Tacoma, WA Landscaping Rules: Rainwater Harvesting (2026)
Key Facts
- Small tanks
- 600 gal or less, each under 4' wide
- Lot-line clearance
- minimum 3 feet required
- Yard coverage cap
- 10% of yard area
- Front-yard tanks
- must be screened from view
Summary
Tacoma's zoning code lets rain barrels, tanks and cisterns encroach into a required yard setback, with size and clearance limits that scale up for larger catchment tanks.
Rainfall catchment systems, which may include rain barrels, tanks or cisterns as well as associated piping, may extend into a required yard setback according to the following:
Rainfall catchment tanks no greater than 600 gallons shall be allowed to encroach into a required setback if each tank is less than 4' wide (as measured perpendicular from the side of the house or principal structure), a minimum 3' clearance from the lot line is maintained, and provided that the cumulative coverage of the tanks does not exceed 10% of each yard area.
Rainfall catchment tanks larger than 600 gallons may be permitted in a required setback provided that they do not exceed 10% coverage of any required yard, and they are not located closer than 3' from a side or rear lot line, or 15' from the front lot line. If located in the front, the rainfall catchment tank must be screened.
Rainfall catchment tanks may not impede requirements for lighting, open space, minimum usable yardamenity space, required walkways, and fire protection or egress.
The rainfall catchment system shall not obstruct any escape window and shall not create a
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4946110; v22 updated 2026-07-28).
Full Breakdown
Tacoma's zoning code carves out a specific exception to its yard-setback rules for rainwater catchment. Tanks of 600 gallons or less may sit inside a required setback if each tank is under 4 feet wide, kept at least 3 feet from the lot line, and the tanks together cover no more than 10% of the yard. Larger tanks are also allowed in a setback under the same 10% coverage cap, but must stay 3 feet from a side or rear lot line, 15 feet from the front lot line, and be screened if placed in the front yard. Catchment equipment can't block an escape window or overload a retaining wall.
Violations & Fines
Placing an oversized or unscreened catchment tank inside a required setback, crowding the lot line, or exceeding the 10% yard-coverage cap is a setback-encroachment violation subject to Tacoma code enforcement.
Frequently Asked Questions
Can I put a rain barrel in my required side-yard setback in Tacoma?
Are large cisterns allowed in a required front yard?
Sources & Official References
Other rules in Tacoma
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