Pierce County, WA Landscaping Rules: Rainwater Harvesting (2026)
Key Facts
- Minimum system size
- 1,500 gallons per structure for base credit
- Base credit tier
- 10-year retention facility rate
- Top credit tier
- Matches 100-year storm retention facility
- Program sunset
- Pre-2017 Credit Program ends Jan. 1, 2027
- Max credit cap
- $12,500 per parcel, 2021 onward
- Plumbing permit fee
- $0.00 under Table 17C.10-1-D
- Delinquent charge interest
- 12% per year under PCC 11.02.080
Summary
Pierce County credits roof rainwater collection systems against the county's stormwater utility service charge under PCC 11.02.050.B.7. A system that captures at least 1,500 gallons per structure for later nonpotable use earns the same discount as a 10-year retention facility, and larger systems that can be drained within 24 hours qualify for higher credit tiers, but the whole program sunsets January 1, 2027.
7. Roof rainwater collection systems, which retain stormwater on site for later nonpotable use, will be credited as retention facilities. Systems that are properly sized for their intended use and have a capacity of at least 1,500 gallons per structure will be assigned the same credit as a 10-year Retention Facility. Larger systems capable of retaining the 25-, 50- or 100-year storms will be credited at the higher level as long as the stored water can be utilized within a 24-hour period. Refer to Volume III of the Pierce County Stormwater Management and Site Development Manual for roof rainwater collection systems.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 2026-515, and legislation passed through May 26, 2026).
Full Breakdown
A. B, which the code reviser's note confirms sunsets on January 1, 2027. 7: a system sized to hold at least 1,500 gallons per structure for later nonpotable use is credited at the same rate as a 10-year retention facility, while systems built to retain the 25-, 50- or 100-year storm earn the matching higher retention-facility credit tier, as long as the stored water can be used within 24 hours. Design guidance sits in Volume III of the Pierce County Stormwater Management and Site Development Manual. 5. 10. 010.
Violations & Fines
There is no separate fine written into PCC 11.02.050 for a misapplied rainwater harvesting credit, but the underlying service charge does not disappear: if a credit is denied or the balance goes unpaid, PCC 11.02.080 lets Pierce County record a lien enforced the same way as a sewerage lien, and delinquent service charges accrue 12 percent annual interest, computed monthly, until the parcel is paid current.
Frequently Asked Questions
Does Pierce County charge a fee to install a rainwater harvesting system?
How much stormwater credit can a rainwater harvesting system earn?
Is the rainwater harvesting stormwater credit permanent?
Sources & Official References
Other rules in Pierce County
Compare Pierce County to another location·View the Washington landscaping rules overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.