Permeable surfaces allow water to infiltrate and soak into the ground. Soils naturally let rain water soak in. Impermeable surfaces do just the opposite.
When the water hits this kind of surface, instead of soaking in, it runs off across the surface, collecting pollution, nutrients, trash and sediment. This is why stormwater runoff creates such a problem in the steep watershed of Lake George. The more impermeable surface area there is, the more stormwater runoff.
The image to the right shows that impervious cover increases, it goes from most of the water being evaporated or infiltrated, to most of the water running off. This drastic alteration of the natural water cycle creates many changes that must be managed in order to protect what is at the bottom of the watershed: Lake George.
Proper stormwater management practices must accompany development in order to keep the Lake protected. The key to decreasing stormwater runoff and the pollution associated with it is to decrease the amount of impermeable surface area! Here are some ways that you can do that on your own property.
Runoff from 3 inches of rain. Image courtesy of landscapesforlife.org.
- Keep paved driveways as small as possible. Use permeable surfaces for overflow parking areas that aren’t needed on a regular basis. While gravel driveways may start off permeable, over time the compaction makes them just as impermeable as regular asphalt.
- Rooftops are impervious too — so keep your home a modest size (which will save you money on utilities as well) and build up — not out — on lake shore lots.
Examples of permeable pavement
The top photo shows interlocking concrete pavers on a residential driveway in Lake George. Homeowner John Kearney estimates the pavers capture as much as 3/4 of the stormwater coming from streets and properties uphill from his property. The center photo shows a traditional stone pathway that has more than the traditional space between the paver steps. The photo at right illustrates the dramatic difference in the stormwater absorption ability of porous asphalt (in the foreground) vs. traditional asphalt (in the background.) This product's strength and durabiity have increased, while its cost has decreased. It offers many advantages for commercial applications, including parking lots, driveways and roadways — it was used on Beach Road and the Million Dollar Beach parking lot in a 2011 project.
Contact the Lake George Association for more information on permeable pavement projects and advice on contractors.