San Francisco, CA Environmental Rules: Stormwater Management (2026)

2, measures projects by the impervious surface they create or replace. 2(a). Because replaced surface counts alongside new surface, repaving an existing area can trigger the rule even when a site's footprint never grows. 2(b): it must submit a Stormwater Control Plan for review and approval by the General Manager. The subsection then locks the rest of San Francisco's permitting machinery to that approval. No City department may approve or issue a permit to construct the project, including a building or site permit, unless and until the plan has been developed and approved.

That makes the stormwater plan a prerequisite sitting upstream of the entire permit chain, so a large project cannot collect its other approvals first and leave drainage design for later. Alongside the project-level rules, unauthorized drainage connections and pollutant discharges are separately prohibited under Public Works Code Sections 133 and 134.