The city of Wilmington plans to apply for nearly $20 million in federal grant funding to help pay for the replacement of two bridges – one on Fourth Street and the other on Pine Grove Drive.

The Wilmington City Council on Tuesday unanimously approved a resolution authorizing the city’s application for funding from the U.S. Department of Transportation and Federal Highway Administration’s Bridge Investment Program.  While both the Fourth Street and Pine Grove Drive bridges are currently rated in fair condition, they are expected to fall into poor condition within the next three years, according to agenda documents.

On Fourth Street, the existing 150-foot-long, three-span bridge was built in 1950. It was designed with a load rate of 25 tons, but, since 2016, the loading capacity has been steadily restricted. 

Today, the load-bearing capacity is 10 tons, which means the bridge can no longer accommodate buses and certain emergency response vehicles, Denise Freund, the city’s assistant director of engineering, told the council on Tuesday.

“Buses that come out of the WAVE transit facility cannot turn left and go across the Fourth Street bridge,” she said. “They need to reroute and go around that bridge.”

City staff worked with consultants to determine the best design approach for a replacement. 

They landed on a proposal that, like the existing bridge, has three spans and a similar elevation and low chord – the lowest point of the bridge structure. The bridge spans a corridor that's being looked at future passenger rail and a segment of the Downtown Trail. The city is coordinating the bridge replacement with these efforts, Freund said.

Replacing the Fourth Street bridge has an estimated cost of approximately $11.9 million, Freund said. The city plans to apply for grant funding to cover 80% of that cost or approximately $9.5 million. A local match of 20% or approximately $2.4 million would cover the full cost.

The city’s request for federal grant funding will also include money to replace the Pine Grove Drive bridge. The 60-foot-long bridge is connected to a causeway that spans coastal wetlands to its north and south. The bridge, which was built in 1976, is supported by wooden piles and abutments. 

“High traffic volumes and deterioration of the substructure has degraded the bridge over time. It is anticipated that continued deterioration will result in future load restrictions,” according to the resolution approved by the city council.

The bridge provides a key north-south corridor within the city and is “essential to provide emergency services access” for a nearby fire and EMS station, the resolution states.

Freund presented city council members with three potential design alternatives. Two of the alternatives would replace the bridge at an elevation similar to the existing bridge, but one option includes a separate multi-use path crossing while the other does not.

The third option, which is recommended by city staff, would extend the length of the bridge to 650 feet, replacing the existing causeway segments. The bridge would accommodate a multiuse path, provide more clearance for recreational boating and add resiliency by addressing concerns about future sea level rise, Freund said. 

“With the removal of the causeway under the bridge, we can allow those wetlands to restore within the areas where the causeway currently exists,” she added.

The city plans to include a funding request for that third option in its grant application. It's expected to cost approximately $12.8 million with the city requesting 80% of the cost or about $10.3 million in federal funding. A local 20% match could cost the city approximately $2.6 million.

City staff plan to hold a pop-up event on Oct. 16 from 4 p.m. to 7 p.m. at the Wilmington Municipal Golf Course at 311 Donald Ross Drive to collect public input on the Pine Grove Drive bridge replacement. An online survey is also available.

City staff plan to finalize a draft of the grant in mid-October and submit it no later than Nov. 1. Applications are evaluated on various factors, including state of good repair, safety and mobility, technical feasibility, innovation and benefit-cost analysis, according to Freund.