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Stormwater Quality Protection
Leaf clogged storm drain

Stormwater Quality Protection

People in Boulder County enjoy our streams for their beauty and recreation, and rely on our streams for clean drinking water, growing healthy food, and economic vitality. These waterways are also home to a diversity of aquatic life that depend on clean water to live.

As water from rainfall or snowmelt flows over rooftops, roads, and yards, it picks up and carries pollutants such as fertilizers, soap, oil, dirt, metals, and solvents that then becomes stormwater pollution. This pollution is carried to the storm drainage system, which flows untreated into our local creeks and streams harming water quality and aquatic life. Stormwater pollution is particularly important in Boulder County’s semi-arid climate where water is scarce.

Learn more about common pollutants and steps to keep our water clean at Keep It Clean Partnership.org

Report a Concern

Boulder County’s Role

Boulder County works with businesses, agencies, and individuals to foster shared responsibility for the health of our waterbodies.

Municipal Separate Storm Sewer Permit (MS4)

Boulder County holds a Federal Clean Water Act and Colorado Water Quality Control Act permit (COR090000) that requires Boulder County to protect stormwater quality by:

  • Establishing organizational control
  • Encouraging public involvement and participation in stormwater quality activities
  • Providing public education and outreach
  • Detecting and eliminating illegal discharges of pollutants into storm drains
  • Overseeing construction practices to ensure pollutants don’t enter storm drains
  • Ensuring stormwater infiltrates into the soil or flows into a water quality treatment facility, as applicable
  • Preventing stormwater pollution from county operations

Program Description Document

The MS4 Permit requires Boulder County to develop and follow Program Description Documents (PDDs) that describe how the County’s program works. These Program Descriptions are designed to consolidate recordkeeping and other requirements, and also serve as a set of useful procedures for County staff.

Contact the Stormwater Quality Program Manager to review the most up-to date versions.

Links to each program areas are provided below.

Public Involvement & Participation

Boulder County notifies the public of any proposed stormwater quality ordinance changes by publishing the proposed ordinance in the newspaper, holding a public hearing before the Board of County Commissioners, and posting the approved ordinance and other program updates here. Boulder County also welcomes feedback on the Program Descriptions.

Public Education & Outreach

Boulder County has developed an education and outreach strategy and is one of the seven member communities of the Keep it Clean Partnership, a collaborative organization formed in 2003 which focuses on water quality protection and enhancement. The Keep it Clean Partnership conducts public education and outreach at schools, community events, and through advertising.

Detecting and Eliminating Illegal Discharges

Boulder County Public Health detects and eliminates pollution from entering Boulder County storm drains as part of the Boulder County Illegal Discharge Ordinance, our local clean water act.

Residents and visitors can help by reporting pollution entering storm drains and waterways.

Things to look for include:

  • An unusual color of the water
  • An unusual or foul odor
  • Suds or puddles when there has not been recent precipitation
  • Any unusual-looking substance leaving the storm drain
  • Illegal dumping of waste near storm drains (e.g., household chemicals, automobile fluids)
  • A large number of dead or dying animals including fish, crayfish, insects, waterfowl or other animals near a waterbody

Report a Concern

To verify if a concern is in unincorporated Boulder County, use the Property Search tool to determine the location before submitting your report. See Stormwater Quality Reporting Numbers for stormwater pollution concerns in cities and towns.

Overseeing Construction Practices & Permanent Structures to Treat Stormwater

Construction activities disturb the vegetation and natural soils of a site, resulting in increased soil erosion, sedimentation, and other forms of pollution. Sediment that washes off a construction site can end up in waterways where it destroys aquatic habitat. The Boulder County Public Works Department protects waterways by ensuring construction projects effectively control pollution as part of the Stormwater Quality Permit Ordinance (Article 7-904) and implementation of the Stormwater Quality Permit.

Preventing Stormwater Pollution from County Operations

Boulder County Public Health provides technical support to ensure county departments implement stormwater quality protection practices in their facilities, projects, and daily activities.


Boulder County reports stormwater protection activities and outcomes to the Colorado Department of Public Health and Environment (CDPHE) each year in March.

Annual Reports

Hotline Information

Report non-emergency concerns about illegal discharges using the buttons on this page. All emergency or hazardous spills should also be reported to 911.

Contact Us

Water Quality Program

Main: 303-441-1564
Submit a question


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