WESTERLY — Combined, the town spent about $1 million cleaning up after Superstorm Sandy and Tropical Storm Irene. Town Engineer Paul LeBlanc thinks he’s found a way to greatly reduce those costs and protect the dunes at the town’s two beaches.
LeBlanc has designed a system that employs non-biodegradable bags filled with sand and planted about 7 feet below the surface of the dune to act as a kind of unseen shield designed to defuse the power of waves and the type of surge the two notable storms churned up.
If it works, the system would greatly reduce the amount of time and money the town spends on removing sand from Atlantic Avenue and other areas it is pushed to during significant storms. The system is estimated to cost about $65,000. LeBlanc intends to seek funding for 75 percent of the cost from the Federal Emergency Management Administration as part of the town’s post-Sandy recovery effort.
LeBlanc cautioned that, even with his proposed system, some of the sand on and around the dunes should be considered “sacrificial,” meaning some of it would be disturbed. Also, the proposed system would be effective, LeBlanc said, in combating the strength of waves from a “one in 25 year” magnitude storm but would not withstand the power of more powerful and destructive events such as the hurricane of 1938, considered to be a “one in 100 year” event.
New regulations approved by the Rhode Island Coastal Resource Management Council (CRMC) in October allow 38 property owners on the Misquamicut coastline to employ experimental erosion control measures. The properties run from 31 Atlantic Ave. to 149 Atlantic Ave., an area CRMC describes as the Misquamicut headland. CRMC has said the experimental measures, if approved, would have to be reviewed in three years.
LeBlanc has designed plans to employ the bag system at Wuskeneau Town Beach, an area not currently eligible for experimental measures because it is considered a barrier beach, distinct from the headland area.
LeBlanc has been in touch with CRMC officials and plans to meet with them again this week. He is hopeful the council will sign off on his plan as a means to protect the town’s investment in the dunes, which were rebuilt after both Tropical Storm Irene and Superstorm Sandy.
Grover Fugate, CRMC executive director, confirmed that the council is involved in discussions with LeBlanc, but said the headland and barrier beach are viewed differently because erosion occurs at different rates and the two areas are subject to different types of wave and tidal forces. Barrier beaches, Fugate said, tend to be more dynamic, losing sand at times but then regaining it through natural processes. Headland areas are more likely to erode only, resulting in lost beach area. So-called “hard measures” such as sea walls and the use of large rocks or boulders actually promote erosion, essentially “causing a loss of the beach,” Fugate said. CRMC is working with a few Misquamicut-area property owners who erected illegal sea walls after Superstorm Sandy to have the walls taken down, Fugate said.
The rules allowing consideration of experimental measures are, in part, a response to criticism that CRMC is resistant to trying new approaches, Fugate said. The council has scanned some of the methods used in other parts of the country, but has yet to find a method that seems like it would work.
“We haven’t really seen anything that says ‘that’s the answer,’” Fugate said.
Despite the council’s skepticism, Fugate said officials will review plans developed by property owners. The council did not specify which methods might gain approval. If approved, systems will be monitored for effectiveness and to ensure they are not aggravating erosion or causing other problems.
LeBlanc’s plans call for the use of Trapbags, a proprietary product being used in New Jersey and New York as part of those states’ response to Superstorm Sandy. Fugate acknowledged measures being taken in those states, but noted that the shoreline in those states is more developed than in Rhode Island.
Under LeBlanc’s plan, 6-foot-tall bags will be filled with sand and buried in a three-bag-wide, 100-foot-long segment. The entire stretch is covered with geotextile mats. Additionally, bags will be buried beneath areas that are cut out to allow access to the beach.
When a storm is predicted those areas will be “plugged” with sand, a process LeBlanc said would take no more than three hours.
“Each 100-foot section weighs 400,000 pounds so its a pretty robust system,” LeBlanc said.
The bags are expected to last for about 20 years before they would have to be replaced. They will be filled with existing sand that is already at the beach.
The project would address two criticisms that beachgoers had during the 2013 beach season — the slope leading to the beach and the size of the beach area. By re-engineering the profile of the dune that was rebuilt after Sandy, the slope to the dune will be more gradual, making it easier to enter and walk on the beach. The project would also result in an additional 30 feet of beach area, LeBlanc said.
The top of the dune would be boosted to 16 feet above sea level from its current rebuilt level of 14.5 feet above sea level.
LeBlanc hopes to get rapid approval for the project so that the dune can be stabilized with dune grass the town has ordered and plans to plant in April.
Dune grass divide
The town’s plans to plant dune grass highlight some of the disagreement on how best to preserve developed coastal areas.
The plans stand in contrast to Fugate’s contention that the plantings actually have a counter-productive effect, leading to “narrower, more vertical dunes” instead of wider and lower ones that, he said, offer greater protection and sustainability. Fugate said officials with the state Department of Environmental Management recently asked for CRMC’s input on dune grass.
“DEM approached us and we told them, ‘If it was us, we wouldn’t spend the money on (dune grass),’” Fugate said.
LeBlanc reviewed his plans with the Town Council in early February.
Councilor Christopher Duhamel called the system “a common-sense way to create a fail-safe dune that won’t breach.”
Councilor Caswell Cooke Jr. said he hoped the state would consider developing a system of incentives to encourage property owners to use the experimental measures.