A situation in South Carolina highlights the ongoing debate over the efficacy and value of erosion control measures. An experimental wave dissipation system is being used on parts of Harbor Island and the Isle of Palms to curb erosion. Environmental groups say the system interferes with turtle nesting, preventing the turtles from coming ashore and laying their eggs. The turtles are a threatened and federally protected species.
The system consists of horizontal pipes fastened to offshore posts; it is intended to reduce wave impact and encourage the buildup of sand along the beach. The pipes can be removed during turtle mating season—May through August—although this year they were left in place while a study tries to determine the effectiveness of the system.
As this article from The Beaufort Gazette reports, the state had ordered the system, which was paid for by local homeowners, to be removed this week, but the homeowners are challenging that order, saying the system should be left in place until the results of the study are known.
Environmental groups, meanwhile, say “false crawls” show that the system is disrupting the turtles’ nesting behavior. Tracks show that turtles have walked up the beach in front of the system but returned to the water without laying eggs. Volunteers who track the turtles’ progress on Harbor Island, however, say that a greater-than-average number of turtle nests have been discovered there this year.
Many different erosion control measures—particularly those intended to stop coastal erosion—have been hotly debated. Sea walls, which definitely protect the area immediately behind them, are criticized for disrupting the natural movement of sand along the beach and possibly exacerbating erosion elsewhere. If the process of erosion continues as it did before the wall was built, the wall itself becomes the shoreline and any sandy beach in front of it is lost to the public. Some states ban or limit their use.
Similarly, the process of beach nourishment—adding sand to an eroding beach—has often been controversial. Is it worth the price, when the process of erosion will continue and more sand will likely need to be added? Who should pay for it? What’s the source of the sand, and is the process of dredging it from offshore disrupting habitat?
The outcome in South Carolina—whether the wave dissipation system must be removed or can stay permanently—will be determined by the state’s Department of Health and Environmental Control. The other debates are not so easily decided. What has your experience been with beach nourishment, hard-armor structures to protect the coastline, or wave dissipation systems?
StormCon Is Seeking Moderators
If you plan to attend the StormCon conference in Indianapolis, August 22–25, consider stepping up to moderate one or more of the technical sessions. The full conference program is now online, and many 60- and 90-minute sessions are still available. Please contact me ([email protected]) or Brigette Burich ([email protected]) for more information or to reserve a session.
Janice Kaspersen
Janice Kaspersen is the former editor of Erosion Control and Stormwater magazines.