Boulder, CO Environmental Rules: Stormwater Management (2026)
Key Facts
- Erosion control permit
- Required before any construction activity
- Permit lapse
- Void after 180 days unused or suspended
- Large disturbance threshold
- 1 acre triggers CDPS + SWMP filing
- SCM inspection
- At least once per year, owner's duty
- Record retention
- 5 years of SCM maintenance records
- Civil penalty schedule
- $100 / $300 / $1,000 per violation
Summary
Boulder requires an erosion control permit before any ground-disturbing construction and a city-approved final drainage report before a building permit issues. Property owners fund the Stormwater and Flood Management Utility through fees, and on-site detention facilities must be inspected yearly under Municipal Code Chapter 11-5.
(b)Erosion Control Permit Required: No person shall commence construction activities before obtaining an erosion control permit.(1)Compliance With Permit Required: No person shall fail to conduct construction activities consistent with the approved erosion control permit and the requirements of this chapter and the City of Boulder Design and Construction Standards.(3)Expiration: All construction activities covered by the permit shall be completed by the date approved in the permit. Permits shall expire and be void if the activities authorized by the permit have not commenced within 180 days after its issuance, or if the activities authorized by the permit are suspended or abandoned for a period of 180 days. The city manager may grant in writing one or more extensions of time for periods not to exceed 180 days each if the applicant demonstrates justifiable cause in writing.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 167 Update 3).
Full Breakdown
C. 1981, ties development approval directly to drainage compliance. 13 of the City of Boulder Design and Construction Standards. Permits expire if construction has not started, or is suspended, for 180 days, though the city manager may grant written extensions of up to 180 days each for justifiable cause. Before a building permit issues, Section 11-5-6(c) requires a detailed final drainage report meeting state, federal and city standards, and any subdivision or site review approval is conditioned on that report. Owners of stormwater control measures (SCMs) must keep them operational, inspect them at least once a year, and retain five years of maintenance records available to the city manager on request.
Section 11-5-3 requires the city manager to maintain a council-adopted master drainage plan mapping drainage basins and facilities, updated through public hearings for new projects. Section 11-5-5 bars illicit discharges into the storm sewer system, streets, or watercourses, with limited listed exemptions (irrigation, dechlorinated pool water, firefighting, agricultural runoff, and similar low-risk flows). C. 1981, except for entirely undeveloped parcels.
Violations & Fines
The city manager may issue a written notice of violation with a reasonable cure period; failure to correct it (or an emergency) lets the city fix the problem and bill the owner. After notice and a quasi-judicial hearing, the manager may impose civil penalties on an escalating schedule: $100 for a first violation of a provision, $300 for a second violation of the same provision, and $1,000 for a third, with each day of continuing violation a separate offense (Section 11-5-22). The city attorney may separately prosecute violations as a municipal offense under the general penalty in Section 5-2-4, or sue in Boulder County District Court for damages, injunctive relief, or specific performance (Sections 11-5-23, 11-5-24).
Frequently Asked Questions
Do I need a permit before digging or grading in Boulder?
How long is a Boulder erosion control permit valid?
What happens if I violate Boulder's stormwater rules?
Do I have to maintain my detention pond or water quality device?
Sources & Official References
Other rules in Boulder
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Stormwater Management in Nearby Cities
How other cities in Boulder County handle stormwater management.