The initial estimate for a new pedestrian bridge over the Arkansas River in midtown Tulsa is $25 million to $30 million, but the city has only $23.2 million left to build it.
The initial budget for the bridge was $24.5 million, which voters approved in the Vision sales tax renewal, and the City of Tulsa has spent around $1.3 million on design work. Chief of Community Development and Policy Nick Doctor said that’s not a problem. There are a lot of details to work out, as the estimate is based on a conceptual design.
"The materials that you use, the way that you construct that bridge and the kind of details that they'll be able to develop as they get closer to 60 percent design, which is really where you have harder cost numbers, that allows you to work that number to your budget," Doctor said. "So, this is a standard part of any construction process."
The new bridge will accompany the Zink Lake low-water dam. It will replace a repurposed railroad bridge that has stood for more than 100 years.
Mayor G.T. Bynum called for bridge design submissions in March. A selection committee chose the winning design, Gateway Bridge by Michael Van Valkenburgh Associates, in June out of more than 200 ideas.
Doctor said the project has several built-in opportunities for review.
"This is the first check-in that we've seen, in terms of cost and budget. The next one will be when we get to 60 percent design this spring, and that will provide more firm cost estimates," Doctor said.
Bynum asked architects for two versions of the bridge: a simpler one costing $24.5 million and one costing $35 million.
"Adequate shade and seating and those kind of components on the bridge, those are the extra amenities that will make it spectacular, but we're going to have a world-class bridge at both of those cost points," Doctor said. "And we'll have the resources and the information we need to get to that higher bridge once the designs are finalized."
Bynum said in March the city would pursue some private funding for the bridge if needed.