How Can You Prevent Stormwater Pollution?

In Las Vegas’ arid climate, clean water is the most valuable resource. Polluted stormwater runoff degrades the water quality of Lake Mead – the Valley’s primary source of drinking water. To preserve our water for future generations, it is important to understand where it comes from and what impacts it.

Everyone plays an active part of preserving water quality! Ensure that only rain goes down the storm drain by limiting fertilizer application, pick up pet waste, manage trash, and properly dispose of paint, vehicle oil, and chemicals. If you observe abuse of any of the mentioned behaviors, report it to the Water Quality Team, using either the Water Quality Hotline, (702) 668-8674, or complete the Report a Violation online form.


Simple changes to common behaviors and learning to recognize and report pollution problems can help keep our environment as clean and health as possible. Your everyday activities can have significant impact on stormwater runoff and the environment! Follow the tips listed below and help prevent stormwater pollution:

In Your Home/Business

• Go natural! Clean with least toxic cleaners.
• Dispose of hazardous waste properly. Never pour paint, coolant, motor oil, cleaners or solvents outdoors or down storm drains.
• Store maintenance and cleaning products inside or under cover.

In Your Yard

• Don’t overwater.
• Select native plants that are drought tolerant.
• Use pesticides and herbicides sparingly and in accordance with manufacturer’s instructions; never apply before or immediately after a storm.
• Compost yard and garden waste.
• Sweep yard clippings, leaves, litter, and debris to keep them out street gutters and storm drains.
• Control loose sediment to prevent excessive sediment from washing into storm drains.
• Pick up pet waste and dispose of in trash. 
• Properly dispose of pool water, do not drain your pool into the street.

In Your Car

• Wash your vehicle a commercial car wash or direct wash water into landscaped areas.
• Repair vehicle leaks; cover spilled fluids with kitty litter, then sweep into household waste.
• Recycle used motor oil and coolant.

Residue left behind from an illicit discharge that was improperly disposed of in a residential stormwater conveyance.	Tree cuttings that were improperly disposed of in a stormwater channel behind residential development.	Oil leaking from a residential vehicle flowed into the stormwater conveyance.

Wonderful World of Water

What is the Water Cycle?

The water cycle describes the movement and recycling of water on, in, and above the Earth. Earth’s water is always in motion and is changing states, from liquid to vapor to solid (ice) and back again. The water cycle has been recycling the same water for billions of years through evaporation, evapotranspiration, condensation, and precipitation.

• Evaporation occurs when heat from the sun causes water on Earth’s surface to heat up and turn into water vapor. It’s the same thing that happens when water is boiled on the stove. As water evaporates turns into steam (vapor) that rises above the cooking pot.
• Plants constantly absorb water and when it’s hot, the leaves release water vapor during a process called evapotranspiration.
• When the warm water vapor rises into the cold atmosphere, it cools off and turns into tiny water droplets that eventually forms clouds. The changing of warm water vapor into cool water droplets is called condensation.
• Clouds are made of billions of tiny water droplets. Clouds take in more and more water droplets until they become saturated and cannot hold anymore, and the water droplets fall to Earth as precipitation (rain and snow).
• In cold climates, precipitation builds up as snow, ice and glaciers.
• In warmer climates, rainfall flows downhill as runoff, refilling lakes, rivers, and the ocean. Some rain soaks into the ground and becomes groundwater. Groundwater close to the soil surface is absorbed by plants, while deeper groundwater slowly flows into rivers, lakes, and oceans.
• When precipitation stops and the sun comes back out, the streams, rivers, lakes and oceans heat up and water begins to evaporate, starting the cycle over again.

What is a Watershed?

• A watershed is an area of land that drains to the same water body, such as a lake or river. Local topography determines where and how the water flows, while mountains and ridges determine the watershed boundary.
• For an easy analogy, imagine turning an open umbrella upside down in the rain. Rain that falls anywhere within the umbrella’s surface would go to the bottom at the center of the umbrella. Any rain that didn’t hit the umbrella would fall to the ground. The umbrella is like a watershed; it collects everything that falls into it.
• We live in the Las Vegas Valley Watershed. When it rains in the Valley, some rain seeps into the soil and is stored in underground bodies of water, called aquifers. Though desert soils are covered in a hard crust that does not allow water to soak into the ground quickly, some of the water is soaked up by plants. Any water that is not stored in plants or in the ground becomes stormwater runoff. Runoff enters storm drains and flows into Lake Mead through the Las Vegas Wash.
• No matter where you live, work, or play you are within a watershed. Watersheds are important habitats for people, animals, and plants because we all depend on watersheds for the water we use. Remember, from your backyard to Lake Mead, what occurs outdoors affects the water quality downstream!

Desert Wetlands

A wetland is an area of land that is covered by water all or part of the year. Wetlands are an especially important part of the watershed.

Water flowing into the Las Vegas Wash is a combination of highly treated wastewater effluent, shallow groundwater, urban runoff and stormwater runoff. Wetlands vegetation are known to naturally filter out and reduce harmful residues such as fertilizers, oil, and other pollutants that originate from urban activities. As the population of Las Vegas continues to rise, the Wash continues to receive more runoff. Wetlands along the Las Vegas Wash help improve water quality before it reaches Lake Mead.