The rivers and streams that flow through Denver, including the South Platte River and Cherry Creek, and the lakes within the City's borders, such as Sloans Lake and Ferril Lake in City Park, are some of Denver’s most important resources. Achieving and sustaining good water quality in Denver's lakes and streams is beneficial to the people who live in Denver and to the plant and animal communities along and in our lakes and streams. Good water quality is also important for the health of our residents, the economic well-being of Denver, and for our overall quality of life.

• Why is Water Quality so Important?
  • The South Platte River Watershed
  • Point vs. Non-point Source Pollution
  • Recreation & Bacteria
    • South Platte-Cherry Creek confluence
    • Sloans Lake
    • Bear Creek 
  • Fish Consumption Advisories
• How Can I Help Improve Water Quality?
• Glossary of Water Quality Terms
• Reports available online
• Mayor's Water Quality Initiative 
• Stormwater Inspections 
• Other Useful Links

Water Quality and the Denver Department of Environmental Health

The Denver Department of Environmental Health’s Environmental Quality Division (EQ) has been involved in water related issues for over 25 years. EQ’s involvement in water related issues was initially intended to identify and remove illicit connections to the storm sewer system within the City and County of Denver; however, the purpose of the sampling program has evolved over the years to include many other water aspects.

Contact Us

If you notice any of the following unusual conditions in any of the lakes and streams in Denver please call EQD at (720) 865-5452 or email eqcomments@ci.denver.co.us:

• A change in color of the water
• An unusual or foul odor
• Suds when there is no precipitation occurring
• Any unusual-looking substance discharging from a storm outlet
• Illegal dumping activity
• Unusual discharges from construction sites or industrial sites
• Large number of dead or dying fish or crayfish

All information you submit is confidential.

Special Notices

Information on West Nile Virus can be found at the Department of Environmental Health's Division of Animal Care and Control and at Fight the Bite.

ATTENTION: Swimming or playing in city lakes and streams is not advised. At any given time, Denver's waters can contain high amounts of bacteria or other contaminants that are harmful to human health. Ingesting water from city lakes and streams could cause you to become ill. Swimmers are encouraged to use the swimming facilities provided by the Denver Parks and Recreation Department throughout the city. Kayakers may also become ill from ingesting surface water.