On May 28, the Oklahoma Department of Emergency Management published a map of the state, indicating that all 77 counties of the Sooner State are under a declared state of emergency. Following flooding, severe storms, tornadoes and extreme winds beginning in April, the state has been inundated with devastating weather events, with the potential for more on the horizon.
Heavy rainfalls across the state have tested upstream flood control structures, with maximum totals as high as 15 inches in the Arkansas River basin, and an average statewide rainfall of 10 inches for the month of May. Arkansas River flooding has put a good portion of the low-lying areas in Tulsa underwater, and the National Guard has been called out to patrol the river levee system due to breech concerns.
“The horrific flooding that Oklahoma has experienced over the last month reminds us our state has a long and dark history of weather extremes,” says Trey Lam, Executive Director of the Oklahoma Conservation Commission (OCC).
“During the decades of the 1920s through the 1940s, Oklahoma experienced major floods (with more than 50 percent of the flood plain inundated) at least twice a year,” Lam said. “Much in the same way they battled the Dust Bowl, conservation districts and the USDA Natural Resources Conservation Service (NRCS) planned and built 2,107 flood control dams to alleviate flooding.”
“Although over half these dams have exceeded their planned life, they continue to provide flood protection along with sediment and nutrient capture and public water supply,” Lam said. “It is our duty to maintain this flood protection system. We appreciate the commitment from the Oklahoma Legislature and our Congressional delegation to keeping our citizens safe.”
Last week, Governor Kevin Stitt signed into law the general appropriations bill for Fiscal Year 2020 (FY20). The FY20 Budget includes $1.5 million for rural dam improvement, which will go toward the operation and maintenance of flood control dams.
Oklahoma has 2,107 flood control dams protecting homes, businesses, roads, bridges and other infrastructure, as well as crops, farmland and ranch land. The Small Watershed Upstream Flood Control Dam program is managed cooperatively by conservation districts in the state, the OCC and the USDA NRCS.
An NRCS National Watershed Benefits computer model estimates the daily monetary benefits resulting from watershed projects for a specific storm. These benefits are essentially the damages that would have occurred from that storm had the dams not been built. The report detailed $16.5 million in monetary benefits resulting from the watershed projects in Oklahoma during the 24-hour period from 7 a.m. Monday, May 20 to 7 a.m. Tuesday, May 21. On an annual basis, the 2,107 Oklahoma Upstream Flood Control structures provide $96 million of benefits statewide.
“The watershed structures are doing their job,” NACD South Central Region Representative Keith Owen said. “The dams are preventing catastrophic flooding, damage to property and loss of life. Conservation district employees and OCC staff along with personnel from NRCS are constantly watching these valuable assets to the protection of Oklahoma’s infrastructure. With more rainy weather in the forecast, the state will rely on them to mitigate the flood waters to come.”