How You Can Help Keep Our Water Clean

Clean water is essential to the health of our communities, environment, and economy—and protecting it starts with understanding how stormwater works. Here you can learn about stormwater, why water quality matters in Douglas County and how everyday activities can affect our waterways. You’ll find information on common sources of pollution, simple definitions of key terms and links to more detailed guidance tailored for residents, businesses and partner organizations. Whether you’re just getting started or looking to take the next step, this is a great place to learn how you can help keep our water clean.

What is stormwater? How is stormwater different? Stormwater Pollution Stormwater Glossary of Terms How Residents Can Help Keep Our Water Clean How Businesses Can Help Keep Our Water Clean Resources for Our Partners

What is stormwater?

Stormwater runoff occurs when rain or snowmelt flows over the ground on its way to storm drains, drainage ways, creeks and lakes.

Why does it matter?

Stormwater can pick up debris, chemicals, dirt, pet wastes and other pollutants and deposit them in water bodies we use for swimming, fishing and drinking. Runoff from a rainstorm or snowmelt is not treated at a wastewater treatment facility, so we all have a responsibility to keep it clean.

How is stormwater different from wastewater?

For most people in Douglas County, there are two sewer systems serving your home, business, neighborhood and community:

The sanitary sewer system carries wastewater (think bathrooms, kitchen drains and laundry) from homes, schools, businesses and other buildings to a water treatment facility (pictured). Once there, harmful elements are removed before the water is discharged.
The stormwater system carries rain, snow melt and other runoff away from roads, parking lots and buildings (ie. gutters) through a series of pipes and detention basins before discharging it into creeks, rivers and lakes untreated.

Stormwater pollution

Since stormwater flows untreated back into creeks, rivers and lakes, it can get polluted. Polluted runoff is one of the main causes of water pollution in the United States. Stopping pollution at the source is vital to keeping our waterways beautiful and healthy.

Most Common Pollutants in Douglas County

1. Pet Waste

Stormwater can pick up pet waste that pet owners leave on the ground and deposit it directly or via a storm sewer system into nearby creeks, rivers and lakes. Pet waste in waterbodies can make people and animals sick, promote weed and algae growth, and damage the health of the ecosystem in and around the water. Pet waste is a leading source of nutrient and bacteria pollution in urban streams and waterways.

2. Fertilizers & Manure

Fertilizers and animal manure help plants grow, but when they’re overused or mismanaged, they can wash into creeks, rivers and lakes. This runoff carries excess nitrogen and phosphorus that fuel algae blooms, deplete oxygen in the water and harm fish and other aquatic life. Some algae, like blue-green algae, can even produce toxins dangerous to pets, livestock and people.

Nutrients and manure can also contaminate drinking water with nitrates or harmful bacteria. Because nitrates move easily through soil, unused fertilizer or poorly handled manure can seep into groundwater. Runoff can also carry pathogens that pose health risks for humans and animals.

By managing nutrients wisely, we protect local waterways, safeguard drinking water and keep Douglas County healthy for everyone.

3. Trash

Litter that ends up in our creeks, rivers and lakes, sometimes called aquatic trash, comes mostly from everyday activities on land. A wrapper dropped on the sidewalk, an overfilled trash bin or a cigarette butt tossed on the ground can easily be carried by wind or rain into storm drains and directly into local waterways. Once there, this pollution harms wildlife, damages habitats and reduces the beauty and safety of the places we love.

Plastic trash is especially harmful because it never fully breaks down. Instead, it fragments into tiny “microplastics” that can be eaten by fish, birds and other animals—even making its way up the food chain. Aquatic trash also affects human communities. It’s expensive to clean up, can negatively impact our recreation areas and creates health and safety risks when it accumulates.

Together, simple daily actions can keep trash out of our waterways and protect Douglas County’s and Colorado’s natural beauty for generations to come.

Stormwater Glossary of Terms

Inlet

An inlet is an opening, often with a grate or curb, that allows stormwater from streets, parking lots or yards to enter the storm drainage system and be carried away through underground pipes toward creeks, rivers, lakes or detention areas. Inlets are key entry points where runoff begins its journey through the stormwater network.

Municipal Separate Storm Sewer System (MS4)

A Municipal Separate Storm Sewer System (MS4) is a publicly owned network of storm drains, pipes, curbs, gutters, ditches and other conveyances designed to collect and move stormwater to local water bodies without treatment. MS4s are operated by cities, counties and other public entities and are regulated under the National Pollutant Discharge Elimination System to reduce pollutants in stormwater runoff.

Nutrient Pollution

While it may sound odd that creeks, rivers and lakes can be polluted with nutrients, it’s like having too much of a good thing. Nitrogen and phosphorus are nutrients that are natural parts of aquatic ecosystems and support the growth of algae and other aquatic plants, which provide food and habitat for fish, shellfish and smaller organisms that live in water.

Too much nitrogen and phosphorus in the water causes algae and algae-like bacteria to grow faster than ecosystems can handle, forming algal blooms. Significant increases in algae harm water quality, food resources and habitats, and decrease the oxygen that fish and other aquatic life need to survive. Algal blooms can severely reduce or eliminate oxygen in the water, leading to fish illnesses or deaths, often in large numbers.

Nutrient contamination in ground water – which millions of people in the United States use as their drinking water source – can be harmful, even at low levels. Infants are vulnerable to a nitrogen-based compound called nitrates in drinking water. Excess nitrogen in the atmosphere can produce pollutants such as ammonia and ozone, which can impair our ability to breathe, limit visibility and alter plant growth. When excess nitrogen comes back to earth from the atmosphere, it can harm the health of forests, soils and waterways.

Stormwater

Stormwater is the rainwater and snowmelt that flows over surfaces like rooftops, streets, yards and parking lots rather than soaking into the ground. As it travels, stormwater can pick up sediment, chemicals, trash and other pollutants, carrying them into storm drains and directly into creeks, rivers and lakes without treatment.

Watershed

A watershed is all the land, surface water and groundwater that drains to a common point—such as a creek, river, lake or reservoir. Water falling anywhere within a watershed eventually flows downhill to that shared water body, so actions taken anywhere in the watershed can affect water quality downstream.

The Cooperative for Local Environmental Awareness & Responsibility (CLEAR) is a regional partnership dedicated to safeguarding Douglas County’s creeks, rivers and lakes through effective stormwater management. By uniting local governments, districts and community partners, CLEAR helps ensure clean water, healthy habitats and compliance with state water quality standards. CLEAR connects the community with the resources and knowledge needed to protect water quality for generations to come. Learn more about CLEAR’s mission and impact.