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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

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February 2003

On the home front

Rounding up runoff in your yard.

Natasha Kassulke


Contents
Yard waste
Fertilizer | Car care
Salting and sanding
Pet waste | Rain barrels
Concrete wash
Gutters and other building supplies
On the water's edge

Much of the 92 million acres of developed land in the United States belongs to homeowners, and some conservationists consider this area fertile ground for conservation.

One project, "Backyard Conservation," joins the Natural Resources Conservation Service (NRCS), National Association of Conservation Districts (NACD), and the Wildlife Habitat Council (WHC) in asking homeowners to help make one million backyards "friendlier places for nature."

The project teaches conservation practices like terracing, tree planting, composting and mulching.

Whether your backyard is a 500-acre farm or a flower box on your balcony apartment, you don't have to do much or spend a lot to curb storm water and make your yard more inviting for birds and insects, explains Pearlie Reed, NRCS chief.

Ken Potter, a University of Wisconsin-Madison professor in civil and environmental engineering, is developing ways homeowners can estimate storm water runoff from their property. The audit includes estimating runoff from roofs, assessing options to divert downspouts and taking soil tests. Soil conditions are key; some soils infiltrate better than others.

"There is a lot of room for creativity in this area," Potter says. "We have to get people to understand that storm water is about using water locally and protecting lakes. It's not just about taking the storm water away and maintaining pipes. It's about bringing storm water control to a personal level."

Yard waste

In 1993, Wisconsin law banned yard waste from landfills, but that didn't stop bushes from growing or leaves from falling. If yard waste piles on streets and curbs for days awaiting pickup, it sends unwanted nutrients to lakes and clogs storm sewers.

You can help by avoiding piling leaves in the street and scheduling raking as close to collection time as possible. Reuse yard waste. Yard trimmings can be chopped and mulched. Let grass clippings dry and in a few days they will filter to the soil and decompose. Lawn care manuals recommend a minimum lawn height of three inches. This supports longer root growth and protects against draught and blade damage.

Composting leaves and other yard waste will prevent organic matter from clogging storm drains. © Roger Bannerman
Composting leaves and other yard waste will prevent organic matter from clogging storm drains.

© Roger Bannerman

Mulches add organic matter to soil, keep weeds down, retain moisture in gardens and protect roses and other plants in the winter. After seeding bare soil, cover it with mulch to minimize erosion. Some people use mulching mowers, bagging mowers and power chippers to reduce yard waste.

Composting may be affordable since you don't need special equipment to get started. Piled yard debris will eventually compost, but this "cold composting" may not decompose weed seeds and disease-causing organisms may not be destroyed.

Brochures describe how to start a hot compost pile by keeping the pile the right size, maintaining the right mix of nitrogen and phosphorus wastes, adding moisture, keeping the pile airy, turning the pile and letting it cook.

Compost bins are available in many styles. Some resemble garbage cans; compost is dumped in the top and finished compost is scooped out the bottom. Other bins may be rolled to mix and aerate the compost. Or build your own bin by rolling wire mesh, which allows for aeration from all sides.

Finished compost is crumbly to the touch and pleasant smelling.

Fertilizer

Fertilize conservatively and carefully.

Potter recommends testing the soil through UW-Extension or buying a test kit at a gardening center to determine if fertilizers are needed. Extension research suggests lawn fertilizing should begin in early October, not May. Spring applications promote more top leaf growth than root growth and these shallow root systems may not survive a drought or harsh winter. Fall fertilizing promotes deep and healthy root systems.

Also keep fertilizers off sidewalks/driveways and use the proper amount for the space. If you use weed-and-feed fertilizers, and granules spill onto a paved area, sweep them back into the lawn. Do not spray liquid fertilizers or herbicides on a windy day when they may drift onto pavement or across your property line.

When cleaning fertilizer application equipment, wash it on grassy areas and apply rinse water to the lawn.

Try to buy phosphorus-free fertilizer. And make sure your lawn needs watering before turning on the hose. Sprinkler runoff can make a natural problem worse. Most lawns are watered during hot weather and low water conditions when streams and lakes are primed for growing algae and weeds.

Car care

Car washing is a popular weekend activity. But what happens when the rinse water leaves the driveway? The detergent joins antifreeze, oil, grease and bits of tires, brakes and rust left by cars on the streets and is carried into storm sewers.

Keep your car tuned-up. Smooth running cars burn less fuel and cause less pollution. Spots on the driveway are a clue that your car is leaking. Use cat litter to soak up the spill. Then sweep up the litter and dispose of it in a sealed trash bag.

When oil, antifreeze, brake fluid and transmission or power steering fluid need to be changed, collect the old fluids in leak-proof containers and take them to a service station for recycling. A gallon of used oil can contaminate up to one million gallons of drinking water.

Return or recycle batteries. Old batteries may leak acid. Neutralize spilled acid with baking soda or lime.

If you wash your car at home, you can clean it on the lawn where the soil will help filter out pollutants. But be aware that the weight of the car compacts the lawn and can lead to runoff. Consider using commercial car washes with spray booths to control runoff.

Salting and sanding

Salt may get rid of snow and ice on your sidewalk and driveway, but it also can kill trees and grass, cause fish kills, and corrode bridges and underground cables. Some studies have shown increases in chloride levels in our groundwater. Limit salt use on sidewalks and driveways and ask your city to discontinue salt use on residential streets. If you need to use sand for traction, keep an eye on it. After the snow melts, sweep up the sand and keep it out of storm sewers.

Pet waste

Pet waste on the sidewalk or lawn can lead to disease and may wash into lakes and streams.

Check local ordinances for proper pet waste disposal. Options may include flushing the waste down the toilet, burying it – dig a hole at least five inches deep and away from vegetable gardens and surface waters – and, if local ordinance allows, disposing of it in an underground pet waste digester that works like a small septic tank.

Rain barrels

Rain barrels can be a practical storm water storage option. Collected rain water is better for plants because it's not chlorinated and mildly acidic, which helps plants take up important minerals from the soil. Some people recycle rain barrel captured water for toilet use.

"Rain barrels on all the downspouts could control about 10 percent of the annual runoff from the roof," says Roger Bannerman, a DNR nonpoint source monitoring researcher.

Rain barrel costs also vary from $79 in home and garden catalogs to $100 for a 200-gallon galvanized stock tank at a feed store. Put a screen on the barrel to prevent mosquito breeding.

Concrete wash

One often-overlooked storm water problem is concrete wash water from construction projects such as sidewalk installations. Water used to clean the concrete shoots becomes acidic, kills grass and often winds up in storm sewers. Collect concrete wash in a barrel and allow the water to evaporate off or dispose of it in an area where soil can act as a filter.

Gutters and other building supplies

Building materials, from gutters to shingles, contribute to storm water based on their composition and function.

Stormwater from residential and commercial areas has a high probability of exceeding water quality standards for copper, zinc, organics and bacteria.

Zinc also is toxic to aquatic life. Roofs and gutters can be a significant source of zinc. Galvanized metal rooftops, gutters and downspouts account for 61 percent of zinc in industrial areas where downspouts discharge onto pavement or directly into storm sewers.

If you attend home shows or shop around, you can find gutters made of aluminum, vinyl and other materials. One product replaces gutters with metal slats that look like inverted Venetian blinds. These scatter water droplets over a wider area, reducing its velocity and scouring power.

Redirecting downspouts to lawn areas and away from pavement also reduces the pollutants storm water carries. In Milwaukee, officials have tried a downspout disconnection program in one neighborhood. The city reimburses homeowners $50 per downspout with a $100 limit per home in an effort to reduce the amount of rainwater entering the city's sewage system.

On the water's edge

Sediment and silt in storm water runoff can bury gravel and beds necessary for spawning fish, mayflies and frogs. A lawn mowed to the shoreline edge sends fertilizers, pet waste and lawn clippings into the water where they fuel algae blooms.

According to DNR research, lawns can cause seven times the amount of phosphorus and 18 times the amount of sediment to lakes as flow from properties with natural shorelines.

For those living on the waterfront, there are ways to manage lawns and minimize runoff during construction and chores. Growing buffer strips of dense and natural vegetation along the water's edge will filter pollutants and stabilize the shoreline.

More and more, waterfront residents are switching from golf course-style manicured lawns to no-mow zones of native sedges and grasses, shrubs, and ground cover. Besides curbing runoff and giving wildlife home, this vegetation requires less maintenance, which frees up more time to go fishing.

Buffer strip width depends on the terrain. Research suggests that on a gentle slope, a 35-foot strip of natural vegetation between the water edge and mowed lawn area is needed for some shoreline wildlife. On steeper grades, even more vegetation may be needed to stabilize soils and reduce the need for retaining walls and other erosion prevention.

Shoreland management is a partnership between individuals, state and local government. Each county has shoreland zoning ordinances that regulate development near navigable lakes and streams, in compliance with statewide minimum standards. To learn which shoreline alterations are prohibited or require a permit, call your local DNR office or county zoning office.

Natasha Kassulke is the associate editor of Wisconsin Natural Resources magazine.