A newly engineered stormwater project to relieve flooding on Front Street will mean Alachua Street access to the riverfront will be open to traffic by the end of the year, city officials told the city commission Tuesday night.
Utilities Director Andre Desilet detailed the change from installing a pumping station to deal with floodwaters to an infiltration system that will improve drainage with the rehabilitation of underground pipes currently in place.
The change was necessitated when estimated costs for the pumping station ballooned from $1.89 million in 2021 to $7.37 million earlier this year. The major costs were replacing the existing drainage pipes, which required boring under the existing railroad tracks, Desilet said.
The infiltration system will repair and upgrade the existing drainage system that runs the entire block of Alachua Street, east to Second Street. According to Desilet, the project should be completed by Oct. 25. "With this project we're confident we'll be able to address the flooding issues," Desilet told commissioners.
Desilet said the city "will have to pivot" from the original design.
The city will use cured in place, fiberglass liners to be installed inside the deteriorating drainage pipes. A cured-in-place fiberglass liner rehabilitates a stormwater drainage pipe by relining it with a durable, corrosion-resistant material, effectively creating a new pipe that addresses structural issues and improves long-term performance without the need for extensive excavation or replacement. By creating a smooth, new interior surface, the liners will improve the hydraulic performance of the pipes, allowing for better flow of stormwater.
The downside of the new design is that no pumping station will be in place to deal with surging flood waters that could potentially overwhelm the drainage capacity of the rehabilitated pipes.
"The idea behind the pump station was building for the future," Desilet said. "It was designed to work hand in hand with the waterfront flood protection. You could pump out the stormwater no matter what the tidal conditions were on the other side."
He said the revised system will require the city to manually pump out any stormwater that is trapped behind the flood protection wall. "For a non-surge situation, this (drainage system) will serve our needs," Desilet said.
Later in the meeting, the city commission approved $955,000 for construction of the railroad crossing to connect Alachua Street with Front Street.
"The scope of this project involves lighting, signaling, and of course the (railroad) crossing that would go in place at Alachua," said Interim City Manager Jeremiah Glisson. "Our schedule is to have Alachua open by the end of this year. This is a big piece of that."