Outer Banks, an attractive spot on the map, year after year remains vulnerable to weather anomalies. During hurricane seasons and nor’easters, homeowners are seeking ways to protect their properties from ocean water intrusion. But could you have any sort of control over waves, wind, surge, flood. In fact, you can by protecting dunes through beach grass planting.
Sand dune is an essential natural barrier that protects oceanfront properties from destructive forces such as hurricanes, waves, flood. By absorbing the effects of high waves and surges, they delay and often times prevent damage to inland areas. Under normal weather conditions, sand moves back and forth, rebuilding beach and dunes. However, weather anomalies like hurricane and surges can cause dramatic sand losses also known as dune erosion.
Yet, dunes are more effective and resilient if there is natural vegetation planted. This vegetation helps to preserve and stabilize dunes in coastal areas. Having adopted to survive harsh weather conditions such as high temperatures, salt, strong winds, and flooding, beach grass developed strong root systems, leaves and stems that prevent water loss, and low-lying growing method which protects sand from wind.
Now, what kind of beach grass should you plant? A study on Biogeographic Implications for Dune Shape and Coastal Protection examined four dune grass species along a 320-kilometer distance across the OBX to determine how their structure, both above and below the sand, affects sand accretion around the plant. This has direct implication to the shape of dunes and their stability.
According to the study, American Beachgrass has dense shoots which gives the greater sand accretion compared to other species. Typically, it builds tall and wide foredunes, if combined with fast lateral spread. Study also concludes that it has better coastal protection qualities compared to other species. Sea Oats demonstrated 42% sand accretion. It can help build more steep and narrower dunes if combined with slow lateral spread. Bitter Panicum appears to have similar sand accretion rate to Sea Oats. Finally, Saltmeadow Cordgrass does not cause much of dune elevation change, but still could contribute to coastline protection.
Reporting on the aftermath of nor’easter 2019 in Hatteras Island Jonathan Petramala with Accuweather noted that dunes with vegetation remained unaffected and protected the properties compared to ones without any beach grass. This cannot stress the importance of beach grass enough.
If you own an oceanfront property, consider strengthening or planting a vegetation line for dune stabilization. Late fall and early winter, when the weather is cool, is the best time to do that. See detailed planting instructions here.