DFM News' five part series on the potential impact of sea level rise in Delaware continues with Part III - the second stop on our county-by-county look at the issue, Kent County.
In Kent County, the community of Bowers Beach is a poster child for low-lying coastal settlements that have been living with coastal flooding for years, and expect to see more of it from future sea-level rise.
[caption id="attachment_12656" align="alignright" width="215" caption="Click here to view a slide show presentation of our visit to Bowers Beach shortly after Hurricane Irene."]
The former fishing port southeast of Dover is examining an outside consultant’s report which assessed its flooding problems and recommended changes designed to lessen the impact of flooding from spring tides, nor’easters and other storms, and the presumed effects of climate change and future sea-level rise.
The March 2011 report, prepared for DNREC by KCI Technologies Inc., called sea-level rise “an inescapable scenario that will plague the Town of Bowers Beach in the future” and which should be taken into account in the planning process.
But sea-level rise appears to be a distant possibility rather than a current reality, and is just one of a number of factors that the town must deal with in its efforts to revive its business district, said Mayor Ron Hunsicker.
The town, built on a neck of land between the Delaware Bay and two rivers, is working on the assumption that sea-level rise will happen, Hunsicker said, but the prospect is not dominating the planning process or the thoughts of the town’s 350 year-round residents.
“Do I take it seriously?” he said, referring to sea-level rise. “You can’t ignore it but I don’t lose any sleep over it. I don’t feel any sense of urgency.”
Amid the chronic flooding suffered by Bowers Beach, the mayor said there’s no clear sign that any of it has been caused by rising sea levels despite anecdotal reports from around the state that rising seas are already encroaching on farmland, eroding beaches and flooding marshes.
“I don’t see any significant impact of sea-level rise on our flooding problems here,” Hunsicker said in an interview.
That’s consistent with a statewide survey showing Kent County residents were the least likely to worry a breat deal or a moderate amount about sea-level rise, and the most likely to consider that it’s not at all a serious threat to the local economy or their property.
Statewide, sea-level rise ranked at the bottom of people’s concerns, identified by only 32 percent of respondents as something they were worried about, according to the DNREC survey of 1,505 people conducted in fall 2009 and released the following year.
In Bowers Beach, the “Final Drainage Report” shows how much worse recent storms and high tides would have been if the seas rose to the level predicted by DNREC over the coming century. If seas rose by 0.5 meter, the smallest increase projected by the agency, the water level in the Mother’s Day storm of 2008 – which generated 60 mph winds and 20-foot waves off some parts of the Delaware coast -- would have been about 1.5 feet higher than it was.
The high point of a spring tide on March 13, 2010 would have been more than twice as high if sea levels rose by 1.5 meters, the biggest increase in the DNREC scenario, the report said.
The town is “particularly vulnerable” to coastal storms and sea-level rise, according DNREC, which predicts the community will have to deal with stronger and more frequent storms, increased erosion, saltwater intrusion, and wetland loss as seas rise and the climate changes.
For now, Bowers Beach has its hands full dealing with nor’easters, which can dump up to four feet of water in some areas of the town, causing saltwater intrusion into water wells, closing businesses for weeks, eroding beaches and dunes, and damaging buildings and vehicles.
It is also threatened by spring tides which can result in foot-deep floods, overtopped boat ramps, and a sharp rise in the mosquito population.
The town’s vulnerability to such natural hazards is heightened by poorly maintained drains that clog with sediment and vegetation; the erosion of dunes that help to shield the town from the ocean; and the malfunction of tide-control valves, among other factors, the report said.
Recommended improvements include installing extra tide-control valves, repairing sea walls, realigning drains, and keeping drains free of debris. The work is estimated to cost $572,000 which Hunsicker hopes will be paid by a combination of state and federal funds.
While Mayor Hunsicker is reluctant to attribute his town’s flooding problems to sea-level rise, that’s the main reason for the shrinkage of Bombay Hook National Wildlife Refuge, some 25 miles to the north, according to refuge manager Michael Stroeh.
The 16,251-acre refuge that attracts hundreds of thousands of ducks, geese and shorebirds every winter has lost some 1,500 acres of its coastal marsh in the last 30 years, or 58 acres a year, a process that shows no sign of letting up.
The salt marshes are being replaced by mudflats and, increasingly, by open water, as the silt that traditionally replenishes and sustains the marsh drains out more quickly than it can be replaced by natural forces, Stroeh said.
The shrinkage of this national wildlife refuge can be traced in part to a system of man-made ditches that drain sediment from the marsh, and to an explosion in the number of wintering snow geese decimating the vegetation that helps to anchor the marsh.
But the main culprit is the ocean, which has risen 3 millimeters a year over the last century, and is gradually taking over one of Delaware’s natural treasures.
“The shoreline is retreating and the interior is drowning,” Stroeh said. “It’s getting to the point where we’ve got to start addressing these problems that are exacerbating the situation.”
With its rising sea levels, flooding, subsidence, and erosion, Bombay Hook could be a case study in coastal change that will help DNREC scientists manage sea-level rise statewide, according to the agency, which is working with refuge managers to analyze the situation.
“The drastic changes at Bombay Hook may be a harbinger of coast-wide habitat changes in the future,” DNREC said in an overview of its work on sea-level rise.
While there is no sign of recent acceleration in sea-level rise at Bombay Hook, managers there are taking the threat posed by the ocean more seriously than they did 10 years ago, and considering measures that might counteract the apparently inexorable rise of the sea, Stroeh said.
Despite the denials of some skeptics, there’s no doubt that sea-level rise is a fact, said Stroeh. “It’s well documented – the controversy is how bad it’s going to get.”
Next in the Rising Threat series: A look at the how the issue of rising sea levels is viewed in Sussex County.
Previously: Part I - Rising seas threaten Delaware coast, test policymakers.
Part II - City of New Castle plans dike repair to repel rising seas.
