SW

Stormwater Directory

Colorado

Colorado Department of Public Health and Environment, Water Quality Control Division

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Quick Summary

For most Colorado projects disturbing 1 acre or more, you need an NPDES Construction General Permit, a SWPPP, and a state-certified Stormwater Management Professional Inspector (SMPI) on site. The annual permit fee is $340.

State-DelegatedVerified 2026-03

Construction Permit

Permit Document ↗
Permit Name
Construction Dewatering and Stormwater General Permit (COR400000)
Threshold
≥ 1 acre of land disturbance (or < 1 acre if part of a larger common plan of development exceeding 1 acre)
NOI Lead Time
Stormwater Management Plan (SWMP) must be developed before construction; permit coverage active upon filing NOI
Application Method
Online via CDPHE's Stormwater Compliance Assistance Program (SCAP) portal
Fee
$340 annual fee; $170 for < 1 year of coverage
Permit Expires
June 30, 2027
Apply for Permit ↗

SWPPP Requirements

Permit Document ↗
SWPPP Required
Yes
PE Cert Required
No
Template Available
Yes
Colorado refers to the SWPPP as a Stormwater Management Plan (SWMP). The SWMP must be prepared by a Stormwater Management Plan Designer — no professional engineer stamp is required by the state, but some local jurisdictions require it.

Inspection Requirements

Permit Document ↗
Frequency
Every 14 days and within 24 hours of precipitation events producing ≥ 0.5 inches (or ≥ 0.1 inches in the semiarid zone)
Rain Trigger
Within 24 hours of a precipitation event producing ≥ 0.5 inches (≥ 0.1 inches in designated semiarid zones)
Inspector Qualification
Stormwater Management Plan Inspector (SMPI) — must complete CDPHE-approved training course. Certification must be renewed every 3 years.
Accepted Certifications
No state-specific cert required; CDPHE requires a trained 'SWMP Administrator'; CPESC, CESSWI accepted; CDPHE-approved training recommended

Discharge Standards

Permit Document ↗
Turbidity Limit
Not specified as a numeric limit in the General Permit; discharges must comply with narrative water quality standards
High-altitude and semiarid conditions in Colorado create unique stormwater challenges. Projects near Outstanding Waters of Colorado (OWC) or impaired streams have additional restrictions.

Post-Construction

CDPHE WQCD ↗
Required
Yes
Post-construction requirements are primarily handled at the local level through MS4 programs. Many Colorado municipalities (Denver, Boulder, Fort Collins) have adopted specific Low Impact Development (LID) standards.

Impaired Waterbody / TMDL Requirements

Elevated Risk

Colorado's CDPS Construction Stormwater Permit includes provisions for TMDL compliance. Projects discharging to impaired water segments must not cause or contribute to exceedances of water quality standards and must comply with applicable Waste Load Allocations from approved TMDLs. Projects in the Cherry Creek, Bear Creek, and other TMDL-subject watersheds may face specific additional conditions. Verify applicable TMDLs through CDPHE's Basin Roundtable resources.

Program Contact

Contact Page ↗
Phone
(303) 692-3517
Email
cdphe_wqcd_permits@state.co.us

State-Specific Notes

Colorado requires a state-certified SMPI for inspections, making it one of the few states with a mandatory inspector certification program. Altitude and arid conditions affect BMP effectiveness — conventional sediment controls perform differently than in humid climates.

Disclaimer: This information is provided for general reference only and may not reflect the most current regulatory requirements. Always consult the CDPHE WQCD website and applicable regulations before beginning any construction activity.