Grass lawns threaten Lake George because they replace a beneficial shoreline buffer and require maintenance and do not adequately manage stormwater.
Expansive grass lawns are popular around Lake George. People take pride in the maintenance of their yards and see a lush green lawn as an asset to their property. But, it’s important to know that grass lawns negatively impact Lake George water quality in three principal ways: 1) Square-foot-for-square-foot, a typical grass lawn infiltrates significantly less rainfall and stormwater runoff compared to a natural forest; 2) Large lawns that extend to the lakefront increase nutrient and stormwater runoff from developed sites and uplands; and, 3) A regular part of lawn maintenance often relies on the high use of fertilizers and pesticides, which largely end up in the lake, degrading water quality.
Ineffective Stormwater Infiltration Begins with the Construction Process
The negative impacts of lawn management begin during the process of land development. Grass lawns often grow on top of soil that has been compacted during construction and excavation. Bulldozers remove topsoil and heavy trucks that carry concrete and other supplies compact the soil on the site. When construction is completed, 1–2 inches of topsoil are spread on the graded site prior to seeding a lawn. The ground by this time is usually so hard that grass roots cannot penetrate the surface below the topsoil. As a result, stormwater flows from the site in what’s called “sheet flow” or “concentrated flow” rather than infiltrating into the ground. Stormwater will travel quickly just below the grass roots picking up sediment and nutrients on its way to Lake George.
Dominant grasses that grow around Lake George have short roots, usually around two inches or less compared with native plants with roots as deep as 18 inches or a tree that grows roots several feet into the ground. In short, the longer the roots, the greater the ability to infiltrate runoff. Figure 22 illustrates this concept.
Lawn Size and Lawn Management are Major Issues
Large grass lawns planted to the edge of the lake are a major source of nutrient pollution, which feeds the algal blooms in Lake George because there is limited infiltration to intercept the increased stormwater runoff. Lawn size should be reduced in order to minimize nutrient loading and improve stormwater management.
- Expansive grass lawns threaten the water quality of Lake George.
- A typical grass lawn infiltrates significantly less stormwater runoff from rainfall than does a natural forest.
- Large lawns that extend to the lakefront create a condition that allows excessive nutrients and stormwater runoff from the developed sites and uplands to enter the lake.
- Lawn size should be minimized and include trees, rain gardens and buffers along the lakefront and streams.
- The use of large amounts of fertilizers and pesticides as a regular part of lawn care maintenance degrades the water quality of Lake George.
30% of water used in the eastern United States is used for watering lawns.
18% of municipal solid waste is yard waste.
Lawns are highly productive. For instance, just one acre of lawn can produce more than five tons of grass clippings in a single year. These clippings are rich in nutrients. Consider that one bushel of freshly cut grass clippings contains enough phosphorus to produce 30–50 pounds of algae in the lake.
Many property owners around Lake George exacerbate poor stormwater management by using large amounts of fertilizers, herbicides and pesticides as regular lawn management practices. These practices greatly increase the loading of chemicals and nutrients into Lake George. See the next section for information about the hazards of using fertilizers and pesticides.
A lakefront lot maintained in a natural forest state is the best alternative to grass lawn. For landowners who want a grass lawn on their property, there are a number of ways to mitigate damage to the lake:
- Limit the size of a grass lawn.
- Plant or maintain a shoreline or stream buffer and a rain garden.
- Mow the grass to a height of three inches or more to promote food production for the grass.
- Leave grass clippings on the lawn as a natural fertilizer. > Do not use fertilizers, herbicides or pesticides.
Grass lawns are popular around Lake George, but are a property management practice that can be harmful to the lake. The alternative is to minimize the size of your grass lawn and to replace lawn area with shoreline buffers, rain gardens, and wild areas, all of which will help to protect the water quality of Lake George.