Protecting Denver's Water Quality

Denver’s goal is to have fishable and swimmable waters in all our lakes and streams. Denver’s Departments of Public Health and Environment (DPHE), Transportation and Infrastructure (DOTI), and Parks and Recreation are all working hard to ensure the city meets that goal. Here are a few things the city is doing to improve water quality:

  • DDPHE samples the South Platte River and its tributaries to determine the impact of urbanization on water quality.  Monitoring is also conducted to determine if there are any public health risks associated with recreating in streams and lakes in Denver. Additional sampling of Denver’s lakes informs maintenance and management decisions. 
  • DDPHE assess the effectiveness of actions taken by other city agencies to improve water quality.  Information from those assessments ensures that actions are effective, helps improve the design of future water quality interventions, and provides a better understanding of maintenance requirements.
  • DOTI performs routine maintenance on storm and sanitary sewers to eliminate cross connections and remove blockages. To date, the program has successfully reduced the amount of bacteria entering the South Platte River from the city’s storm sewers.
  • DOTI has identified areas where more facilities are needed to ensure storm water runoff is adequately treated to remove sediment, trash, and other pollutants. That information has been used to develop an implementation plan which describes and prioritizes opportunities for installation of water quality treatment facilities. Learn more about Green Infrastructure in Denver. Information about facilities which have already been installed can be on the Green Infrastructure Story Map.
  • Parks and Recreation manages most of the city's lakes. Parks has many initiatives to improve water quality.  Those initiatives include:
    • Reducing fertilizer use to reduce nitrogen and phosphorus in runoff from parks,
    • Installing water column aeration systems in lakes to improve habitat for fish and to reduce the impacts of algal growth, and
    • Planting vegetation and implementing no-mow zones along lakes and streams to provide water quality treatment for runoff.

Things You Can Do to Protect Water Quality

Keeping Denver's lakes and streams clean requires everyone’s help. Runoff carries oil, chemicals, pesticides, fertilizers, pet waste, debris and sediment directly into storm sewers, streams and lakes without treatment. Residents can help by taking a few precautions and changing habits in small but noticeable ways. Every individual action adds up, and every individual can make a difference. 

Here are things residents can do to help keep Denver's streams and lakes clean:

  • Take a pledge to protect Denver's lakes, streams and wetlands.
  • Dispose of garbage in a trash receptacle, not on the ground or in the gutter.
  • Pick up after pets and place the waste in a trash receptacle.
  • Apply fertilizer and pesticides in accordance with manufacturer's recommendations.
  • Don't apply fertilizer and pesticides before a storm.
  • Use phosphorus-free fertilizer.
  • Make sure vehicles are properly maintained to minimize leaks and drips.
  • Wash vehicles at a car wash, not in driveways or streets.
  • Dispose of household and hazardous chemicals (such as paint, pesticides or vehicle oil) properly. For information on disposal, visit Denver's Household Hazardous Waste Collection Program or call to schedule a pick up at 1-800-HHW-PKUP (800-449-7587).
  • Dispose of unwanted medicine and prescriptions at a medication take-back event. To find the next take back event near you or to find medication disposal locations, visit Take Meds Seriously’s Safe Disposal website.
  • Volunteer to adopt a trail or park near a steam or lake or participate in an event like RiverSweep. To adopt visit Denver Parks and Recreation volunteer site, or volunteer at one of The Greenway Foundation and Groundwork Denver's river clean up events.
  • Report any of the following unusual conditions in Denver's lakes and streams by calling 311:
    • A change in color of the water
    • An unusual of foul odor
    • Suds when there has not been recent precipitation
    • Any unusual-looking substance discharging from a storm outlet
    • Illegal dumping activity
    • Unusual discharges from construction sites or industrial sites
    • A large number of dead or dying aquatic animals including fish, crayfish, insects, waterfowl or other animals


  • Adopt a trail or a park
  • Volunteer with Denver Parks and Rec
  • Volunteer at one of The Greenway Foundation’s  events.
  • Check Groundwork Denver’s calendar of volunteer opportunities.
  • Organize a neighborhood stream or lake cleanup by contacting DDPHE.

River Redevelopment Plans

In 2014, the City’s Department of Parks and Recreation began work on an ambitious plan to improve the parks along Denver’s river corridor. Since then, improvements have been made to Lakewood Gulch, at the confluence of Weir Gulch and the South Platte River, Johnson Habitat Park, a stretch of river between Overland Pond and Pasquinel's Landing, Globeville Landing, and Confluence Park.

The city is also working with the U.S. Army Corps of Engineers on a plan to re-envision parts of the South Platte River, Weir Gulch, and Harvard Gulch. More information about that project can be found on the Denver Urban Waterways webpage.

All of the projects include improvements that will benefit water quality in the South Platte River.