Landscaping Designs and Practices
Landscaping design and practices affect both the quantity and quality of storm water runoff. Water quantity may be reduced and water quality preserved using several design strategies:

Preserve natural vegetation

• Minimize impervious surfaces
• Use vegetative swales and natural storage systems for runoff
• Allow infiltration of runoff

Compacted soils, thatch build-up, and over-watering increase the volume of runoff, while fertilizers and pesticides impair water quality. Good soil preparation and low-maintenance plantings reduce the need for irrigation, fertilizers, and pesticides. In addition top protecting water quality, minimizing the use of water and chemicals makes good economic sense. For example, one Michigan company reduced the annual cost of maintaining its landscape from $2,500 an acre to $500 an acre by replacing its traditional landscape with native plantings.

Native plants and their importance
The definition of native plants has been constantly debated, but one might think of them as the plants that were here when Christopher Columbus discovered America. More specifically, they are plants that have adapted themselves to local soil, rainfall, and temperature conditions and have developed natural defenses toward many types of insects and disease. With these characteristics, native plants grow without the need for fertilizer and are more resistant to insects and disease than imported species.

Lawn use
Soil permeability is important in maintaining water quality. Contrary to popular belief, some lawns approach the imperviousness of concrete as the soil underneath is subject to repeated foot traffic. In addition, the build-up of thatch and the root system of grass form a mat that does not allow water to penetrate easily. Lawns also require fertilizer, pesticides, mowing, and watering. These needs can be reduced by replacing turf grass with lower maintenance plantings or by expanding flowerbeds. Expanding flowerbeds increases permeable area and allows for the planting of native perennials that require little additional water or maintenance. Of course, it is not realistic to replace all grass with low maintenance plantings. Look for opportunities where it is best to use low maintenance plants to fulfill a particular function.

Eroded soil is a leading water pollutant in the middle Huron River. Also, uncontrolled sediment can clog storm water management systems, leading to flooding and higher maintenance costs. Soil erosion can be prevented by reducing the velocity of storm water runoff, especially on sensitive areas such as steep slopes and stream banks. Vegetated buffers, as wide as possible (24 feet minimum) should be placed in these areas to slow runoff and reduce erosion. This can be done by preserving existing vegetation wherever possible or, if no vegetation exists in the area, planting a variety of native species. For optimal success native plantings should be selected based upon the conditions of the location, not purely on aesthetics. If vegetation is not a viable erosion control option, geotextile fabric, riprap, or other materials can help to reduce flow velocity.

Irrigation strategies
When using plantings that require watering, cluster plants with similar moisture requirements and apply mulch. Watering should only be necessary after planting and during severe droughts. Drip irrigation is one of the most efficient forms of irrigation, especially on slopes where runoff would be high. Proper watering will depend on a number of factors including soils and current weather patterns. In general:

• Adjust timers on automatic sprinklers every week, depending on the weather.
• Avoid over spray onto impermeable surfaces.
• Maintain irrigation systems. This may involve repairing leaks, broken heads, and risers, as well as adjusting application patterns and rates to minimize runoff.

Lawn and garden care
General maintenance practices help increase the vigor of lawns and reduce the need for fertilizing, which is harmful to water quality. Keeping grass long will make the lawn thick and healthy and significantly shade out weeds. Avoid the use of insecticides and keep the soil aerated to encourage microorganisms and reduce thatch. Use mulch or compost around flowers, bushes, and trees. Mulch retains moisture and adds nutrients to the soil while reducing erosion and preventing the growth of weeds. Excess grass clippings, shredded leaves and shredded branches or plant trimmings make excellent mulches without being composted.

The University applies slow release, non-phosphorous fertilizers twice a year. All soil that the U-M fertilizes is tested prior to any application of fertilizer. Fertilizers are only applied in accordance with soil test results and recommendations.

The University employs Integrated Pest Management (IPM) methodology, an ecological approach to pest management. All available techniques are used to reduce pest populations while minimizing the potential impact of pesticides upon humans and the environment. Formulations of pesticides and fertilizers are designed to give the best performance for specific activities.

To further minimize the discharge of pollutants to the storm water drainage system, a chemical free buffer strip should be kept in lawn areas that border any streams or ponds. At the University, all priority 3 lawns are currently left untreated, but maintained to a 4 to 6 inch height to allow a more extensive root system to be established. By creating a deep root system and allowing a greater plant mass to be established, the soil is able to retain more storm water, which reduces soil erosion and sedimentation.

Equipment maintenance
Properly maintained garden equipment is another important factor in keeping the environment healthy. Oil, gasoline, and other fluids leaking from equipment may filter through the soil and into the groundwater or be washed by rainwater into a stream and eventually into the Huron River. Over time, small leaks can add up to many gallons of pollutants. Regularly inspect the equipment and immediately repair and clean up any leaks that are found. Prevent fuel and chemical spills by taking a few simple precautions:

• Remain in attendance when tanks and open containers are being filled.
• Use secondary containers whenever carrying materials from one location to another.
• Keep temporary fuel tanks in a bermed, paved area. Provide secondary containment for the entire tank volume.
• Use a funnel when transferring liquids from one container to another.
• Place trays under open containers and spouts of liquid storage containers.
• Avoid “topping off” fuel tanks. This is especially important on warm days when gasoline is likely to expand and potentially overflow. Gasoline poses a risk to both water and air quality.

Please visit the following links for more information regarding landscape design and practice:

Wild Ones – Native Plants, Natural Landscapes
The Springfield Township Michigan Native Vegetation Enhancement Project
Nichols Aboretum
Matthaei Botanical Gardens
Erosion Control: Saving School Girl’s Glen