Last week’s news that the long-anticipated demolition of the pedestrian bridge over the Arkansas River had begun was a reminder that something is going up in the river, too.
And it’s right next door. The nearly $50 million overhaul of Zink Dam is underway and on track to be completed in the summer of 2023.
“We’re building the west half out, and by no later than October, we will be switching over to building onto the east side of the river,” said City Engineer Paul Zachary. “And then we’ll be able to basically operate the west half of the dam during our construction.”
Water — in the form of rain in Kansas and releases from Keystone Dam — is the primary potential obstacle to getting the dam completed on schedule. If the coffer dams that protect workers are breached, or run over, by a high, fast-flowing river, work stops and time is lost.
“Losing a coffer dam could cost three weeks to a month, depending on how severe the washout is,” Zachary said.
After decades of talking about putting water in the river, Tulsa voters in 2016 approved $63 million for river-related improvements, including $48 million for bank stabilization and Zink Dam renovations and $15 million for the new pedestrian bridge, called the Gateway Bridge.
The old Zink Dam, built in 1982, was 1,030 feet long, 7 feet high and included three 5-foot-high, 50-foot-wide gates. The new dam will be 10 feet high with 15 gates of varying heights extending more than half the length of the dam.
“Right now out of 1,000-plus-foot of dam, we have about 150 feet of gates in it. When we get done, we’re going to have over 400 feet of full-height gates that can be dropped all the way to the river bottom,” Zachary said. “That is going to help us greatly with the sediment being trapped behind the dam. It’s going to allow us to have water go through there.
“It is just going to be such a better condition, not only for operating, but for (clearing) sediment, and allowing the fish passage to go through the dam.”
The new dam will also be safer than the old one. Thanks to a change in design, the new dam won’t have a dangerous undertow on the downstream side of the structure.
“Stair steps are being built to where as water comes over the dam or through some of the gates … the water will go down these stairs and drop back into the river, which totally eliminates that undertow where all too many times we heard of swift water rescues that our Fire Department’s having to do,” Zachary said.
The Zink Dam renovation and related work in the river was designed to provide a better natural habitat for wildlife, and a 1,050 recreational flume near the east bank of the river is being constructed for kayakers and surfers.
If all goes as planned, the Gateway Bridge will be completed at about the same time as the Zink Dam renovation. And Tulsans will finally have their long-awaited Zink Lake — stretching upstream to the Interstate 244 bridge — to enjoy.