Graywater and reuseGuide
Laundry to landscape in Sonoma County
You can send washing machine water to your plants. The state says no permit. Permit Sonoma says a plumbing permit. Call (707) 565-1900 before you dig.
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The permit question
State plumbing code: a clothes washer system that follows the code's conditions is exempt from a construction permit.
Permit Sonoma: its graywater page lists a clothes washer system as needing no septic permit but needing a building (plumbing) permit.
These two pages do not match. Permit Sonoma covers unincorporated Sonoma County only. It does not regulate graywater in the cities. Ask your own building department which rule applies to your address.
Rules the county lists for a clothes washer system
- One household clothes washer, in a one or two family home.
- A diverter valve that can send the water to the sewer or septic tank.
- Use the diverter when the soil is saturated.
- Water comes only from the washer or laundry tub.
- All the water stays on your property.
- It meets the site and waterway setbacks in the county table.
- Water goes below the surface, under at least 2 inches of soil, rock, mulch or other approved cover.
- Do not use it on root crops or on the parts of food crops that touch the soil.
Good habits
- Pick a detergent made for graywater. Skip bleach, or divert to the sewer when you use it.
- Rotate which basin gets the water.
- Do not spray it. The county brochure says no spray or overhead irrigation.
Detergent and rotation tips are editorial advice. The diverter-for-bleach point also appears in a Hilltromper profile of a local installer.
Graywater means water from showers, tubs, bathroom sinks and washing machines. It does not include toilets, kitchen sinks or dishwashers.
Sources
- Permit Sonoma, Graywater Systems
- Permit Sonoma, Clothes Washer System Requirements
- Sonoma Water, Graywater
- Greywater Action, California rules for no-permit systems
- Sonoma County Energy Independence Program graywater brochure, via City of Sebastopol
Checked 2026-10-11. Rules and programs change. If something here is out of date, the source above wins. Spot an error? See our corrections policy.
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