Hercules, CA Environmental Rules: Stormwater Management (2026)
Key Facts
- Governing chapter
- HMC Title 5, Chapter 8
- Impervious-surface trigger
- 10,000 sq ft (since 8/15/2006)
- NPDES permit number
- CAS0029912
- Trash capture install deadline
- 4 months after notice
- Compliance certificate term
- 1 year
- Misdemeanor penalty cap
- Gov't Code Section 36901 limits
Summary
Hercules bans any non-stormwater discharge into its storm drains and requires a City-approved stormwater control plan for projects that add 10,000 square feet or more of impervious surface. The rules implement the City's NPDES Permit No. CAS0029912 under Municipal Code Chapter 5-8.
Sec. 5-8.050. Stormwater Control Plan Required. (a) Every application for a development project, including but not limited to a rezoning, tentative map, parcel map, conditional use permit, variance, site development permit, design review, or building permit that is subject to the development runoff requirements in the City's NPDES permit shall be accompanied by a stormwater control plan that meets the criteria in the most recent version of the Contra Costa Clean Water Program Stormwater C.3. Guidebook. ... (2) Effective August 15, 2006, this requirement shall apply to: A. All developments that create ten thousand (10,000) square feet or more of impervious surface.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 555, passed March 25, 2025).
Full Breakdown
Chapter 8 of Title 5 protects local watercourses under the Porter-Cologne Water Quality Control Act and the federal Clean Water Act. 3 Guidebook; the threshold dropped from 1 acre of new or replaced impervious surface (effective February 15, 2005) to 10,000 square feet (effective August 15, 2006), with a single-family home exclusion. 060 bans releasing non-stormwater discharges into the City system outright, exempting only NPDES-permitted flows and natural groundwater or riparian flows. 090 requires paved parking lots, gas stations and private streets to be cleaned regularly and to install a full trash capture system within four months of written notice from the Director, defined in the Code as the City Manager or designee.
100 requires anyone with a stormwater management facility to obtain an annual operation-and-maintenance Certificate of Compliance, valid for one year, after a City inspection and fee payment; the City may instead accept a private inspection report filed under penalty of perjury, and a false report is a misdemeanor. 110 lets any officer inspect premises, sample discharges, and coordinate with agencies like the Contra Costa Mosquito and Vector Control District or the Regional Water Quality Control Board.
Violations & Fines
Under Section 5-8.120, any violation of Chapter 8 is a misdemeanor, though the enforcing officer or City Attorney may instead charge it as an infraction. Section 5-8.130 caps a misdemeanor fine or jail term at the limits in California Government Code Section 36901, and an infraction fine at the limits in Government Code Section 36900. Each day a violation continues is a separate offense under Section 5-8.140, the City can also pursue a civil injunction and recover investigation, cleanup and monitoring costs under Section 5-8.180, and Section 5-8.170 declares a violating condition a public nuisance subject to abatement.
Frequently Asked Questions
Do I need a stormwater plan for a small home addition in Hercules?
Can I hose oil or soapy wash water into a Hercules storm drain?
Who inspects stormwater facilities in Hercules?
What happens if I violate the stormwater ordinance in Hercules?
Sources & Official References
Other rules in Hercules
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