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San Bernardino County, CA Environmental Rules: Stormwater Management (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified August 2026

Key Facts

Governing law
County Code § 35.0118
Trigger
Projects covered by MS4 permit
Enforcement
Director of Public Works
Max civil fine
$2,500 per day, per offense
Applies to
Unincorporated County only

Summary

Development projects in unincorporated San Bernardino County must submit a Water Quality Management Plan with structural BMPs before discharging runoff to the storm drain system.

City-specific rules exist: Chino, Victorville, Hesperia, Fontana, Rancho Cucamonga, Ontario, San Bernardino, and Rialto have their own stormwater management rules that differ from San Bernardino County's county-level regulations. If you live in one of those cities, check the city-specific page instead.

A WQMP shall be prepared and submitted to the authorized representative for all projects subject to this requirement under the applicable MS4 permit. The WQMP shall include proposed structural BMPs as required in the applicable MS4 permit... In developing a WQMP, the owner(s)/user(s) shall demonstrate that the proposed structural BMPs will infiltrate, and/or adequately treat, the projected storm water and urban runoff for the development project.

Source: San Bernardino County Stormwater ProgramView official code

Full Breakdown

Under County Code Chapter 35, any project that triggers the countywide MS4 permit must prepare a Water Quality Management Plan (WQMP) with structural best management practices to infiltrate or treat storm water and urban runoff, plus a signed maintenance schedule. Owners must also record a legally enforceable maintenance agreement with the County before connecting to the Storm Drain System, and that obligation runs with the land to successors and HOAs. The Director of Public Works or a Code Enforcement Officer administers the program under the Clean Water Act and the Regional Water Quality Control Board's NPDES permit.

Violations & Fines

Civil fines up to $2,500 per day per offense against industrial/commercial users, plus attorney's fees and litigation costs; willful or knowing violations are criminal, from a $50-$100 first-offense infraction up to a misdemeanor with a $500-$1,000 fine and up to six months in jail.

Frequently Asked Questions

Does every new home need a WQMP in San Bernardino County?
Only projects that trigger coverage under the applicable MS4 permit; the County's authorized representative determines applicability at plan submittal.
Who stays responsible for BMP maintenance after a sale?
The new owner, since County Code § 35.0119 requires the maintenance obligation to run with the deed to successors, assigns, or an HOA.

Sources & Official References

Other rules in San Bernardino County

All San Bernardino County rules

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