In the past few weeks, a tropical disturbance that originated in the Gulf of Mexico has dropped many consecutive inches of rain on cities across the East Coast. As a result, hundreds of homes and businesses were damaged or destroyed, and several people lost their lives. Here in Roanoke, massive flooding shut down roads, felled power lines, and swept cars off the street. Needless to say, water has immense destructive potential, and the exterior features of a home—landscapes and hardscapes—are often most vulnerable to damage. During this past flood, one of our client’s witnessed a waterfall of flood water and debris pour over a retaining wall we recently installed into her back yard. The retaining wall survived the onslaught (thanks to the outstanding craftsmanship of our crew) but the rest of her yard was, unfortunately, crippled.
In truth, there is no flood-proof landscaping design. Flooding can happen to anyone and, when it does, your personal safety should always come before preserving property. But, there are ways saavy landscape designers can manipulate an existing landscape and help fortify it against flood damage. The key to creating a flood-resistant landscape is planning ahead and including thoughtful design elements that utilize natural solutions to combat natural risks.
In urban and suburban environments, storm-water runoff is a primary cause of flooding. Often, existing roads and walkways lack the necessary infrastructure to channel excessive runoff to sewers and drains, increasingly the likelihood that excess water will pool in residential yards and driveways. However, there are some age-old flood mitigation tactics that still work well fortifying modern yards against flooding.
Swales, depressions in landscapes that direct water drainage, are simple to install and work well as “natural sewers” for rain-water runoff. Well-designed swales slow water flow in addition to redirecting it. Installing deep rooted plants at the swale’s edge or placing sturdy rocks in the bottom of the swale’s well can accomplish this easily. Note: swales do not stop the flow of water, so they must drain out to an area that can accommodate excess waters: a dry well, for instance.
Rain gardens, another easy-to-install landscaping addition, provide a safe place for excess water to pool during a storm. As an added bonus, rain gardens are highly efficient and channel rain water back into your garden, decreasing run-off and risk of evaporation during hot days. For a guide on how to build a rain garden, check out this blog post of ours!
Downspout diverters are small but essential flood fighters. They cheaply and efficiently channel storm-water runoff away from walls and houses, helping fortify the most vulnerable parts of properties from flood damage.
Driveways are often hyper-vulnerable to flooding because they are made of asphalt and concrete—impermeable materials. However, driveways can be manipulated to channel storm water more effectively. Permeable driveways, such as those made out of gravel or permeable paver stones, are much more flood-resistant. Additionally, adding drainage to the sides of impermeable driveways can significantly improve a driveway’s flood-hardiness.
These simple tips could go a long way in preventing future flood damage at your property. When building your landscape, remember to ask your landscaping professionals about flood mitigation techniques and flood-smart designs.