State Water Resources Control Board holds public Q&A on proposed stormwater infiltration policy

State Water Resources Control Board staff held a public question-and-answer webinar on a proposed statewide stormwater infiltration policy, outlining how the policy could be implemented through municipal stormwater permits and answering technical and legal questions from engineers, groundwater agencies and other stakeholders.

The session focused on how the policy would be applied and regulated, including whether it would be implemented through MS4 municipal stormwater permits, how setbacks and monitoring would be determined, and how the policy would coordinate with other state and federal programs. Staff said the board aims to issue a draft for public comment by the end of 2025.

The board’s presenters described the policy as a risk-based, statewide starting point intended to make infiltration projects clearer and more feasible. State Water Resources Control Board staff Kelly said, “Our goal is to not reduce streamflows. Our goal is to manage the stormwater that is kind of extra to those base flows.” Staff acknowledged limits to the board’s authority and said the policy is not intended to override local engineering analysis or other agencies’ responsibilities.

Participants raised technical and programmatic concerns. Several speakers asked whether the policy would apply to small priority development projects included in MS4 permit requirements; State…