FEMA proposes changes for floodplain maps

This entry was posted Monday, 7 January, 2013 at 2:52 pm

This article from the News Journal (Gannett) delawareonline.com

New maps reflect greater flood threat

Written by Jeff Montgomery and Molly Murray The News Journal; Jan. 06
Several times a day lately, Sussex County official Jeff Shockley finds himself plunging into the fine points of flood plains, prompted by calls from residents anxious about big storms and bigger insurance bills.

“There’s been much more interest in the past couple of years, and I think that it’s due to the storms that have hit and missed all around us,” Shockley said. “I get several calls a day from homeowners wanting to know if their property is close to a flood plain, how close they are to a body of water.”

The latest surge in interest has coincided with the arrival of new Federal Emergency Management Agency flood insurance boundary maps, slated for public review in coming months. Driving the map revisions, federal and state officials said, is a need to improve badly outdated risk boundaries, reset minimum building heights and better inform residents and agencies about insurance and planning needs.

In tidal areas, the updates also reflect sea-level rise threats certain to grow in coming decades, officials have said.

The new flood-hazard outlooks are based on expected flooding during present-day storms with a 1 in 100 chance of happening. Those water levels could become everyday events by the end of the century, scientists say, if current sea-level rise scenarios are realized.

“There’s talk about sea-level rise and the effect it’s going to have on us,” Shockley said. “It’s definitely opening our eyes here, and we are more worried about the construction out there that’s being done and has been done.”

Draft maps already are in circulation for some nontidal areas in all three counties – from the Red Clay and Appoqunimink watersheds in New Castle County to upper reaches of the Nanticoke River in Sussex County.

Proposed new maps for coastal areas of Kent County and Sussex County are scheduled to go to public meetings early next year, with New Castle County maps to follow by spring.

Similar projects are under way around the nation, as FEMA works to comply with a congressional demand for updated and more precise National Flood Insurance Program maps.

The timing couldn’t be better for places like Dewey Beach. The town has been the beneficiary of millions of cubic yards of sand to build storm resiliency along its oceanfront, but its bayside suffered significant flooding during Superstorm Sandy.

And with seas rising, Mayor Diane Hanson said it is likely that flooding will only grow worse with time.

Even now, without a hurricane or nor’easter, the ends of some bayside streets routinely flood during high tides, she said.

What municipal officials are trying to determine is whether storm drains have collapsed or are now lower than sea level, making them less effective. The other possibility is that rising seas are beginning to cause more persistent flooding problems, she said.

“If it is sea level rise and not infrastructure, they’ll have to raise their houses up,” the mayor said. “We’ve got to deal with reality here. It saves their houses, but if there is an emergency, how are we going to get there?”

Results of the new mapping project are critical for land and building owners in all coastal and waterside areas. The maps also affect emergency planners and local governments.

FEMA and regulators use the maps to determine flood risk and to recommend minimum building elevations for new construction or substantial rebuilding of existing structures. Banks, mortgage companies and insurers use the same maps to set flood insurance rates.

In January, Hanson will ask the municipal planning commission to tackle guidelines for future construction. These guidelines would likely help homeowners plan for sea-level rise, she said.

The end result for all residents of the town could ultimately mean lower flood insurance premiums, she said.

“Ever since Katrina, they have been skyrocketing,” she said.

Assessing threats Delaware’s Department of Natural Resources and Environmental Control already has sponsored two well-attended meetings for Red Clay and Appoquinimink watershed residents in New Castle County, but public awareness remains spotty statewide.

South of Milford, Ashley R. Malandrino said that she was unaware of the new map or it’s potential affect on her Cedar Creek Landing neighborhood, which lies west of Del. 1.

FEMA’s draft map raises the recommended first-floor elevation in Malandrino’s part of the neighborhood by a foot, to 10 feet above sea level – despite its considerable distance from the bay. Existing buildings are unaffected by the requirement, unless large-scale reconstruction or replacements are involved.

“I haven’t been following it,” Malandrino said. “No one here has been affected by flooding. They say it’s a flood zone, but it doesn’t come up that high.”

At least not yet.

About 5 miles of farmland, marsh and sparsely developed property separates Cedar Creek Landing from Delaware Bay. But the subdivision gets its name from the nearby tidal waterway that ebbs and flows through multiple direct and indirect bay connections.

High tides and surges find their way deep inland by way of a regular inlet north of Slaughter Beach, as well as several ever-widening connections with tidal marshland at Prime Hook National Wildlife Refuge.

Malandrino said Sussex County did require the building’s first occupied floor to be raised by several concrete blocks at the time of its construction to meet the 9 foot “base flood elevation” currently used by FEMA, insurers and local governments.

“I will admit that when it rains, our ground can get pretty squishy,” Malandrino said. “During that storm [Sandy], I was walking in from my backyard and my foot sank in shin deep.”

In tidal areas, FEMA’s Delaware maps will for the first time identify “limit of moderate wave action” boundaries, the farthest inland point where both flooding and waves of 1.5 feet or more are likely during major storms.

Present-day maps take waves fully into account only in so-called V-zones, or “coastal high hazard” areas, where waves of 3 feet or more are likely.

The new “LiMWA” classification emerged after FEMA officials noted that waves of 1.5-3 feet also caused major damage during Hurricane Katrina’s crossing of the Gulf Coast. Federal officials plan to encourage voluntary local government use of the same building restrictions for LiMWA property as now apply to the most tightly restricted coastal high hazard areas.

“It’s not a huge area, but it runs up and down the coast,” Shockley said. “I think it would be a great idea to incorporate that into our maps. We would have to run it through the County Council to have it adopted into our [flood plain] ordinance.”

In Joy Beach, an edge-of-the-water community on the west side of north Rehoboth Bay, longtime resident Joseph A. Faulkner said he had yet to hear about FEMA’s proposed maps or the reason his home was drawn inside the LiMWA area. Current flood rules, he said, already have increased the cost of life on the bay, from high insurance rates to a requirement to raise an addition on his house a foot higher than the rest of the original structure.

“We’ve never had any water inside our house or garage, but our community certainly has had water come in,” Faulkner said. “We get some pretty good storms here.”

Necessary updates

New Jersey is well along with a similar FEMA map update, but that process was interrupted by Superstorm Sandy – with FEMA determining that “the known flood risk has changed” as a result of tidal surges and water levels witnessed during that late October disaster.

Agency officials rushed out “advisory” flood boundary maps recently “to show a more current picture of flood risk” when issuing rebuilding guidance. Flood heights were boosted in some areas by as much as five feet.

In Delaware, more than 25,000 flood insurance policies are currently in effect around the state, although tens of thousands more inside flood plains are eligible but go without.

“I really think that property owners are going to be better served by these maps, because they accurately show the parts of the property that are flood prone,” said Michael S. Powell, program manager for DNREC.

Some Delaware maps now in effect are based on decades-old data, Powell said, while others are being amended to reflect a recent Army Corps of Engineers study of flood potential wave heights in the Chesapeake Bay, Delaware Bay and Atlantic coast of the Delmarva Peninsula.

The new maps make a wide range of changes in the boundaries and classifications of flood zones and the estimated “base flood elevations” of property – the assumed height of water during the peak of a “100-year storm,” or a storm with a 1 percent chance of occurring in any year.

Use of aerial land-mapping radar during the last decade has revolutionized flood plain studies, Powell pointed out, allowing more-detailed assessment of flood hazards and consequences that often were crudely estimated in the past.

In some noncoastal areas, Powell said, “there were watersheds that had never had a flood plain study done, even though FEMA had mapped a flood plain.

“They were horrendous. They were taking farms that had high ground into the flood plain, but there was no significant risk.”

Crude maps often put the expense and burden on property owners to sort out actual risks when seeking permits or insurance, Powell noted.

In other areas, such as portions of Stein Highway in Seaford, current flood plain maps omit large tracts of land regularly hit by flooding along tributaries of the Nanticoke River.

High stakes

Although FEMA has taken Superstorm Sandy’s high-water marks into account for New Jersey’s map update, Delaware narrowly missed what officials have said would have been a devastating blow. Without clear proof of higher risks, flood plain map development will go forward in Kent County and Sussex County without midcourse changes, Powell said.

“We do not believe that’s going to happen in Delaware, because the hurricane in Delaware didn’t show any area where the maps are just blatantly insufficient,” Powell said. “If the storm had taken some of the tracks that we heard it might take, like coming ashore on Delmarva, we would have had an unimaginably different concern.”

Yet DNREC Secretary Collin P. O’Mara said climate change and sea-level rise make it more likely that flood insurance maps will need revision more frequently than the five- to 10-year schedule now contemplated by FEMA.

Scientists have estimated that sea levels worldwide will increase at an accelerating rate in coming years because of global warming, rising by 5 to 6.5 feet before the end of the century. That rise could permanently flood as much as 11 percent of Sussex County.

FEMA’s new maps give a hint of the stakes.

Along the heavily developed Long Neck peninsula, west of the Indian River Inlet, new water-level and wave estimates show that an expanse of wave-tossed water up to a half-mile would isolate the easternmost third of the area in the event of a major hurricane or storm.

By 2100, that would become an everyday occurrence, based on worst-case forecasts for global warming and sea-level rise.

In places like Dewey Beach, which front the ocean but back up to Rehoboth Bay, there is the potential of flooding from both the ocean and the bay – a destructive combination that occurred during the March Storm of 1962 and the Jan. 4 Storm of 1992. Sandy caused extensive flooding and damage on the bayside, even though oceanfront buildings were largely spared.

To the west of the Indian River Bay at Oak Orchard, some homes sit on a bluff above the river, but others, like the apartment building where Richard Dondarski once lived, experienced flooding with several inches of water.

“I moved out because of Sandy,” Dondarski said.

A chef at the Serendipity Restuarant nearby, Dondarski said the business had three to four inches of water inside but was fine because the owners kept coming in to check on it and sweep the water out.

Up the road, as the ground rises higher above the river, Dan Lawruk, said he has had no issues with flooding – even with Sandy.

His home is elevated three cinder blocks high above the ground, he said.

But sometimes it is the unexpected storm with just the right wind that can catch you by surprise, he said.

“Worst I remember was a nor’easter two years ago,” he said. “They [the news media] didn’t even cover that storm.”

Contact Jeff Montgomery at 678-4277 or jmontgomery@delawareonline.com.

Contact Molly Murray at 463-3334 or mmurray@delawareonline.com.