Even though Houston is a long way from the Carolinas, the impact of Hurricane Harvey on Texas’s largest city still sent chills up the spine of anyone living in a hurricane-prone area. A combination of overdevelopment and poor wastewater management caused catastrophic flooding and an estimated $180 billion in damage. Not all cases will be this extreme, but homeowners and cities alike are rethinking stormwater runoff management. Permeable pavers like those installed by Unit Paving are one facet of a sensible runoff management plan.
How Permeable Pavers Work
When you understand how permeable pavers work, you can begin to understand how they help to manage stormwater runoff. Permeable paving lays interlocking pavers over a substrate of gravel, crushed stone, or even grass. Small ¾ in. stone is put between the pavers themselves preventing the pavers from shifting but still allowing water to pass through. In contrast to impermeable paving, which sheds water, permeable pavers return water first to the soil, then — eventually — to the local aquifers. This process also filters out pollutants that could otherwise contaminate the local supply of drinking water.
Runoff Management Benefits of Permeable Pavers
Less Municipal System Load
Under normal circumstances, a municipal sewer system can handle a bit of rainfall. However, impermeable surfaces combined with 21st Century infrastructure atop a sewer system built a century ago (or longer) can be a recipe for disaster. Permeable pavers return water to the ground instead of diverting it to storm drains. Sustainable hardscape design using permeable pavers can also limit costs and build complexity, since drainage needs are typically smaller.
Reduced Soil Erosion
Runoff from impermeable paved surfaces undermines the soil in surrounding areas. This is especially true if the paved area abuts a grade or a steep slope. The fact that permeable pavers sequester and filter water means retaining valuable nutrients in the soil, keeping plant life healthy and providing another hedge against erosion. Some paving solutions are also designed for the sole purpose of keeping soil in place, which means less sediment in storm drains, less maintenance, and fewer costly repairs to the surrounding softscape and storm drains alike.
Soil erosion has consequences beyond the potential for desertification. In extreme circumstances, soil erosion can undermine roads, sidewalks, and other paved surfaces. It can also cause costly foundation and structural damage.
Reduced Risk of Flooding
Flooding happens because the volume of water falling or entering an area at any given time is more than drainage systems can handle. Storm drains and pipes will always be a fact of life, but incorporating permeable pavers into a municipal hardscape design reduces the amount of water flowing to those drains, making it easier for them to do their jobs. That, in turn, means less flooding.
Residents of the Carolinas are no strangers to extreme weather. Hurricane season hits harder here than most of the rest of the United States, which makes long-term planning an absolute necessity. Whether you’re a property owner, a business owner, or a municipality concerned with sustainability and stormwater runoff, a permeable paver consultation with Unit Paving can help you manage risk.