Breach repair first step in Prime Hook refuge restoration

Audubon Society says marsh project costs may not be sustainable
At low tide, it's easy to see why some people are calling this section of Prime Hook National Wildlife Refuge at Fowler Beach a delta. Five years ago it was a thriving freshwater marsh. BY RON MACARTHUR
June 28, 2013

After reading a 113-page consultant's report on how to begin the restoration of Prime Hook National Wildlife Refuge's marshes by replenishing the beachfront, a statewide environmental organization says officials have not yet considered the full cost of the project.

David Carter, Delaware Audubon Society conservation chairman, had strong words for the proposed project because it does not consider the costs of restoring the marsh. He estimates the cost to restore the marsh behind the dune line at hundreds of thousands of dollars per acre, up to as much as $80 million. That's on top of an estimated $3.5 million to $11.2 million for beach replenishment. But, Carter said, the organization has no idea what the final cost will be until a final report on the entire scope of work planned at the refuge is published.

He said Audubon is concerned that the final cost might not be fiscally responsible and other alternatives may need to be considered.

“They want to pump sand without looking at the full cost; this project would be an incredibly expensive undertaking,” he said, adding the fix is not a long-term one. He said according to the report, the restoration will last about a decade.

Carter said a tipping point has been reached. He said it's time to look at other alternatives that could include the purchase of low-lying homes in flood-prone areas near the refuge – especially in nearby Primehook Beach – and establishing another road into the community along the barrier island via Broadkill Beach.

The project is the first step in the refuge's recently adopted 15-year comprehensive conservation plan. The refuge, off Route 1 near Milton, is made up of more than 10,100 acres, most of it wetlands.

Report lists alternatives for dune repair

The U.S. Fish and Wildlife Service released a report June 25 written by consultant Atkins Global outlining steps required to rebuild the dunes at Fowler Beach as the initial phase of marsh restoration. The full project entails rebuilding salt marsh in three of the refuge's four impoundments.

The study includes environmental survey results, project overviews, conceptual project designs and potential sites to get material to build up the dunes and fill in the Fowler Beach breaches. The report outlines five alternatives to rebuild an 8,900-foot section of beach just north of Primehook Beach to Fowler Beach Road. Two of the alternatives would totally fill all four breaches; three would leave one breach open. Estimates for the alternatives range from $6 million to more than $11 million.

Alternative 1 would cost $8 million, using 426,000 cubic yards of sand to create a 20-foot high-dune and a 55-foot berm; Alternative 2, at $11.2 million, would use 725,000 cubic yards of sand with a 40-foot-high dune with a 110-foot berm.

Three other alternatives – leaving one breach open – would cost $3.5 million to $11 million using from 275,000 to 667,000 cubic yards of sand.

The U.S. Fish and Wildlife Service has $20 million to repair damage in the refuge caused by Hurricane Sandy.

The report stresses that any beach replenishment must be accompanied by marsh restoration. “Back-barrier marshes provide the platform on which beaches/dunes inevitably migrate. In the absence of marshes, the platform is eroded and the beach/dune migration is accelerated. Fundamental to the success of any replenishment project at Prime Hook is restoration of the marsh. Restoring the marsh will help to restore the barrier system processes that control the landward beach/dune migration and restore valuable fish and wildlife habitat,” according to the report. Work on the project is expected to begin in 2014.

“This project needs to be sustainable. It looks like they want to spend a lot of money and accomplish a very little. There is no protection for Prime Hook Road or the community,” Carter said. “It will not provide the level of protection people were hoping for. It is a false sense of security.”

Carter called the proposed solution a political one. “ This will get through an election cycle but not solve the problem,” he said.

In addition, Carter said, Audubon is concerned where the sand would come from for the beach replenishment project. He said if it's spoils from the Delaware River channel deepening project, it could have unintended and serious environmental consequences on the recovering horseshoe crab population that spawns along the Delaware Bay coastline.

He said the fine-grain sand from the channel could be detrimental to horseshoe crabs. He said over time the coarseness of the sand would work itself out, but there is still a potential risk. “Are they willing to risk 25 percent of the horseshoe's habitat for two to three years when its just starting to recover?” he asked. “We don't see data there that this would not present a danger.”

Problems started several years ago

Two of the refuge's four impoundments, Units 2 and 3, were historically salt and brackish, but dikes were built in the 1980s creating two freshwater marshes. Over the past five years, portions of these impoundments have reverted to saline conditions, largely due to recent storms that caused flooding, erosion and several breaches along the barrier island fronting the refuge. Because of the breaches, sections of the refuge have been inundated with saltwater, resulting in the loss of vegetation, predominantly in Unit 2 and Unit 3. The effect in Unit 2, and starting in Unit 3, has been a shift to an open saltwater system.

In 2006, storm surge from offshore Hurricane Ernesto caused the first significant overwash at the refuge in Unit 1, a saltwater marsh. A pair of nor'easters in May 2008 and November 2009 opened two significant breaches at the dune line protecting Unit 2, which at the time was a freshwater marsh. Although neither storm made landfall in Delaware, Hurricane Irene in 2011 and Hurricane Sandy in 2012 only intensified the problem. Refuge biologist Susan Guiteras said four major breaches are now open allowing for free flow of saltwater from Delaware Bay into the refuge.

Guiteras said the shoreline along the refuge receded 300 feet from 1928 to 1992. “But it's only taken another 20 years to recede another 200 feet,” she said.

Guiteras said the shoreline along Fowler Beach has eroded at a rate of about 10 feet per year over the past decade. She said at that pace it will erode 1,000 feet by 2100.



1911 – Storms close outlets of Prime Hook and Slaughter creeks to Delaware Bay.

1930s – Ditches are dug to control mosquitoes and also manage water levels until the 1950s.

1963 – U.S. Fish and Wildlife Service establishes refuge; no water management occurs until 1980.

1980s – Freshwater impoundments are created for waterfowl and to control phragmites. Water-control devices eliminate all tidal flow to 4,000 acres of marshland in the refuge.

1986 – An environmental assessment finds saltwater from Delaware Bay would eventually intrude into the marshes.

1988 – First dune restoration project followed by restorations in 1992, 1998, 2006, 2008 and 2011.*

2006 – Washover into Unit 1 caused by offshore Hurricane Ernesto.

2008 – Mother's Day nor'easter causes minor overwash that is repaired.

2009 – Major nor'easter in November opens two significant breaches into Unit 2.

2011 – Breaches widened by storm surge from Hurricane Irene; Prime Hook Road is closed for six days.

2013 – Strong waves from Hurricane Sandy create the most damage to date; four significant breaches are open into Unit 2.


*In 2011, an overwash occurs four days after the project is completed. Officials say 80 percent of the sand needed to rebuild the dune was washed away by Hurricane Irene.





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