Runoff is a major problem in urbanized areas like major cities and suburbs, where stormwater can also damage local streams and lakes. A major contributor to this degradation is pavement. Your home’s driveway, your street, and your sidewalk are all leading to oil, nutrients, and other pollutants entering your watershed. But now, there are ways you can remedy this. Multiple low impact development options are available, including permeable pavers, paving grids, and permeable concrete.
Permeable paver walkways can reduce your household’s pollution without detracting from its curb appeal. These walkways look like traditional sidewalks, but with spaces between and underneath pavers to absorb the rain and snowmelt. They are composed of three layers: 12 inches of crushed stones or gravel on the bottom, 6 inches of pea stones in the middle, and the layer of pavers on the top. You may want to contact a contractor depending on the scale of your project and budget.
Other absorbent pavement technologies include pervious concrete. This porous concrete is composed of interconnected voids of large aggregates (no fines like sand), which allow water to readily pass through at a rate of 3 to 5 gallons per minute (exceeding the flow rates of most storms). When water makes contact with this surface, it percolates down through layers of gravel, helping to purify the water and infiltrate into the soil along the way. The strength of these pavements is on par with standard paving methodologies, and can usually withstand the freeze-thaw cycles that occur in the winter.
Maintenance for these systems is relatively low, thus making it an excellent choice to improve your home’s rainwater management. Some pavement systems may not quite be durable enough to use on major roads, but would also be excellent options for parking lots and sidewalks throughout urban areas. Permeable pavement options have the additional potential to reduce flooding while increasing groundwater recharge.