Placer County, CA Landscaping Rules: Rainwater Harvesting (2026)
Key Facts
- Governing section
- County Code § 15.75.090
- Legal status
- encouraged/recommended, not a mandate
- Mandatory element
- friable soil for water retention
- Suggested storm sizing
- 1-inch or 85th-percentile, 24-hr event
- Applies to
- landscapes ≥500 sq ft new, ≥2,500 sq ft rehab
- Tahoe Basin
- exempt; TRPA governs instead
Summary
Placer County's landscape ordinance treats rainwater harvesting as encouraged, not required. Section 15.75.090 recommends capture and infiltration capacity sized to the one-inch or 85th-percentile 24-hour storm and lists rain gardens, cisterns and catchment systems as optional design elements. Friable soil for water retention is the one mandatory piece.
1. Stormwater management practices minimize runoff and increase infiltration which recharges groundwater and improves water quality. Implementing stormwater best management practices into the landscape and grading design plans to minimize runoff and to increase on-site rainwater retention and infiltration are encouraged. 2. Project applicants shall refer to the local agency or Regional Water Quality Control Board for information on any applicable stormwater technical requirements. 3. All planted landscape areas are required to have friable soil to maximize water retention and infiltration. 4. It is strongly recommended that landscape areas be designed for capture and infiltration capacity that is sufficient to prevent runoff from impervious surfaces... from either: (1) the one-inch, 24 hour rain event; or (2) the 85th percentile, 24 hour rain event... 5. ...e. Incorporate rain gardens, cisterns, and other rain harvesting or catchment systems.
Full Breakdown
010(2)(e)). Within that scope, subsection 1 states that implementing stormwater best management practices to minimize runoff and increase on-site rainwater retention and infiltration is 'encouraged,' not mandated. Subsection 2 directs applicants to the local agency or the Regional Water Quality Control Board for any applicable stormwater technical requirements, rather than setting a county numeric standard itself. 020(2)(d)(iv)(1). Subsection 4 recommends, but does not mandate, sizing capture and infiltration capacity to prevent runoff from impervious roof and paved surfaces from either a one-inch, 24-hour rain event or the 85th-percentile, 24-hour rain event.
Subsection 5 lists recommended, non-mandatory design elements including grading impervious surfaces to drain to vegetation, minimizing impervious paving, using pervious or porous surfaces, directing roof runoff to planting beds, and incorporating rain gardens, cisterns, and other rain harvesting or catchment systems, as well as infiltration beds, swales, basins, and drywells.
Violations & Fines
Because § 15.75.090's rainwater retention and harvesting provisions are phrased as 'encouraged' and 'recommended,' failing to install a cistern, rain garden, or catchment system is not itself a code violation. The only enforceable piece tied to this section is the friable-soil requirement in subsection 3, which is checked during the same landscape plan review and final inspection process under § 15.75.150, with enforcement running through Chapter 17, Article 17.62, Code Compliance and Enforcement.
Frequently Asked Questions
Is rainwater harvesting mandatory in unincorporated Placer County?
What storm size should a rainwater system in Placer County be designed for?
Does this section apply to properties in the Tahoe Basin?
Sources & Official References
Other rules in Placer County
California rules heatmap·Compare Placer County to another location·View the California landscaping rules overview
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