Ada County, ID Water Use Rules: Recycled Water Rules (2026)
Key Facts
- Applies to
- Planned communities in unincorporated Ada County
- Governing section
- Ada County Code § 8-12-4
- Wastewater rule
- Centralized treatment and reuse service required
- Nonresidential irrigation
- Reclaimed water required when available
- Residential lots
- Automated irrigation sprinklers mandatory
- Adopted
- Ord. 1002, effective 10-28-2025
Summary
Planned community developments in unincorporated Ada County must provide centralized wastewater treatment with reuse service and use reclaimed water for nonresidential irrigation when available, under Ada County Code Section 8-12-4. Residential lots must carry automated sprinkler systems to cut waste. The mandate applies only to Planned Community (PC) zoned projects, not ordinary subdivisions.
8-12-2: APPLICABILITY: This Chapter applies to the development of planned communities within unincorporated Ada County. ... 8-12-4: URBAN PUBLIC SERVICE LEVEL STANDARDS: ... A. Minimum Urban Public Service Level Standards: ... 4. All nonresidential lots shall have pressurized irrigation systems, using reclaimed water when available and permissible under all applicable federal, state, and local rules and laws. ... 1. A centralized wastewater treatment and reuse service, or connection to an existing system shall be provided to every property within the planned community by a municipality, a private sewer company, or a sewer district established pursuant to Idaho Code Section 42-3201 et seq. ... 3. If treated wastewater will be used for irrigation, then the irrigated area and the amount of treated wastewater used for irrigation shall be identified in the planned community implementation plan.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-15: Code current through: Ord. 1018, passed 3-24-2026).
Full Breakdown
" The separate Wastewater treatment category requires a centralized wastewater treatment and reuse service, or connection to an existing one, run by a municipality, private sewer company, or sewer district under the same Idaho Code chapter. If treated wastewater will be used for irrigation, the developer's planned community implementation plan must identify the irrigated area and the volume of reclaimed water applied. The Board of County Commissioners may waive or alter the centralized wastewater treatment requirement lot by lot where topography or other site conditions make it infeasible.
The rule, adopted by Ordinance 1002 effective October 28, 2025, is aimed at large master-planned developments (the model being Hidden Springs) rather than standard platted subdivisions.
Violations & Fines
Because Chapter 12 sits within Title 8 (Zoning), noncompliance with the reuse and centralized wastewater standards is enforced as a Zoning Ordinance violation under Section 8-8-2: it is a misdemeanor punishable under Idaho Code Section 18-113, with each day the deficiency continues after notice treated as a separate offense. The Director of Development Services can also bring a violation of implementation plan conditions to a public hearing under Section 8-8-3, where the deciding body may modify, condition, or reverse the planned community's approval until the reuse and treatment standards are met.
Frequently Asked Questions
Does Ada County require recycled water in new subdivisions?
What wastewater standard applies to an Ada County planned community?
Can Ada County waive the centralized wastewater treatment requirement?
Do residential lots in an Ada County planned community need special irrigation?
Sources & Official References
Other rules in Ada County
Compare Ada County to another location·View the Idaho water use rules overview
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