to June 2027, collected on the tax roll as a sewer service charge.

Ways to pay less

  • Low-income households: Suburban Water bill credit. Suburban Water Systems' Customer Assistance Program in its San Jose Hills area, which includes portions of Walnut, gives qualifying residential customers a credit of $11.14 a month; the income limits follow the CPUC's CARE program. How: Show a CARE-type discount on your electric or gas bill or fill out Suburban's self-verification form; renew every two years.
  • Low-income seniors over 62: Safe, Clean Water parcel tax exemption. Owners over 62 who live in the home and head a low-income household can apply for an exemption from the Safe, Clean Water Program special parcel tax; the FY 2027-28 limit is $106,600 for a 2-person household. How: Submit the claim form to the Safe, Clean Water Program by May 1 each year; call 833-275-7297.
  • Low water use: reduced sanitation district charge. District No. 21 parcels with significantly lower water usage may be eligible for a reduced service charge; dischargers with verified low water usage, particularly seniors and retirees, may qualify. How: Apply to the Sanitation Districts' low water rebate program.

Dates

WhenWhat
May 1, 2027Deadline for low-income seniors to apply for the Safe, Clean Water Program parcel tax exemption for FY 2027-28.

Pay or manage it

Sources

  1. LA County Public Works: Consolidated Sewer Maintenance District annual report
  2. Walnut Valley Water District: single-family residential rates 2026
  3. Walnut Valley Water District: rate schedules and classes
  4. Walnut Valley Water District: district overview
  5. Walnut Valley Water District: 2025 Consumer Confidence Report
  6. Walnut Valley Water District: 2024 cost-of-service rate study
  7. Suburban Water Systems Schedule SJ-1 (San Jose Hills residential)
  8. Suburban Water Systems Schedule UF
  9. Suburban Water Systems Advice Letter 407-W-A
  10. Suburban Water Systems San Jose Hills 2025 water quality report
  11. LA County Public Works: sewer maintenance rates
  12. Metropolitan Water District FY 2026/27 tax rate resolution
  13. LA County Public Works Safe Clean Water tax layer: median Walnut single-family tax
  14. LA County Public Works Safe Clean Water tax layer description
  15. Safe, Clean Water Program: FY 2027-28 low-income senior exemption form
  16. Safe, Clean Water Program: tax appeal procedures and guidelines
  17. Metropolitan Water District FY 2026/27 water standby charge resolution
  18. Suburban Water Systems Schedule CAP-1

Checked October 22, 2026. Every number here comes from the public sources listed, matched by our checker.

Rates change every year; this page shows when it was last checked. Nothing here is legal, tax or insurance advice.