California Code of Regulations
Title 23 - Waters
Division 2 - Department of Water Resources
Chapter 2.7 - Model Water Efficient Landscape Ordinance
Section 492.16 - Stormwater Management and Rainwater Retention
Current through Register 2024 Notice Reg. No. 38, September 20, 2024
(a) 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.
(b) Project applicants shall refer to the local agency or Regional Water Quality Control Board for information on any applicable stormwater technical requirements.
(c) All planted landscape areas are required to have friable soil to maximize water retention and infiltration. Refer to § 492.6(a)(3).
(d) It is strongly recommended that landscape areas be designed for capture and infiltration capacity that is sufficient to prevent runoff from impervious surfaces (i.e. roof and paved areas) from either: the one inch, 24-hour rain event or (2) the 85th percentile, 24-hour rain event, and/or additional capacity as required by any applicable local, regional, state or federal regulation.
(e) It is recommended that storm water projects incorporate any of the following elements to improve on-site storm water and dry weather runoff capture and use:
* Grade impervious surfaces, such as driveways, during construction to drain to vegetated areas.
* Minimize the area of impervious surfaces such as paved areas, roof and concrete driveways.
* Incorporate pervious or porous surfaces (e.g., gravel, permeable pavers or blocks, pervious or porous concrete) that minimize runoff.
* Direct runoff from paved surfaces and roof areas into planting beds or landscaped areas to maximize site water capture and reuse.
* Incorporate rain gardens, cisterns, and other rain harvesting or catchment systems.
* Incorporate infiltration beds, swales, basins and drywells to capture storm water and dry weather runoff and increase percolation into the soil.
* Consider constructed wetlands and ponds that retain water, equalize excess flow, and filter pollutants.
1. New section filed 9-10-2009; operative 9-10-2009 pursuant to Government Code section 11343.4 (Register 2009, No. 37).
2. Renumbering of former section 492.16 to section 492.17 and renumbering of former section 492.15 to new section 492.16, including amendment of section heading, section and NOTE, filed 9-15-2015; operative 9-15-2015. Exempt from OAL review and submitted to OAL for printing only pursuant to Governor's Executive Order No. B-29-15 (4-1-2015) (Register 2015, No. 38).
Note: Authority cited: Section 65595, Government Code; and sections 11 and 30, Governor's Exec. Order No. B-29-15 (April 1, 2015). Reference: Section 65596, Government Code; and section 11, Governor's Exec. Order No. B-29-15 (April 1, 2015).
