Norwalk, CA Landscaping Rules: Rainwater Harvesting (2026)
Key Facts
- Governing section
- Muni. Code § 17.03.020(Q)
- Design storm
- 1-inch or 85th-percentile, 24-hour rain event
- Incentive
- onsite rainwater capture can simplify permit under §17.03.020(C)(3)
- Cross-reference
- stormwater rules in Muni. Code Ch. 18.04
- Techniques listed
- rain gardens, cisterns, infiltration beds, drywells
Summary
Norwalk's Water Efficient Landscape Ordinance makes on-site rainwater capture part of every covered landscape design: grading and infiltration must handle a one-inch or 85th-percentile storm, and projects meeting their entire water need from stored rainwater or graywater on small lots qualify for a simplified permit path.
Q. Stormwater Management and Rainwater Retention. 1. Landscape and grading design plans shall be developed in accordance with the applicable provisions of the stormwater and urban runoff control provisions set forth in Chapter 18.04 of Title 18 of the municipal code. 2. All planted landscape areas are required to have friable soil to maximize water retention and infiltration. 3. Landscape areas shall be designed for capture and infiltration capacity that is sufficient to prevent runoff from impervious surfaces from either: a. The one inch, 24 hour rain event; or b. The 85th percentile, 24 hour rain event. 4. As feasible, storm water projects should incorporate the following to improve on-site stormwater and dry weather runoff capture and use: ... e. Incorporate rain gardens, cisterns, and other rain harvesting or catchment systems; f. Incorporate infiltration beds, swales, basins, and drywells to capture storm water and dry weather runoff and increase percolation into the soil;
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4609620; v5 updated 2025-12-16).
Full Breakdown
020(Q). 04, keep planted soil friable enough to maximize infiltration, and size on-site capture and infiltration capacity to absorb runoff from either a one-inch, 24-hour storm or the 85th-percentile, 24-hour storm. 4 then lists specific rainwater harvesting techniques the City wants incorporated where feasible: grading impervious driveways and paving to drain toward planted areas, minimizing paved surface area, using pervious pavers or porous concrete, routing roof and paved-surface runoff into planting beds, and installing rain gardens, cisterns, and other rain harvesting or catchment systems, plus infiltration beds, swales, basins, and drywells.
3 gives a real incentive for on-site rainwater capture: if graywater or stored on-site rainwater alone meets a lot's entire landscape water requirement on a parcel under 2,500 square feet, that project only has to complete the streamlined Water Efficient Landscape Worksheet instead of the full landscape documentation package otherwise required under subsection D.
Violations & Fines
There is no separate rainwater-harvesting fine schedule; a landscape plan that fails to meet the Section 17.03.020(Q) capture and infiltration standards is enforced the same way as any other Water Efficient Landscape Ordinance deficiency, through withheld plan approval, a withheld certificate of completion, or a withheld occupancy clearance from the Director of Community Development until the grading and landscape design comply, and separately through Chapter 18.04 stormwater enforcement for runoff exceeding the design storm.
Frequently Asked Questions
Does Norwalk require rain gardens or cisterns on new landscaping?
Can capturing rainwater on-site reduce my landscape permit paperwork?
How does rainwater harvesting connect to Norwalk's stormwater rules?
Sources & Official References
Other rules in Norwalk
California rules heatmap·Compare Norwalk to another location·View the California landscaping rules overview
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