A new concrete bridge will replace the crumbling Lake Gerar Bridge, the Rehoboth Beach Board of Commissioners decided this week.

The commissioners selected a one-arch concrete bridge design, following an April 4 presentation on materials and structural designs by state engineer Allan Kercher of Kercher Engineering Inc.

Kercher explained the pros and cons of timber, concrete and steel bridges. “Overall we believe that concrete is the way to go,” Kercher said. Aside from construction costs, which are slightly higher, Kercher said concrete requires the least amount of maintenance, has a longer life expectancy and is the least likely to show structural deficiencies.

Kercher’s initial cost comparisons put a concrete bridge at about $1.7 million, slightly higher than the estimates for a steel bridge at $1.6 million or for a timber bridge at $1.5 million.

“I think these numbers are high, but I didn’t want to estimate too low,” Kercher said. He said the soil around the bridge is bad for building, making it more expensive to build the bridge foundation. “That’s part of the reason why the costs are as high as they are,” he said.

Rehoboth Beach Mayor Sam Cooper said concrete appeared to be the best option. Cooper, who initially estimated a new bridge could cost as much as $2 million, said funding is still up in the air but the city will be able to talk seriously about funding options once designs for the new bridge are in place. “We’re quickly reaching that point now,” Cooper said.

Kercher also presented design options for the bridge through a series of graphics illustrating bridges with one to three arches, a variety of styles for lights, railings and ways to incorporate sidewalks and bike paths. “There are endless options,” Kercher said. The concrete bridge can also be covered with either brick or stone. The commissioners all preferred a single-arch, flat bridge.

“The idea is to keep it somewhat muted,” said Commissioner Patrick Gossett, who preferred a flat bridge to a higher, rounder bridge. Commissioner Mark Aguirre said he thought the high arch was charming and made the structure look more like a footbridge.

“I would like to get the Aesthetic Committee involved,” said Aguirre. Commissioner Richard Sargent and Aguirre agreed the Aesthetics Committee for the Rehoboth Avenue Streetscape Improvement Project should provide input on design decisions. Cooper and the commissioners agreed it was important to keep the design consistent with the streetscape project.

“It’s a heavily traveled bridge,” said Commissioner Kathy McGuiness, who said a designated path for pedestrians is a priority. “A lot of people walk and ride bikes.” The commissioners agreed that walkways and the fishing pier should remain, even if they are incorporated into the bridge differently than they are today.

Cooper said construction on the replacement bridge could begin next fall, “but a lot of things still have to happen for that to fall in place.”