Watersheds 101

A watershed is an area of land that drains or sheds water into a specific waterbody, such as a lake, river, or stream. Every body of water has a watershed.

We live in the La Crosse Pine Watershed which covers an area of approximately 1,622 square miles in western Wisconsin and eastern Minnesota.

Mississippi Winona Watershed

Runoff Pollution 101

What is runoff?  When rain falls or snow melts, that water flows over a surface such as an area of land in rural areas, or hard surfaces in urban areas.

What is hard surface? Hard, or impervious, surfaces that do not allow water to pass through them, can include roofs of buildings, roads, driveways, cars, sidewalks, parking lots, and more.

What is runoff pollution? When runoff travels over hard surfaces it picks up sediments and nutrients including: soil particles, lawn clippings, leaves, pesticides, pet wastes, and other pollutants. In urban areas, these pollutants flow untreated into storm drains, which run directly into local waterways.


Sediments & Nutrients

Sediments are soil particles and other debris that gets washed away from farmland, stream banks, construction sites, and urban neighborhoods.

Nutrients, including phosphorus and nitrogen, come from sediments, manure and pet wastes, leaves, grass clippings, poor septic systems, and lawn or crop fertilizers.

  • Poor Fishing - Sediments fill in waterways, making the water shallower and warmer. Cold water fish, like trout, are replaced with warm water fish, like carp.
  • Consumption Advisories - Toxic sediments are eaten by fish and waterfowl. These toxins can build up, causing illness, birth defects, and death in the fish and waterfowl, as well as humans who eat them.
  • Muddy Waters - Sediments cloud the water, making it difficult for aquatic organisms to see, feed, breathe, and reproduce. Visibility also increases the chance of boats hitting underwater hazards and makes swimming less desirable.
  • Beach Closings - Phosphorus over fertilizes waterways causing fecal contamination and excessive algae growth. Both are harmful to aquatic and human life.
  • Habitat Loss - Excess algae block sunlight, which reduces the plant life that is essential food and habitat for fish and waterfowl.
  • Fish Kills - When manure, pet waste, leaves, and grass clippings enter waterways, their decompolition process reduces oxygen levels and releases ammonia, both deadly for fish and other aquatic life.

Municipal Stormwater Management

Our local governments make plans and systematic investments to manage stormwater. It’s required. It’s important. And it requires persistent effort to maintain hundreds of miles of ditches and pipes, clean up thousands of tons of debris from street, and ensure all new construction minimizes runoff. Read here about some things our local county, cities, towns, and villages do to manage stormwater runoff for everyone!

Green Infrastructure

Local governments are making strategic, green-infrastructure investments to manage stormwater. Green infrastructure provides cleaner air and water as well as significant value for the community with flood protection, diverse habitat, and beautiful green spaces.

public parking lot
Water-friendly landscape at Municipal Buildings 
map thunderbird hills
Neighborhood Project Implementation 
rock garden at house
Stormwater Utility Credits for Property Owners 
BMPs at Municipal Owned Properties 
BMPs at Municipal Owned Properties 
Permitting requirements 
Permitting Requirements 
Retention Basins in Municipal Parks
Retention Basins in Municipal Parks

Maintenance and Pollution Prevention

Optimal stormwater management takes the use of both existing gray infrastructure and green infrastructure. Gray infrastructure is traditional stormwater infrastructure in the built environment such as gutters, drains, pipes, and retention basins.

This infrastructure remains important in order to treat of high volumes of runoff in compact areas and provides a source or pollution prevention as long as it is properly maintained.

Storm Drain Cleaning & Repairs
Storm Drain Cleaning & Repairs
street sweeper
Street Sweeping
ditch restoration
Ditch Restoration
Stormwater Treatment Areas
Stormwater Treatment Areas
Smart Salting
Smart Salting
sewer drain
Illicit Spills and Discharges

Our local governments make plans and systematic investments to manage stormwater. It’s important. It requires persistent effort to develop and manage best practices, maintain hundreds of miles of ditches and pipes, clean up thousands of tons of debris and sediment, and ensure permitting requirements are in place and being implemented. 

Learn more about how local municipalities are managing stormwater. 

Reduce Runoff on Your Property

Help stop polluted runoff. Working together, individuals and communities can take steps to clean up our local waterways and restore their natural beatty. When individual property owners do their part to prevent runoff, everyone benefits.

Car Care

Go to a car wash

When you clean a car in the driveway or street, sand, salt, emissions and detergent flow with the water into the street drain and then to the river, untreated. At a car wash, water goes to the wastewater treatment plant where oil, grease, detergent, sand and grime are removed. If you must wash your car at home wash it on your lawn, use biodegradable soap, and dispose of leftover water in toilet or sink.

teen washing their car
oil from car on ground

Maintain your vehicle

We’ve all seen an oily sheen on water in streets and parking lots. It comes from small leaks, accumulated residue and fuel overfills from our cars. When a vehicle is maintained, fewer leaks spill onto streets and highways and fewer contaminants enter streams. So when you’re tempted to put off repairs or the six-month maintenance check, think again.

Walk, ride your bike or take the bus

We all know air quality is affected by vehicle emissions. But did you know emissions also affect water quality? Tiny particles emitted from tail pipes settle on roadways, wash into storm sewer systems, then flow into rivers and streams.

inside bus with people

Lawn Care

Use grass clippings and leaves

Learn how to compost. Turn clippings into rich organic matter that makes everything in your yard grow better. Composting is a practical climate change mitigation and adaptation strategy that can be adopted at the individual level. As a climate action strategy, composting has the potential to divert a large portion of organic materials from landfills, while returning these nutrients to the soil.

person holding soil

For a healthy lawn, enrich the soil instead of using chemicals and weed killers

Test the soil to find out if your lawn needs more nutrients. If soil conditions are poor, enhance the lawn by mulching. A healthy, mulched lawn outcompetes weeds for light, nutrients, and water. In La Crosse County, soil testing is available through the UW Extension.

Keep leaves, grass, trash and other waste out of the street

Litter and toxic substances are obviously harmful but soil, sand, leaves and grass clippings also damage streams. They cloud water, reduce depth, alter habitat and prevent spawning for some species. So remember—everything in the street picks up vehicle fluids and exhaust particles as it flows the storm sewer system, where it goes directly to the river.

In some communities, placing leaves or yard waste into the street is a violation of municipal code.

water collecting in street
plants along water

Manage waterfront with a buffer strip of dense, native vegetation

Native plantings filter water and keep pollutants out of streams. They protect the shoreline during high water and storms, create habitat for birds and other native species, and need almost no care once established. Start by simply not mowing near the stream.


brick patio

Minimize hard surfaces

Concrete, blacktop and other hard surfaces rush large amounts of water off your property to storm sewers and ditches. In fact, 75% more rain water sinks into the ground in a natural area versus a developed area. Permeable pavement like gravel or bricks allows water to sink into the ground.

Build a rain garden

Rain gardens are slight depressions in the yard that act as receiving areas for rainwater flowing from downspouts, roof, street or driveway. They capture water and soak it up before it picks up oil, grease, fertilizer, pet waste or other contaminants on its way to the storm drain. Usually they’re filled with native plants, easy to build, and make a great neighborhood project. More information can be found in the Rain Garden and Native Plants sections.

house with a rain garden in front yard

Redirect Downspouts

Redirect downspouts that drain to your driveway or sidewalk onto the grass, into a rain garden, or install a rain barrel for future use. More information can be found in the Rain Barrel section.


pet waste pick up sign

Pick up after your pets

Pet waste is not only unpleasant on your yard or sidewalk, but carries bacteria that cause beach closings in summer. Carry small plastic bags when you walk your dog, and do not throw pet waste in the street drain. At home, pick up pet waste often to keep it from filtering into groundwater.

Parking Lots

parking lot island with vegetation

Change parking lots to reduce runoff

Direct water to bioretention basins, rain gardens and native plantings. Add trees and islands of native plants that collect water in and around the lot. Remove excessive asphalt to minimize the amount of runoff. Where pavement is needed, replace with a porous product if possible. On tight urban sites consider underground french drains, holding areas and curb cuts. You’ll see better organized traffic, less heat generation, community attention and most likely, lower costs.

Snow Removal

salt eroding pavement

Make a Plan for Smart Salting

Before winter arrives, develop a cold weather maintenance plan, and train yourself, or your crew accordingly. Store snow in a location where it’s not going to melt and flow through salt or sand piles or any natural areas. Protect sand and/or salt piles from rain or snow.

Use calcium magnesium acetate (CMA) rather than salt. Just one teaspoon of salt can contaminate five gallons of water FOR-EV-ER. And remember, deicers aren’t for melting away every bit of snow and ice. Use just enough to break ice away from the pavement, then shovel away the slush.

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