photo credit

The City of Westminster operates a stormwater utility to serve its residents. North of 92nd Avenue, all stormwater accumulated from paved surfaces ultimately flows into Big Dry Creek. South of 92nd Avenue, all accumulated stormwater ultimately flows into Little Dry Creek.

The primary goal of the City's stormwater program ("program") is to reduce the amount of pollutants entering Little Dry Creek and Big Dry Creek. Pollutants such as fertilizers, pesticides, sediments, hydrocarbons, trash and spilled chemicals may be transported by storm water from residential, commercial and industrial areas into the storm sewer system that ultimately ends up in our local waterways, causing water pollution.  

The purpose of the program is to protect natural resources, ensure public safety and continue to improve the quality of life of all residents. Per the Municipal Separate Storm Sewer System (MS4) General Stormwater Permit issued by the Colorado Department of Health and Environment (CDPHE), the City must develop and maintain records of the program in the form of a Program Description Document (PDD). A copy of the PDD is available for public comment and review.  

Contact Heather Otterstetter at with any inquiries.

Click here to read the Stormwater 2021 Annual Report.

MS4 permit area map


Current Projects: 

Big Dry Creek Streambank Restoration Project

  • Westcliff Parkway to Wadsworth Boulevard

  • City Park 

  • Sheridan Boulevard to 112th Avenue 


Learn about the Value of Water


One of the many goals of the Stormwater Program is to increase public awareness of local water quality problems caused by urban environments. This ranges from education, to helping individuals change their daily actions, to community activities supporting the stormwater program. This program takes into account pollutants commonly associated with the urban environment.

What is the difference between the sanitary sewer system and storm sewer system?

Are you polluting without knowing it?

Learn about common stormwater pollutants

How can you prevent excess nutrients in stormwater?

Find out about the Poop Fairy!

Learn about the Mile High Flood District!!

2018 Stormwater Annual Report 

2019 Stormwater Annual Report

2020 Stormwater Annual Report

Public participation/involvement is often discussed in the context of the public education measure because they share a common goal – reaching out to citizens to improve awareness and achieve program compliance. The distinction between the two programs is that public participation/involvement provides a conduit for citizens to participate in the development and implementation of the publicly funded stormwater program.

City Events  

Environmental Advisory Board

Adopt a street

How You Can Help Protect Water Quality:

  • Keep it out of the inlet: Grass clippings, leaves, dog waste, oil and paint are all pollutants that degrade water quality.  ONLY RAIN DOWN THE DRAIN.
  • Test your soil/Read the label: Over-fertilizing can hurt your lawn and negatively affects water quality.
  • Pick it up: Dog waste is a source of bacteria in waterways.
  • Avoid the driveway - Go to a car wash: Water from a car wash is recycled and treated.
  • Vehicle Maintenance: Small fluid leaks can have a big impact on water quality.  For example, only one gallon of oil can contaminate a million gallons of water.
  • Household chemicals: Store hazardous chemicals in the shed, garage, or somewhere out of the rain.  Use your local Household Hazardous Waste facilities and drop-off events to ensure unused household chemicals are properly disposed.  Are you a Westminster resident?  Have those chemicals picked up at your door with the City's Household Hazardous Waste Collection Program.
  • Trash also counts: Trash is also a source of water pollution, so keep it in the can!


Have you ever wanted to walk all 163 miles of waterways throughout the City of Westminster?  Well, look no further! The City has partnered with FishViews to bring you a "street" view of every mile of waterway in the city.  This type of study has never been done before in an urban setting and will change the way you look at drainageways. FishViews will allow you to navigate the waterways from your computer or mobile device - revolutionizing the way people gather, analyze and communicate location-based data.  Explore here!

Illicit discharge is in essence illegal dumping. The goal of the Illicit Discharge Detection and Elimination Program is to reduce the frequency and impact of illicit discharges to the environment in which pollutants are intentionally or accidentally discharged into the storm sewer system. Documentation and supplementary material will provide greater insight to the process of illicit discharge elimination and types of illicit discharges and enforcement procedures laid out by the City of Westminster.

Find out more about Illicit Discharges

Which businesses are more likely to illegally discharge?


You can report any probable illicit discharge by calling our Stormwater Hotline at 303-706-3367 or by emailing  Please provide the location, responsible party (if identified), and a description of the source and nature of the illicit discharge.

*Please note that City Hall hours are Monday through Thursday 7 a.m. to 6 p.m. If your report occurs outside of these hours, please leave a voicemail or email and the city will respond within these business hours. If you feel that the report is an emergency that needs immediate response, please call Westminster dispatch at 303-658-4360.   

The goal of the Construction Sites Compliance Program is to reduce sediment and other construction-related pollutants from entering the Municipal Separate Storm Sewer System (MS4). The city is committed to the enhancement and protection of existing development, streams, lakes, wetlands and rivers that may be impacted by sediment laden runoff and encourages builders to maintain the natural balance between sediment supply and transport.

It is also the city's policy to encourage erosion control by leaving land undisturbed as long as possible (by project phasing) and using temporary and permanent erosion control Best Management Practices (BMPs).  BMP details can be found in Volume 3 of the Urban Storm Drainage Criteria Manual on the Mile High Flood District's website.

Under city code, the City of Westminster has the authority to issues Notices of Violation (NOV's) as well as Stop Work Orders for any developer or contractor that does not comply with sediment and erosion control measure requirements. All of our stormwater information related to construction sites can be found through eTrakIT.  Here is a list of contractors in 2021 that have a list of violations along with their respective eTrakIT identifications.

  • Hinton Construction Co (Orchard at Westminster Filing #6) - ENG19-0005
  • Martines Palmeiro Construction (Westglenn Subdivision Filing #5) - ENG19-0007
  • Northern Colorado Constructors (North Huron Interceptor Sewer Replacement) - ENG20-0027
  • Shaw Construction (Millennium Circle Point) - ENG20-0003
  • Shaw Construction (Westminster ROW) - ENG19-0014
  • St. John Properties, Inc. (Olson Technological Park - Lot 3B) - ENG20-0016

Although the City of Westminster is fairly strict concerning construction site non-compliance; we do pride ourselves on our compliance assistance within the program. City officials are here to serve the community and help in any way that we can, which is why our city inspectors are trained to not only point out issues with particular sites, but also help toward fixing these issues surrounding compliance in a way that can strengthen our community and culture in relation to the environment.  Supplemental material has been provided in the space below related to city expectations for construction compliance.

Westminster Stormwater Program Guidance Document

Apply for a Land Disturbance Permit

Land Disturbance Permit Submittal Requirements

Land Disturbance Permit Modification Form

Westminster Land Disturbance Permit (LDP) Kickoff and Initial Inspection

Stormwater Management Plan (SWMP) Template

Westminster Stormwater Review Checklist

Training Opportunities

* A Microsoft Word version of the Stormwater Management Plan (SWMP) template is available upon request.  Please email Heather Otterstetter at

The goal of the Post-Construction Compliance Program for the City of Westminster is to implement planning procedures and enforcement mechanisms to reduce stormwater impacts resulting from areas of new development and significant redevelopment. 

Private stormwater treatment facilities, such as extended detention basins, low impact development technologies and underground storage tanks must be properly installed and maintained. The City of Westminster Engineering Division works directly with developers, homeowners associations, private property managers, and commercial property owners to achieve this goal. Long-term maintenance of drainage structures is needed to ensure systems continue to function per designed, preventing flooding, erosion and water quality degradation of our local lakes and streams.

Owners are required to inspect and maintain these stormwater treatment facilities. Inspections and repairs must be documented and available upon request. Additionally, businesses operating on the property are not allowed to discharge anything but naturally occurring stormwater runoff into the stormwater system. This includes preventing materials stored outside from leaking, draining, spilling or being dumped into the stormwater system. 

For Developers/Design Engineers: 

Post Construction Stormwater Management Design Standards Form

Post Construction Stormwater Management Exclusions Form

Operation and Maintenance Manual Template - Extended Detention Basins

Operation and Maintenance Manual Template - Porous Landscape Detention

For Contractors:

Extended Detention Basin Inspection Procedures

Porous Landscape Detention Inspection Procedures

Stormwater Treatment Facility Inspection Software Procedures

For Property Owners:

Post Construction Maintenance Form

Westminster Operating and Maintaining Detention Ponds Field Guide 

Routine Extended Detention Basin Maintenance Video

Landscape Contractor Training Pamphlet

Inspection and Maintenance Training Opportunities

Certified Professionals

The goal of the Pollution Prevention/Good Housekeeping for Municipal Operations Program is to reduce the amount and type of pollution that is generated by municipal operations or from municipally-owned property such as sediment, hydrocarbons, trash and debris, nutrients and metals.  The City of Westminster’s goal is to set an example in the community by preventing stormwater pollution while carrying out numerous municipal activities that have the potential to impact water quality.  These activities include, but are not limited to the maintenance and repair of city streets, the maintenance of public parks and recreational areas, and the maintenance of municipal facilities.

Fact Sheet    

Stormwater questions:

Heather Otterstetter, P.E,

Andrew Hawthorn, P.E.