If your new home is like most, the builder did some grading of your lot, removing some or all of the existing vegetation or ground cover. You may have new sod, or you might just have a bare soil yard.
When rain falls on exposed soil, it can wash soil away from the land. This runoff can erode bare ground, wash away valuable topsoil and make landscaping more difficult. It also carries soil, nutrients and other pollutants into streets, gutters and ditches, where it then travels untreated to lakes, rivers, streams or wetlands. Polluted runoff can cause excessive growth of weeds and algae in water bodies and reduce recreational opportunities such as swimming and fishing. Sediment-laden runoff can also clog ponds and wetlands and reduce floodwater retention.
Your homebuilder was required to take steps to keep soil and sediment from leaving your lot. Permanent stabilization such as sod may have been installed on part or all of your property. If not, you can help protect the environment by ensuring that soil and sediment are not washed off your property and that grass or other ground cover become well established.
When construction on your home is complete, verify that your builder installed temporary stabilization measures to minimize erosion and prevent sediment-laden runoff from discharging into streets, gutters, ditches, streams, lakes and wetlands. Silt fence or other sediment control should be in place on the down slope perimeter, and near curb and gutters, ditches, streams, lakes and wetlands. Mulch or similar material must cover exposed soil. Soil piles must also be stabilized.
As a homeowner, you are responsible for inspecting and maintaining temporary stabilization measures until permanent ground cover is established on your yard.
Commonly used temporary stabilization methods include:
Temporary vegetation includes annual grasses that sprout quickly such as annual rye, oats and winter wheat. These grow quickly with little care and can protect the soil from rain, slow runoff, and act as a filter. They will not provide permanent cover. You may need to fertilize, water or reseed to ensure the vegetative cover is maintained until permanent cover is installed.
Mulching (straw, wood chips, wood fiber blanket, and so on) provides temporary cover to protect the soil from rain. Mulching may be the only option during the winter when seeding or sodding is not possible. Mulch must stay in place to be effective. Netting, stakes or chemical binders are used to anchor some types of mulch. Be sure to reinstall washed-out mulch and anchor if necessary until permanent cover is established.
Silt fences are curtains of permeable fabric erected on stakes to restrict run off. The silt fence slows runoff and allows it to puddle or pond, so soil and sediment can settle out before water leaves a site. Other sediment control devices include berms, biologs, and more. Proper installation and maintenance of sediment control devices is essential for their performance. Reinstall or replace ripped, collapsed, undermined or decomposed fencing. Remove sediment if deposits reach 1/3 of the silt fence height. Remove silt fences and other sediment control devices only after permanent stabilization is established.
Downspout extenders may be used to protect temporarily stabilized areas from roof runoff. Extenders can direct water from your roof gutters to paved or grassed areas. Be aware that direct discharge to storm sewers (as in the photo) may not be allowed in your area. Be sure to check with your local authorities. Check extenders regularly to insure proper performance. Remove extenders following permanent stabilization.
Establish permanent vegetation or ground cover as soon as possible. Mulch, silt fences, downspout extenders, or other temporary stabilization measures can be removed following permanent stabilization.
Please consider the following as you make your landscaping decisions:
Finally, you can also help area lakes and streams for as long as you own your home. Stormwater runoff does not go to a wastewater treatment plant. It flows directly into our lakes and streams. There are many ways you can reduce polluted runoff:
For more information on stabilization measures, contact your local building inspector or Soil and Water Conservation District Office.
You can also visit Minnesota Pollution Control Agency Stormwater website or call the Stormwater Program at 651-757-2119 or toll-free at 800-657-3804.