Laurel’s new permeable parking lot

You cannot tell it is raining from this picture at the new parking lot, but it has in fact been raining pretty hard on November 11, 2022 near midday. Looking at the more distant parking lot, one can see the ponding and overflow that quickly formed and is streaming water into Main Street.

L4P applauds the City's initiative to reduce stormwater run-off at the source. The picture of the new parking lot next to Wings and Things on Main Street compared to the adjacent parking lot speaks volumes (of water literally).  During a November rainstorm, minor flooding at Main and Route 1 had significant contributions from the adjacent Senate Building parking lot, which has a non-permeable asphalt surface. That non-permeable surface acted as a fast-moving rain funnel emptying polluted stormwater into the street, which flows into the stormwater drain and then dumps directly into the river. No water at all could be found leaving the new permeable surface parking lot, which is able to hold at least an inch of water in its subsurface repository.

Permeable or pervious asphalt allows water to pass through the surface although it appears otherwise indistinguishable from regular blacktop. It acts as if it were soil, quickly absorbing and preventing stormwater runoff.  Permeable asphalt requires minor additional labor, expertise and expense to excavate a gravel-filled catchment basin below the asphalt. Any additional expense is more than offset by reduced need for stormwater retention ponds and underground piping.  

An alternate but equally effective parking lot design for capturing stormwater can be seen at the Laurel library, where permeable pavers are used. These are both great examples of environmentally responsible management that enhance the city infrastructure.  Parking lots are an important though environmentally harmful feature of cities, and any effort to mitigate their impact on the environment is appreciated. The fact that permeable pavement is affordable and reduces the potential downstream (pun!) pressure on stormwater management systems can reduce long-term costs of new or expanded stormwater piping.

More importantly to the Patuxent River, these permeable pavement solutions reduce stormwater runoff from rapidly entering the river and exacerbating flooding and pollution.  While not a panacea, it shows one more piece of the sustainability puzzle that can benefit the Laurel community and wildlife if more widely implemented (such as at the nearby asphalt parking lots).

For more information on the permeable pavement, there is an interesting and informative EPA resource here