Larkspur water and sewer rates

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

Marin Water

Marin Water rates effective July 1, 2026; most customers are billed every other month. A single-family home with a 5/8-inch meter pays a $55.61 service charge and a $36.47 capital maintenance fee per bill, plus $10.86 per unit for the first 15 units in the billing period, $14.19 for units 16 to 25, $22.92 for 26 to 80 and $35.07 above 80. Every unit also carries a $0.66 watershed management fee. One unit is 748 gallons

Use a month	Price per unit (CCF, 748 gallons)
Fixed charge	$46.04 a month
0 to 7.5 units	$11.52
7.5 to 12.5 units	$14.85
12.5 to 40 units	$23.58
40 to more	$35.73

Source: About 75% of Marin Water's supply is rain on its protected Mt. Tamalpais watershed and the hills of west Marin; it adds Russian River water from the Sonoma County Water Agency.
Lead: Marin Water says lead was not detected above the regulatory action level in its water supply.
PFAS: Marin Water says the source of its reservoir water is not susceptible to PFAS contamination.

Sewer

Ross Valley Sanitary District collects its sewer service charge on the yearly Marin County property tax bill. Its Ordinance 102 sets the maximum annual sewer service charge for a single-family home in the Larkspur Rate Zone at $1,918 from July 1, 2026. Larkspur properties north of Corte Madera Creek (such as Greenbrae and Drake's Landing) and in Riviera Circle pay the Ross Valley Rate instead (a $1,340 maximum from July 1, 2026).

Ways to pay less

Low-income households: 25% off the sewer service charge. Ross Valley Sanitary District's assistance program takes 25% off the sewer service charge on the property tax bill for an owner-occupied single-family home whose household income is under the low-income limit. The 2026/27 application was due June 30, 2026, and approval lasts one year, so you apply again each year. How: File Ross Valley Sanitary District's Sewer Service Charge Assistance Program application with proof of income (a tax return or a PG&E bill showing CARE).
Low-income households: Marin Water charge waiver. Single-family customers with household income at or below 80% of the HUD low-income level for Marin County, who have the account in their name and water-efficient fixtures, can have the bimonthly service charge, capital maintenance fee and watershed management fee waived. Water use is still billed at the usual rates. How: Download the application from Marin Water's discount programs page and return it to Marin Water's Customer Service Department with proof of income.

Dates

When	What
Jun 30	Applications due for Ross Valley Sanitary District's sewer charge assistance (a new one each year) and the Marin Wildfire low-income senior exemption.

Pay or manage it

Sources

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.