Minnesota, land of 10,000 lakes, birthplace of the Mississippi and many other rivers – all of which are fed by the dozens of overlapping watersheds in our communities.
We all live in a watershed, and we all contribute to the health of the lakes, rivers and groundwater in our watershed and beyond. A watershed is the area across or under which water flows on its way to lakes, rivers, streams and groundwater. Any area of land is made up of overlapping basins. Water flows to the lowest point in each of these basins – usually a lake, stream, pond or river. This basin is a watershed, and can come in many different shapes and sizes. The Mississippi River watershed, for example, is composed of hundreds of smaller watersheds. Waters from over thirty different states flow into the Mississippi. The waters of Minnesota flow into three major watersheds: north to Hudson Bay via the Red River; east to the Atlantic Ocean via the Great Lakes Basin and St. Lawrence Seaway; and south to the Gulf of Mexico via the Mississippi River. Minneapolis and St. Paul, of course, contribute to the Mississippi River watershed.
Many years ago, the Twin Cities area was composed of oak savannah, broadleaf forests, tallgrass prairie, and marshlands – nature’s water treatment plants. With development, however, much of the land has been covered by structures, concrete, asphalt and agricultural tiling. All of these modifications prevent rainwater from being absorbed into the ground. Instead of filtering through the soil or marsh plants, water flows over these surfaces and into storm drains, absorbing pollutants along the way and depositing them into lakes, rivers and streams. In our area, this means that oil spilled in your driveway will eventually wash directly into the Mississippi.
By the time the Mississippi River reaches the Twin Cities, its waters are already polluted. Where the river reaches the Gulf of Mexico, pollutants carried by its waters cause a “dead zone” seven thousand square miles wide during the summer months. The dead zone is an area of hypoxia, where oxygen levels in the water are low, and little plant or animal life can grow there. Scientists believe that hypoxia in the Gulf is caused by excessive nutrients carried in the rivers’ waters. Overabundant nutrients cause excessive growth of algae, which chokes out sunlight and decreases the amount of oxygen in the water, making it virtually impossible for fish and other aquatic life to live in the area. Due also in part to over-fishing, this dead zone has doubled in size since 1993.
The major sources of pollution in the Mississippi River and other watersheds are urban runoff and agricultural and lawn runoff. Primary pollutants include : phosphates from industrial and home detergents; excessive nitrogen and phosphorus from agriculture and lawn fertilizers; petroleum products from industrial spills, road runoff, improper disposal and recreational boating; pesticides and herbicides from agriculture and landscaping; sediment from erosion; and trash and debris from dumping, storm drains and flooding.
Although Minnesotans enjoy only a few snow-free months, our yards contribute to local water quality all year round. Every time rain falls or snow melts, water winds its way off the roofs and down the sidewalks, through the yards and streets, down storm drains and then directly into the nearest body of water.
|What You Can Do
Clean Up After Yourself!
Lawn Clippings and Leaves. You can always leave your clippings on your yard, but leaves and lawn clippings left on the sidewalk or driveway are easily swept away by water and provide excess nutrients to the nearest lake, stream or river.
Pet Waste. Always carry a bag. Use it. Enough said.
Sand and Salt. After the snow piles have melted, sweep up extra sand and salt. Excess sand can fill in lakes and streams, cover up habitat for aquatic life and carry pollution. Salt is a major contributor of chlorides to our waterways.
Chemicals. When working with chemicals be sure to clean up spills and dispose of used oil, paint, or other chemicals at your local household hazardous waste collection site. Try using natural options for any pesticide or herbicide needs. (See: Integrated Pest Management).
Car Washing. Wash your car on your lawn using a no-phosphorous soap. This keeps soapy water out of the storm drain, and can double as a drink for your lawn! If that’s not an option, take it to a commercial car wash where water is treated before it re-enters local waterways.
Re-Direct Downspouts. Make sure downspouts from your roof are not only directed away from your foundation, but onto your lawn and not your driveway or sidewalk. You can collect the water from your downspouts in rain barrels to be re-used around your yard.
Create a Rainwater Garden. A rainwater garden is a depression in the soil filled with water-loving plants. The depression is designed to collect water from your roof and walkways. Plants absorb and filter the water before it enters local waterways. Some watershed districts offer subsidies to homeowners who make these kinds of improvements.
As you look forward to another six months of bare feet, blooming plants and backyard barbecues, take a few minutes to sweep your sidewalk free of sand and grass clipping and get your soil tested. If we all took care of a few of these items, we could have a great cumulative effect on our local water quality.
Recipes for Clean Water: A Homeowner’s Stormwater Survival Guide, William Boudreau, 1999
Lakescaping for Wildlife and Water Quality, Carrol L. Henderson, Carolyn J. Dinder, Fred Rozumalski, 1999
46 E. 4th St.
St. Paul, MN 651-222-2193
University of Minnesota Extension Water Quality Program
173 McNeal Hall
1985 Buford Ave.
St. Paul, MN 612-624-9282