DWM Publications > Table of Contents > Chapter Three

THE CLEAN WATER BOOK:
CHOICES FOR WATERSHED PROTECTION

In some areas of the state, the outfall may lead to a stormwater management basin. These basins control the flow of stormwater and can also improve water quality, depending on how they are designed.

In some urban areas of the state, the stormwater and sanitary sewer systems may be combined. Here both stormwater and sewage from households and businesses travel together in the same pipes. Both stormwater and sewage are treated at sewage treatment plants except during heavy rains. During these occasions, both the stormwater and untreated sewage exceed the capacity of the treatment plant and this overflow is directed into local waterways.

In the stream, more erosion of stream banks and scouring of channels will occur. This in turn degrades habitat for plant and animal life that depend on clear water. Sediment in water clogs the gills of fish and blocks light needed for plants. The sediment settles to fill in stream channels, lakes and reservoirs.

In addition to the high flows caused by urbanization, the increased runoff also contains contaminants. These include litter, cigarette butts and other debris from sidewalks, motor oil poured into storm sewers, settled air pollutants from car exhaust as well as pesticides and fertilizers from lawn care. These contaminants reach local waterways quickly after a storm.

Stormwater collection systems or storm sewers typically carry rainwater to an outfall along a local lake, stream or other body of water. In the first rush of water from a rainstorm, much of the debris and other polluting substances that had settled on the land surface and in the stormwater collection system since the last storm will be picked up and carried into the local stream. This can significantly add to water quality problems. It is therefore important to protect all components of the stormwater collection system from sources of pollution. The following should never be dumped down storm drains, road gutters or catch basins: motor oil, pet waste, grass trimmings, leaves, debris and hazardous chemicals of any kind. Anything dumped in our stormwater collection systems will be carried into our streams.

Surface runoff can be decreased and ground water infiltration increased by the following suggestions:

Install gravel trenches along driveways or patios to collect stormwater and filter it into the soil.

Resod bare patches in your lawn as soon as possible to avoid erosion.

Grade all areas away from your house at a slope of 1 %.

Use a grass swale (a low area in the lawn) to move water from one area to another.

Plant shrubs and trees to promote infiltration (see chapter on lawn and garden care).

If you are building a new home or in a position to consider regrading your property, you may want to create a basin, which will hold all runoff and allow it to infiltrate the soil over a longer period of time. This should only be done where drainage is good or infiltration devices are in use. Alternatively, you may be able to create a gently rolling surface or a system of berms and swales to slow run-off. Berms and swales are slight elevations and depressions in the surface that provide channels along which water will flow. If you have a wet area, you may be able to move it to a less used area of the yard (around shrubs or trees, for example) by installing a swale to carry the water across the yard. (Be advised that most activities performed in regulated wetlands require a permit. Contact NJDEP Land Use Regulation for information at (609) 292-0060.) Plant the new wet area with the kind of trees and shrubs that thrive in wet soils.

Wood decks, usually installed for their functional good looks, can serve as a form of porous pavement. Redwood, cedar and treated pine are as durable as most other paving surfaces. Decking allows rainwater to soak into the ground beneath it, and the space between the planks provides ample room for precipitation to drain directly onto the soil surface. As long as minimal air space is maintained between the soil surface and the decking, wood rot can be minimized.

If you are installing a new patio or rebuilding a crumbling sidewalk, you don't need to use the typical slab concrete. Using bricks, interlocking pavers or flat stones (flagstone, bluestone or granite), you can construct an attractive, durable walkway. If placed on well-drained soil or on a sand or gravel bed, these modular pavers allow rainwater infiltration. Avoid using chemicals to control weeds growing in the joints between the pavers; Corsican mint or moss can crowd out weeds and add beauty to the paved area.

Pre-cast concrete lattice pavers also rest on a bed of sand and gravel and allow rain to soak slowly into the ground.

Dutch drains carry water from rain spouts into the soil, where it gradually filters into the ground.

These kinds of paving materials can be used wherever natural soil drainage is good and there are no problems with either bedrock near the surface or seasonal high water table. Significant strides have been made in the last few decades in developing porous asphalt pavement. This material is similar to conventional asphalt in durability, but it contains a much smaller percentage of very fine particles. As a result, the asphalt allows water to soak through into the soil below.

Plants and trees can create "outdoor rooms" where you and your family can work and play. Well-planned landscaping can reduce heating and cooling costs for your house by as much as 30%. New shrubs and trees may attract birds and wildlife. Trees, shrubs and ground cover also require less maintenance than grass. Because trees and shrubs require less fertilizer and fewer herbicides than grass, the chances of polluting streams is minimalized.

Another possibility is landscaping for wildlife. By selecting appropriate plants, landscaping can reduce water pollution and serve wildlife too. Four basic elements will need to be provided for wildlife: food, water, shelter and space. Food can be supplied through vegetation that provides seeds, nuts or berries. Water, if not available nearby as a stream or lake, can be provided as a small pool or pond. Shelter which provides protection from predators or the weather can be vegetation, a pond or even a brush pile. Space needs vary among wildlife but include enough room to reproduce, find food and carry on the different parts of their life cycle. The specifics depend on whether or not your trying to attract a variety of wildlife or certain group, such as butterflies or hummingbirds. For more information, contact, NJDEP Division of Fish, Game and Wildlife, CN 400, Trenton, NJ 08625-0400.

Landscaping your yard reduces the erosive force of rainwater runoff and increases the value of your home. By planting trees, shrubs and ground cover, you encourage excess rainwater to filter slowly into the soil instead of flowing directly into storm drains or nearby streams. Choosing trees and plants that are appropriate for your soil and growing conditions will ensure that you will have a beautiful yard.

For more information on landscaping, see the chapter on Lawn and Garden Care.

Think about the ultimate destination of rainwater in your home and neighborhood. Consider the kinds of pollution that can be picked up by rushing rainwater and carried through the local stormwater collection system into streams and lakes.

Never dump motor oil, grass trimmings, leaves, animal waste or other pollutants into road gutters, storm drains or catch basins.

Landscape your yard to minimize rainwater runoff.

Divert rain from paved surfaces onto grass to permit gradual infiltration.

Preserve the established trees in your neighborhood, which help minimize the damage caused by surface run-off.

Choose the appropriate plants, shrubs and trees for the soil in your yard; don't select plants that need lots of watering (which increases surface run-off).

Consult your local nursery or Rutgers Cooperative Extension for advice on which plants, shrubs and trees will grow well in your yard.