Huge gates that could be slammed shut when major storms approach would be built across the mouths of three inlets in New Jersey, closable barriers would cut parts of two bays in half, and 19,000 homes would be raised as part of a $16 billion plan to address back bay flooding, one of the major sources of storm damage at the Jersey Shore.
After five years of study, federal and state officials unveiled recommendations Thursday that would drastically change the appearance of some iconic spots at the shore.
It also would be one of the most ambitious and costly efforts any U.S. state has yet taken to address back bay flooding. This refers to floods that are not primarily caused by waves crashing over ocean barriers, but by stealthily rising water levels in bays along inland shorelines.
Although ocean waves caused severe damage during Superstorm Sandy in 2012, back bay flooding also caused extensive damage in that storm. In numerous places, it was the primary source of property damage during Sandy.
“To better protect New Jersey’s residents, communities, and economy, we must plan and prepare today for the climate change risks of tomorrow,” said Shawn LaTourette, New Jersey’s environmental protection commissioner.
The plans announced by the U.S. Army Corps of Engineers and the state Department of Environmental Protection are just that: plans. There is no guarantee of funding for the massive project, which would run from Neptune in Monmouth County all the way to the state’s southern tip in Cape May.
It calls for large storm gates across the Manasquan, Barnegat and Great Egg Harbor inlets. In addition, so-called “cross-bay barriers” would be erected in Absecon Bay near Atlantic City, and along a former railroad right of way that would extend along 52nd Street in Ocean City.
These bay barriers would have a swing gate in the middle that could be shut during major storms, and slat-like gates spanning about a third of a mile that would be lowered down into the water to block surges of water during storms. The structures would rise about 20 feet over the water, LaTourette said.
Similar barriers have been proposed for waterways in New York like those already in place along the Mississippi River and in Venice, Holland and England. But other places, including Boston, considered the idea but decided the cost outweighs the benefits.
Some environmental groups oppose such barriers, fearing the structures would restrict the tidal flow and sediment transport, and impede the migration of fish, including striped bass.
Others want more natural remedies, including wetlands restoration and expansion, dune construction, and a halt to rampant construction along the water’s edge.
“It’s not a surprise that the Army Corps wants to built it big: That’s what they do,” said Tim Dillingham, executive director of the American Littoral Society, a coastal protection group. “When you only have one tool in your kit, that’s the one you use.”
Dillingham said the state should use more of the proposed $16 billion in funding to buy and demolish homes in flood-prone areas. The state already has such a program, but it has not bought a single home along the ocean because no one thus far has wanted to give up their valuable real estate. Most of its purchases have been near inland rivers and other smaller waterways.
A crucial question remains to be determined: Just who decides which storms are major enough to slam the gates shut and how often will they be closed? David Rosenblatt, New Jersey’s chief resiliency officer, said either the state or federal governments could be tasked with that responsibility.
And the plan calls for elevating 18,800 homes along the Shark River, including Belmar and Lake Como; southern Barnegat Bay including Long Beach Island, Tuckerton, and Egg Harbor; Absecon Bay, including Brigantine and Absecon; and the southern shore from Strathmere to Cape May Point.
The costs are eye-popping, not even including the $196 million a year it would take to operate and maintain the flood control gear. The federal government would pay $10.4 billion, with the rest coming from state — and possibly local — coffers. Dillingham said the proposal is the most ambitious and costly state-level flood control project he can recall in the U.S.
Although the report acknowledges back bay flooding is exacerbated by rising sea level, the proposed engineering solutions are designed to protect only during the most serious storms, and are not a cure for steadily rising seas, LaTourette said.
Additional flood control measures can be added in future phases of the plan, officials said.