Pervious surfaces are permeable, allowing water to pass through and into the ground. These materials have come into favor as many communities limit the impervious coverage on a parcel (total square footage of buildings and paved areas) in order to limit storm drain run-off. There are a few preferred types, including gravel, decomposed granite, natural stones, permeable concrete, permeable pavers, and a grass lawn. Keep in mind: Contrary to popular belief, tightly joined interlocking pavers or bricks on sand do not allow water to pass through. Drainage systems must be incorporated into the plans. With additives, gravel and decomposed granite can be rolled and compacted as hard as asphalt but still smooth enough for chairs and wheeled carts.
Natural stones on a gravel base allow water to drain between the blocks while also providing a stable expanse for tables and chairs. The spaces between the stones can be filled with low ground covers.
Permeable concrete is a relatively new product which can remain cool. A dry mix of large aggregates and rocks are held together with binders and cement, which can be colored and stained. Gaps are left between the rocks, allowing water to flow freely. Over time, the spaces may fill with dirt, reducing the permeability of the surface.
Lawns can be brought to the edge of a swimming pool. Before retrofitting an existing pool, determine if it can handle being “deckless.” Wet and saturated soil behind a pool may place stress on the structure that it was not designed to withstand. For a new pool project, money spent on a few extra inches of concrete is more than offset by the savings on the cost of a pool deck.
Lawns and plants actually do well adjacent to a swimming pool. The biggest hazards are sun damage to the lawn from plastic toys left in the sun and yellowing grass from objects forgotten for days. Within acceptable ranges, chlorine will not hurt most sods and plants, but water from saltwater pools has been known to damage soft marble decks, copings, lawns, and plants.
Photo courtesy of Aquatic Consultants, Inc./Brian Van Bower, Miami, Fla.; photography by Brian Van Bower; architect, Rene Gonzalez