Gov. Chris Christie must make a decision on Monday about whether or not he will sign a bill that some advocates warn could put state residents' flood insurance policies at risk.

If signed, the bill would allow developers to put apartment buildings and other types of developments on existing piers in the Hudson River. Developers have worked for years on projects in towns such as Weehawkin, but in December, new flood maps through the Federal Emergency Management Agency designated much of the immediate shoreline and lower Hudson River into the highest risk velocity zone.

State regulations currently limit construction on piers over the water in velocity zones to Atlantic City, a provision allowed in the 1980s as an incentive to the casino and tourism industry. However, according to FEMA regulations, such construction does not conform to National Flood Insurance Program regulations.

But, advocates warn, if Christie were to sign Senate Bill 2680, the act alone could trigger FEMA to suspend the state's participation in the National Flood Insurance Program. The program's rules require that states and towns that participate in the program - giving home and business owners access to flood insurance policies - must maintain laws and regulations that promote "sound floodplain management."

Suspension from the program could mean homeowners in flood zones would not be able to renew their flood insurance policies, could halt real estate closings where the buyer needs flood insurance and end all federal grants in the affected towns or state.

The stakes of either outcome - signing or vetoing the bill - are huge. The choice is developers investing hundreds of millions of dollars into urban cities struggling to redevelop waterfront property or putting the state's participation in the flood insurance program at risk, said John Miller, legislative affairs chair of the New Jersey Floodplain Managers Association.

Proponents of the bill say that the buildings could be constructed safely and would be well above flood levels. State Sen. Nicholas Sacco, D-Bergen, Hudson, a co-sponsor of the bill, said last month the bill only applies to municipalities that want this type of development. Sacco said only about five piers would be considered eligible.

And the fact that Atlantic City allows commercial development on piers over the water in velocity zones was a key reason Sacco said he introduced his bill, which passed both houses of the Legislature by wide margins.

In May, the Department of Environmental Protection held a stakeholder meeting to discuss the issues relating to building on piers in velocity zones and whether the practice could be done safely. Stevens Institute coastal engineering professor Tom Herrington was among those in the meeting and said he was asked to discuss the engineering aspects of the practice.

"We have built structures for naval facilities, shipping terminals, in velocity zones, in very hazardous areas around the world," he said. "It can be done."

The biggest concern engineers have when designing such a structure, Herrington said, is whether the building and pier piling would withstand a large ship ramming into the structure. From a flood-design standpoint, engineers and designers need to make sure the height requirements and construction standards far exceed minimum building standards.

"I think the concern is will developers invest money to build to that standard? The Navy certainly will do that, but they have a lot more money than a commercial developer," Herrington said.

Christie's office did not respond to a request for comment Friday. The office previously has said it does not comment on whether the governor will sign or veto a bill.

While the specter of approving a law and triggering a dramatic reaction from FEMA sounds far-fetched, similar acts have happened before. In 2006, FEMA warned New Jersey that the state was at risk of being suspended from the NFIP because state laws blocked towns from adopting stronger floodplain standards than the state already had adopted.

In 2006, Mississippi, under pressure from homeowners, passed a law that meant the owners of hunting and fishing cabins did not have to elevate their structures to meet flood requirements. Following a major flood in 2011, FEMA found out about the laws and ordered the state to make changes or have its participation in the NFIP revoked, said Al Goodman, a private consultant and former Mississippi State Floodplain Manager. Mississippi's legislature rescinded the law last year, Goodman said.

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