Sunnyvale, CA Environmental Rules: Stormwater Management (2026)

Section 12.60.070 of the Sunnyvale Municipal Code states a "general prohibition" that "any discharge to the storm drain system not composed entirely of stormwater is prohibited, except as set forth in this chapter," and separately makes it unlawful to throw, deposit, leave, abandon, maintain or keep materials or wastes anywhere they may cause an illicit discharge. The chapter, enacted to implement the city's NPDES municipal stormwater permit issued July 1, 2022 and its Clean Water Act and Porter-Cologne Act obligations, applies to all water entering the storm drain system from every developed and undeveloped parcel in Sunnyvale (SMC 12.60.010, 12.60.020).

Several categories are exempt: discharges under a facility-specific NPDES or Regional Water Quality Control Board permit, discharges under the state general industrial or construction stormwater permits, and "categorically allowed" non-stormwater flows such as riparian habitat flows, diverted streams, natural springs and uncontaminated groundwater infiltration. A second, longer list, including foundation and footing drains, air conditioning condensate, landscape irrigation, residential car washing and swimming pool water, is only "conditionally exempt" and requires the discharger to install and maintain applicable minimum best management practices from the NPDES permit (SMC 12.60.070(f)).

Any exempt category that turns out to be a significant pollutant source can still be prohibited on a schedule set by the enforcement official (SMC 12.60.070(h)). Violations are a declared public nuisance under Section 12.60.360, and the Director may issue a verbal or written warning notice or notice of violation requiring correction before the next rain event or within ten business days, whichever applies (SMC 12.60.370(a)). Civil penalties under Government Code Section 54740.5, assessed by the Director of Public Works, Community Development or Environmental Services, run from $2,000 per day for failing to submit monitoring reports up to $10,000 per gallon for discharges violating a suspension or cease-and-desist order (SMC 12.60.380(b)).