Tuesday, March 21, 2023

How the Wilmington area deals with rising seas and an increasing number of floods

Wilmington's low-lying areas are prone to flooding; that situation is unlikely to improve as sea levels rise. This photo was taken last fall after Hurricane Matthew. (Port City Daily file photo / HANNAH LEYVA)
Wilmington’s low-lying areas are prone to flooding; that situation is unlikely to improve as sea levels rise. This photo was taken last fall after Hurricane Matthew. (Port City Daily file photo / HANNAH LEYVA)

WILMINGTON — The Port City was fortunate this year, as several powerful hurricanes missed southeastern North Carolina.

Hurricanes and powerful storms are of particular concern to Wilmington, as the city is one of several on the Atlantic coast that suffers from frequent flooding — even on a good day.  So-called “Sunny Day Flooding” has hit hardest in low-lying cities like Wilmington, Charleston and Norfolk.

According to research by the National Oceanic and Atmospheric Administration, rising sea levels magnifies tides and can cause damage without a drop of rain. So, add a weather system packing heavy rainfall or powerful storm surge, and those effects are magnified.

That threat has pushed cities like Norfolk to consider the impact of rising seas on the local economy. It’s also the reason Charleston has taken aggressive action, planning for increases of as much as 2 and a half feet in sea level over the next 50 years.

A much-maligned 2012 law in North Carolina essentially blocked state-level agencies from using predictive methods to determine the possible impact of rising sea levels. The initial draft of the law would have essentially gagged local and regional government from officially discussing some of the more pessimistic sea level estimates. However, the final version of the bill was altered and, while it continues to constrain coastal management and the state’s Department of Transportation, it does allow counties, towns and cities to pursue their own policies, studies and plans.

Here’s how governments and utilities in the Wilmington area are planning for potential increases in sea level.

Wilmington

Phil Prete was the Environmental Planner for City of Wilmington for 13 years, and helped direct the city’s response to rising sea levels.

“Probably the most important thing, the first thing, when it comes to planning is not to look the other way, to actually address sea level rise and plan for the future,” Prete said. “The next thing is to look to our neighbors. Hampton Roads, Norfolk, Charleston.”

Prete helped direct the city’s Community Resilience Pilot Project. The 2012-2013 project ultimately pulled in New Hanover County and the Cape Fear Public Utility Authority, and focused heavily on vulnerable infrastructure.

“I was pleasantly surprised with the outcome of that project. It was pretty much what I considered to be state of the art modeling at the time,” Prete said.

The project was focused of water and wastewater infrastructure, but has been used to model the impact on other infrastructure systems, including roads. However, the program only identified vulnerable areas; it wasn’t a formal plan for the city — and it didn’t bring up the crucial issue of funding.

Though Wilmington is at risk from flooding, Prete said the area hasn’t seen the same kind of aggressive action as in Norfolk or Charleston.

In part, that’s because of Wilmington’s geography, Prete said.

“We’re very lucky in Wilmington, in that the land in general rises pretty quickly up from the river. And the barrier islands provide protection for the coast,” Prete said.

But that doesn’t mean Wilmington is off the hook.

From the 2012-2013 pilot program study of sea level rise in Wilmington: potential flooding exacerbated by rising sea levels. (Port City Daily photo / COURTESY CITY OF WILMINGTON)
From the 2012-2013 pilot program study of sea level rise in Wilmington: potential flooding exacerbated by rising sea levels. (Port City Daily photo / COURTESY CITY OF WILMINGTON)

“The shoreline of the river is definitely vulnerable, as are the tidal waterways and the barrier islands – Wrightsville Beach, Carolina Beach – are definitely at risk,” Prete said. “We all know Water Street floods all the time, that’s the same kind of event that ultimately pushed Charleston to take action.”

That kind of action hasn’t happened in the Wilmington area, Prete said, adding that planning for rising sea levels means planning for 10, 50 or 100 years, a time frame politicians don’t always want to address.

“You don’t often see it until there’s something disastrous, a catastrophic flood, or the threat of one. So, there really aren’t any communities between Charleston and Norfolk that are taking aggressive action on this,” Prete said. “It’s always easy to kick the can down the road … it’s not a matter of political expediency. You have politicians serving two-year – or four-year – terms. If you’re talking about the next 100 years, well, that’s way past the end of your term, isn’t it?”

Prete retired from his position in Wilmington at the end of 2016. The environmental planning duties were divided up and assigned to other positions, according to Malissa Talbert, spokeswoman for the city. Talbert said there are no current plans to hire a new environmental planner.

New Hanover County

The county doesn’t have a full time environmental planer, but is instead guided by the Southeastern North Carolina Hazard Mitigation Plan. The five-year guideline is mandated by state law, and includes both county and municipal guidelines for dealing with a range of environmental issues, including flooding and rising sea levels.

The plan includes general policies, like “Discourage high intensity uses and large structures from being constructed within the 100-year floodplain (1 percent annual chance floodplain), erosion prone areas, and other locations susceptible to hurricane and flooding hazards.”

It also includes specific issues, like streets and neighborhoods prone to flooding, along with the county’s plans for addressing those issues. Weighing in at nearly 600 pages, the plan covers Brunswick, New Hanover and Pender counties. You can read the plan here.

Duke Progress

Duke Energy has sunk billions of dollars into preparing for rising sea levels, including initiatives like raising power stations on concrete platforms ahead of 100-year storm events. (Port City Daily photo / COURTESY ROBERT PARR)
Duke Energy has sunk billions of dollars into preparing for rising sea levels, including initiatives like raising power stations on concrete platforms ahead of 100-year storm events. (Port City Daily photo / COURTESY ROBERT PARR)

According to Meghan Miles, spokeswoman for Duke Energy, the company has launched a $13 billion, 10-year program. The initiative is based on the company’s own in-house data on rising sea levels and flood plains.

“We’ve been operating for a long time, and so we know which areas are impacted by storms,” Miles said.

The program includes efforts like putting vulnerable power lines underground, and elevating power stations on six to 10-feet concrete platforms.

“It’s a 10-year plan, so we’re thinking about flood events for the next decade.”

CFPUA

The Cape Fear Public Utility Authority took part in Wilmington’s Community Resilience Pilot Project, which focused heavily on water infrastructure; the project identified present and potential future vulnerabilities.

Eric Hatcher, CFPUA’s security and emergency manager, said it may have been initially unclear what the action the project would generate.

“It was a non-binding plan, not a budgeted plan of action,” Hatcher said. “There may have been some confusion about why we didn’t run out and tackle every problem.”

That doesn’t mean CFPUA is ignoring ris­­­­ing sea levels. According to Hatcher, CFPUA was faced with a host of infrastructure “at the end of its lifespan.” In replacing those facilities, Hatcher said new construction was engineered with long-term sea level rise in mind.

Imaging from CFPUA cameras sent through a waterline suffering partial collapse from the added weight from rising sea-levels. (Port City Daily photo / COURTESY CFPUA)
Imaging from CFPUA cameras sent through a waterline suffering partial collapse from the added weight from rising sea-levels. (Port City Daily photo / COURTESY CFPUA)

Rising sea levels also have some unexpected effects. One is additional pressure on lines running under bodies of water, including a major raw water line that travels under the Cape Fear River. CFPUA routinely sends cameras through these pipes to see if they are beginning to buckle under the increased pressure.

Another issue is what happens when flooding cuts out other utilities, like power. Hatcher pointed out that while CFPUA’s pumps are set on high ground, and have back-up generators, the authority didn’t initially have a way to secure fuel in an emergency — a lesson Hatcher said he learned from watching difficulties in the New York and New Jersey area after superstorm Sandy.

During that storm, Atlantic City and the low-lying areas of New York City experienced extreme flooding and severe infrastructure damage, in part due to lack of planning Hatcher said he wants the Wilmington area to avoid a similar fate.

“We know the sea levels are going to rise, we know what the effects will be, we aren’t waiting for it to happen,” Hatcher said.


Send comments and tips to Benjamin Schachtman at ben@localvoicemedia.com, @pcdben on Twitter, and (910) 538-2001.

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