Sunday, September 15, 2024

NCDOT releases sea level rise assessment for Cape Fear Crossing

At just 1-foot sea level rise, large swaths of land between New Hanover and Brunswick County would be underwater, according to a new NCDOT sea level rise report for Cape Fear Crossing.

NCDOT's 81-year-period report shows large areas of land inundated with water at just one-foot of sea level rise. (Port City Daily map/Courtesy NCDOT)
NCDOT’s 81-year-period report shows large areas of land inundated with water at just one-foot of sea level rise. (Port City Daily map/Courtesy NCDOT)

SOUTHEASTERN, N.C. — When planning a $1 billion infrastructure project, the North Carolina Department of Transportation needs to make sure its new asset won’t be under water.

North Carolina Department of Transportation released its 2019 Sea Level Rise Analysis report on its Cape Fear Crossing project last week. The report, which factors in federal tide gauge projects, predicts potential sea level rise scenarios over an 81-year-period.

Related: Brunswick County eliminated plans to address rising sea levels. Apparently, no one knows why

According to the report, Cape Fear Crossing won’t reach the design stage until 2040. That will come 20 years after the timeline for finalizing the department’s record of decision — determining where exactly the billion bridge will go — which is slated for next summer.

The data

The report considered the six routes North Carolina Department of Transportation (NCDOT) has remaining. One route, Alternative V, was recently ruled out as a viable option by the Federal Highway Administration because of its adverse impacts on the Wilmington historic district. However, the alternative is still included in NCDOT’s recent report.

Weighing tide gauge projections, calculated by the U.S. Army Corps of Engineers and National Oceanic and Atmospheric Administration, the report shows alternatives that border the Cape Fear River, Brunswick River, Town Creek, and Alligator Creek are vulnerable to inundation.

Catch up on Port City Daily’s recent series on the project: NCDOT can’t stop development and Brunswick and Leland are one step removed from a seat at the table 

Projected sea level information will be used by the department to inform the department’s height considerations for the new infrastructure.

Route V – in the bottom right – has been ruled out. The NCDOT has now assessed the threat posed by potential sea-level rise to the other five routes. (Port City Daily/Courtesy North Carolina Department of Transportation)

The report considered three risk scenarios: low, at 0-foot sea level rise; intermediate, at 1-foot sea level rise; and high, at 5-foot sea level rise.

At the lowest risk level, with no sea level change by 2100, 1.3 miles of Alternative V, the most innundated option, will be under water. About .1-miles of Alternatives B, Q and T would be inundated at this scenario.

In the highest risk scenario, nearly 6 miles of Alternative V would be inundated. Under the same scenario, about one half-mile of Alternatives B, Q and T would be impacted. Alternatives MA and NA, the longest routes, would be slightly more innundated than B,Q and T, and far less innundated than Alternative V. (View the full comparison below). 

Notably, the report cites the area surrounding existing interchanges on Eagle Island as most at-risk. “This large portion of land is likely to be completely underwater by 2100,” the report states.

A draft environmental impact statement is anticipated in the coming days. NCDOT encourages area residents with public comments and concerns are encouraged to redirect their input to the soon-to-be-announced public hearing in April. If comments cannot be held until the April hearing, NCDOT would prefer comments be sent to capefear@ncdot.gov. Learn more about the project here.

Read part one and part two of NCDOT’s sea level rise report.

Sea Level Rise Analysis by Johanna Ferebee on Scribd


Send tips and comments to Johanna Ferebee at johanna@localvoicemedia.com

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