A laundry to landscape graywater system sends the rinse and wash water from your clothes washer out to the garden instead of down the sewer. In California it is a kind of graywater system that can often go in without a construction permit, as long as it meets a list of conditions in the California Plumbing Code.
This guide covers what the code's no-permit path requires, the extra design rules that Bay Area water agencies attach to their rebates, and how to check whether your house and yard are a good fit. It reflects official pages read in November 2026. Rules and rebate amounts change, so confirm with your own city and water agency before you buy parts.
What a laundry-to-landscape system is
The washer's drain hose feeds a three-way diverter valve. One side of the valve sends water back to the building sewer, as it does today. The other side sends it through a pipe to mulch basins around trees and shrubs. The washer's own pump pushes the water, and the rest of the system works by gravity.
Valley Water's rebate rules describe it this way: the system must be gravity-fed, with no filters, tanks or pumps other than the washer's own pump, and it can't connect to spray or conventional irrigation. EBMUD's rebate lists the parts that make it work: a brass three-way diverter, an air admittance or anti-siphon valve, and a PVC conveyance line.
This is different from the landscape permit rules for larger planting projects, which our guide to MWELO landscape permits and lawn rebates covers.
When the plumbing code says no construction permit is needed
Graywater systems are covered in Chapter 15 of the California Plumbing Code. EBMUD's summary of the code, which doesn't name the edition it quotes, points to section 1502.1.1, which lets a clothes washer system go in without a construction permit if it meets 13 conditions. Here is our plain-English paraphrase of EBMUD's list, not the code's own wording:
Notice, if your agency requires it. If the city requires it, you notify the building or planning department of the system's location and installation.
A labeled switch. You must be able to send the water to the irrigation field or to the building sewer. The control must be clearly labeled and readily accessible.
No potable water connection and no pump. The work can't affect other building, plumbing, electrical or mechanical components, including structural features, exits, fire protection features, sanitation, potable water supply piping or accessibility. The washer's own pump isn't counted as part of the system.
It stays on your lot. The graywater must be contained on the site where it's generated.
It goes to an irrigation or disposal field. The water must be directed to and contained within that field.
No ponding or runoff. The code treats either one as a nuisance.
Covered outlets. Water may be released above ground only if at least 2 inches of mulch, rock or soil, or a solid shield, covers the release point. Other methods that give equivalent separation are also acceptable.
Limited contact. The system must be designed to minimize contact with people and pets.
No diaper loads. Water from washing diapers or similarly soiled or infectious garments must go to the sewer.
No hazardous chemicals. That rules out water from cleaning car parts, washing greasy or oily rags, or home photo lab and similar hobby waste.
Other rules still apply. Being exempt from a construction permit doesn't allow a system that violates other parts of the code or local laws.
An owner's manual. The owner gets an operation and maintenance manual, and it stays with the building for the life of the system, including when the house changes hands.
A trap at the standpipe. If the washer drains through a standpipe, that discharge must be properly trapped.
The 2025 California Building Standards Code, which includes the plumbing code, took effect January 1, 2026, according to the California Building Standards Commission. Agencies don't all cite the same chapter: SFPUC's rebate terms cite Chapter 16 of the plumbing code, while Valley Water and EBMUD cite Chapter 15. Ask your building department which edition and section it applies.
Condition 3 is the one to think about on an older house. If getting a pipe from the washer to the yard would mean changing structural features or other building, plumbing, electrical or mechanical work, the project no longer fits the no-permit path as EBMUD summarizes it. That's a question for your building department and, if you're hiring help, a licensed contractor.
Is your house and yard a good fit?
Valley Water's rebate page lists signs that a property is likely to qualify. They make a practical checklist for any Bay Area house:
The clothes washer is accessible, near an exterior wall, or above a crawl space.
The first graywater outlet is 50 feet or less from the washer, or a bit farther if the run is downhill.
The landscape is level with or downhill from the washer. SFPUC's rules similarly ask for a working washer at or above landscape grade and a yard that is flat or slopes down from it.
You have plants that suit the water. Valley Water names decorative trees, fruit trees, shrubs, groups of smaller plants or establishing drought-tolerant plants, and says trees, shrubs and vines are appropriate choices.
If you are planning plantings around the system, our post on mid-century modern landscaping covers water-wise plants and hardscape that suit the house.
Design rules that come with a rebate
Water agencies can attach their own conditions to a rebate. Valley Water's requirements, as of November 2026, go beyond the code summary above. Distribution points must be at least:
100 feet from wells, waterways or other water sources;
50 feet from any septic tank or leach field;
18 inches from the property line, more if the neighboring lot is downhill;
2 feet from buildings, per its graywater system requirements list.
Another section of the same page gives a different distance from building foundations, so confirm the figure with Valley Water before you lay out the basins.
Valley Water also requires seasonally high groundwater at least five feet below the ground surface, and it checks this itself. The diverter valve and its vent must sit at least 6 inches above the washer's flood rim and be labeled. Exposed graywater pipe must carry the label "Caution: Nonpotable graywater. Do not drink." on every 5 feet. Mulch basins are required, and the area with mulch basins must be sized to prevent runoff and pooling; Valley Water gives you the required square footage before or with its Notice to Proceed. It also asks owners to call 811 before digging and to keep an operating and maintenance manual, with a diagram, at the building.
Bay Area rebates, as of November 2026
Valley Water (Santa Clara County)
Valley Water offers a graywater laundry-to-landscape rebate to homeowners in Santa Clara County with a qualifying property. The base rebate is $200. Residential customers of the City of Milpitas, City of Morgan Hill, City of Palo Alto Utilities, City of Santa Clara Utilities and City of San Jose Muni Utilities may be eligible for $400. The application must be approved before you begin any work. After a post-installation inspection, Valley Water mails payment within 4 to 6 weeks. Its page says current funding lasts until June 30, 2027 or until it runs out. Palo Alto's October 2025 utility bill insert lists the same $400 rebate and refers residents to Valley Water.
EBMUD (parts of Alameda and Contra Costa counties)
EBMUD offers up to $100 toward the parts: a brass three-way diverter, an air admittance or anti-siphon valve, and a PVC conveyance line. The rebate covers the item price only, not tax, labor or shipping. Residential properties of up to 4 units qualify, with an active potable water account, and EBMUD asks applicants to watch a tutorial video. You can buy the parts first and apply within 90 days of purchase, or apply first, wait for approval, and then have 9 months to buy and install.
SFPUC (San Francisco)
SFPUC's rebate is up to $100 for three parts: Schedule 40 PVC pipe (up to $25), a three-way diverter valve (up to $50) and an air admittance valve (up to $25), and no more than you paid. The system must be at a single-family or two-unit property in San Francisco. SFPUC's page says a simple system that doesn't alter the plumbing and follows its 12 guidelines needs no permit at a one- or two-unit building; any other graywater system needs a permit from the San Francisco Department of Building Inspection.
Before you start: a short checklist
Ask your building department whether it wants notice of a laundry-to-landscape system and which plumbing code edition it applies.
If you want a rebate, read the rules first. Valley Water requires approval before any work.
Sketch the mulch basins around trees, shrubs or vines, downhill or level from the washer.
Write the operation and maintenance manual and keep it with the house.
This is general information as of November 2026, not legal or plumbing advice. Codes, local rules and rebates change, so confirm with your city's building department, your water agency and a licensed contractor.
Frequently asked questions
Do I need a permit for laundry to landscape in California?
Often not, if the system meets the conditions in section 1502.1.1 of the California Plumbing Code as EBMUD summarizes them. Those include no pump other than the washer's, no potable water connection, and no changes to other building systems. The first condition covers notice where the city requires it, so check with your building department.
Can I connect graywater to my drip or sprinkler system?
Not for a Valley Water rebate. Its rules say the system can't connect to spray or conventional irrigation and must be gravity-fed, with no filters, tanks or pumps other than the washer's own pump.
What happens to the system when I sell the house?
The code conditions, as EBMUD summarizes them, say the operation and maintenance manual stays with the building for the life of the system, including a change of ownership. Sellers should leave it for the buyer. Buyers should ask for it and check that the diverter valve is labeled.
Related reading
Flat Roof Drainage on Mid-Century Homes: Fascia, Gutters and Grading
Tree Removal Permit in Palo Alto and Nearby Cities Before a Remodel
More guides on this topic: Owning & Renovating a Mid-Century Modern Home
Planning garden or water projects on a mid-century home you own or want to buy? Call or text the Boyenga Team at Compass at (408) 373-1660 or (650) 383-8606, or contact the Boyenga Team to talk it through.
