Urban Stormwater Infiltration Policy
Supporting stormwater management agencies in prioritizing stormwater capture and groundwater recharge as a method of increasing water supplies is an important component of diversifying and improving California’s water supplies. This statewide infiltration policy will expand on the existing 2020 drywell guidance framework to provide clear, science-based direction on urban stormwater infiltration best practices while protecting groundwater quality and beneficial uses.
Project Contact Information
Kelly.Rodman@Waterboards.ca.gov
(916) 323-0882
What's New
No updates at this time.
Project Description
Project Objective
This project will result in a State Policy for Water Quality Control for urban stormwater infiltration (Policy). The proposed new Policy will encourage infiltration of urban stormwater to increase groundwater recharge and strengthen local water supply resiliency, provide greater protection to surface water quality, and develop projects with multiple benefits for communities. The Policy will also prohibit infiltration under inappropriate conditions where beneficial uses of groundwater may be impacted.
Project Benefits
- Clear science-based direction on urban stormwater infiltration best practices.
- Protection of groundwater quality and beneficial uses.
- Identification of data gaps and recommended next steps to fill those gaps.
- Protection of surface water quality through infiltration of stormwater runoff that would otherwise discharge to surface waters.
- Address regulatory inconsistency in current permits and local ordinances that results in confusion about where, when, and how to implement stormwater infiltration projects.
Background
The Strategy to Optimize Resource Management of Stormwater (STORMS) promotes stormwater as a valuable resource because the capture and use of stormwater can provide multiple benefits to watersheds, including improved municipal water supply resiliency. Groundwater recharge via stormwater infiltration is a viable option for storing harvested stormwater long term, especially in the semi-arid climates occurring in many regions of California. However, a lack of a cohesive regulatory framework and a lack of clarity about water quality objectives related to stormwater capture and infiltration are obstacles to wide-scale implementation of stormwater capture and use. Stormwater infiltration projects will continue to be constructed by permittees to meet permit requirements and replenish groundwater resources in drought-stricken areas. Therefore, it is important to develop policies, guidance, and best practices that protect groundwater quality for all applicable beneficial uses, while encouraging the implementation of stormwater infiltration projects.
