CHATHAM — The owners of the Little Beach condominium that was inundated in several storms last winter are seeking to build a dune to protect them from additional flooding.
Engineer Don Munroe of Coastal Engineering said his clients would prefer to use sand dredged from the waters off Outermost Harbor to build a 10-foot-high dune between the condominiums and the water. But he told the conservation commission last week that, should the dredging not be possible, they would like permission to build a seven-foot-tall dune using sand trucked in from upland sources.
The elevation of this dune would be somewhat lower, “only because the cost of upland sand is more than dredged sand,” Munroe said.
Conservation Commission Chairman Michael Tompsett asked whether the new dune would seal off the condominium from ocean flooding, “or can water come around the back?”
The dune would only protect the seaward side of the property, and so water is still likely to come around the end, Munroe replied.
“This is more to keep the nuisance water out, not the heavy, heavy high surge water,” he said. “That’s going to have to be dealt with in a different fashion,” and talks are underway with other property owners and with the town to come up with a solution, Munroe said.
Commissioner Dee Dee Holt asked when the property owners are planning on deciding whether to build the dune using dredged sand under an existing application, or to go ahead with upland sand.
“What’s the trigger date for this application?” she asked.
Munroe said there is no firm date, but his clients are hoping to have a dune in place before the arrival of coastal storms in the fall and winter. Permits for the dredging near Outermost Harbor have not yet been issued, he said.
The property owners are also asking permission for the installation of an underground structure similar to a catch basin that would receive water pumped from the condominium’s basement by a sump pump.
Condominium association President John Hausner said the basement floods during extremely high tides, but not with salt water. The fresh water aquifer in the area floats on top of the salt water, “so when we get these super tides a number of times a year, it actually forces water into the crawlspace and the basement of the units,” he said.
The conservation commission will discuss the application again on Aug. 22.