A forecast for potential major flooding rain from the National Weather Service due to tropical depression Cristobal as the U.S. Army Corps of Engineers on their toes for flood in the White River Basin.The Corps says it is prepared to respond as Cristobal draws near the basin weeks after spillway releases began on Bull Shoals, Norfork, Beaver and Table Rock dams. Those releases ended last week after the reservoirs were lowed by one foot from the top of flood pool, the Corps adds.
“The five White River Reservoirs are already high into their flood storage pools from heavy repeated spring rains,” says Mike Biggs, the Little Rock District’s Chief of Hydraulics and Technical Services Branch. “We see Cristobal coming and are prepared to capture as much rainfall runoff as possible. If rainfall runoff exceed a reservoir’s storage capacity, we’ll go into surcharge operations.”
The Corps says dam operations during a rainstorm will be based on rain that has fallen and can be measured. Rainfall forecasts are not accurate enough to base operational decisions on.
“Because rainfall forecasts are inaccurate, pre-releasing would put downstream users at risk if rain developed below the dam, instead of upstream,” says Biggs.
Rainfall amounts in the White River Basin are just above 140 percent of normal for the year. These totals make the spring of 2020 one of the wettest on record. The Corps is advising areas downstream of the dams to begin assessing their respective plans and to begin taking the proper precautions. Landowners with belongings near the river’s edge should also begin making plans for high water.
Because of uncertainty in weather forecasts, releases will be made in response to the on-the-ground rainfall to best minimize flood damages. The Corps will try to give as much notice as they can before surcharge releases are required.
The Water Management staff has been and will continue to be engaged and proactive in responding to the conditions.