City Officials Consider Changing Tulsa's Flood Standards

Mar 10, 2014

A flood the size of the one Tulsa experienced in 1986 would likely cause sewer backup into the area A Gathering Place is being built at, shown by the light brown area around 31st Street. Tulsa's current flood standard is for a flood with a 1 percent chance of happening in a given year. That floodplain is shown in blue.
Credit Engineering Services / City of Tulsa

Tulsa city officials have started a discussion on changing Arkansas River flood regulations.

Tulsa’s current standard is construction must be 1 foot above the level of a flood with a 1 percent chance of happening any given year. The city could instead base the standard on the 1986 flood, which was 50 percent larger.

"You're going to get a flood that's going to flood somebody, even when we do the 100-year plus a foot," City Engineer Paul Zachary said. "If we get another 15-inch rain like what we did in 1984, there's going to be some structures that are going to get flooded. But it's just at what point do you draw that line of protection?"

More than 3,500 acres outside the floodplain the current standard is based on were affected by the 1986 flood.

Those stricter standards could affect the Gathering Place project. Zachary said there's a significant difference in the two standards right where the park will be built.

"In between 31st Street and the pedestrian bridge, the regulatory elevations would increase, roughly, just a little bit over 5 feet," Zachary said. "That's going to impact some buildings, and we just need to get into that detail with them."

Jenks is the only community along the river using the stricter regulations right now. They call for construction to be at least one foot above the level recorded for the river’s 1986 flood, the same regulation Tulsa is considering.