OMAHA, Neb. (AP/KCAU) — The amount of water being released into the Missouri River from a dam on the Nebraska-South Dakota border is being decreased.
Officials said it’s because less water is expected to flow into the river this year, so the risk of a repeat of last year’s massive flooding along the river has been reduced.
The reduction is possible because the region received less precipitation than expected this spring and this summer is expected to be drier than normal.
The Corps now estimates that 31.2 million acre-feet (MAF), or 121% of the average, of water, will flow down the river this year. The average annual runoff for the upper basin is 25.8 MAF.
That’s roughly one million acre-feet lower than the previous forecast.
“The upper basin runoff forecast has been reduced by about 1 MAF due to the recent dry conditions as well as the National Weather Service’s climate outlook, which is indicating that the remainder of the summer will be warmer and drier than normal. However, the 2020 calendar year runoff forecast remains above average, mostly due to the very wet soil conditions during the early months of the year. Most of the mountain snowmelt runoff has entered the reservoir system. Remaining summer runoff will depend on rainfall events.”From John Remus, chief of the U.S. Army Corps of Engineers’ Missouri River Basin Water Management Division
“As a result of the reduced runoff forecast, we will reduce Gavins Point Dam releases to 30,000 CFS on July 7,” added Remus.
Officials said the soils continue to dry out in the upper Missouri River Basin due to the well-below normal precipitation and warmer-than-normal temperatures.
The drought conditions, based on the National Drought Mitigation Center Drought Monitor, have expanded across much of the western portion of the Missouri River Basin.
The Corps mentions the potential for localized flooding remains in the Missouri River Basin.
The flooding potential is higher in the lower basin from locally heavy rain on the many uncontrolled tributaries downstream of the Missouri River Mainstem Reservoir System.
“I continue to encourage all interested parties to remain aware of the current and forecast conditions by checking the Corps’ Missouri River Basin Water Management and the National Weather Service websites on a routine basis for the most up-to-date information,” said Remus.
As of Monday, the total volume of water stored in the System was 61.5 MAF, which is up 1.7 MAF since June 1, occupying 5.4 MAF of the System’s 16.3-MAF flood control zone.
The U.S. Army Corps of Engineers Reservoir Forecast for Gavins Point Dam:
- Average releases past month – 33,000 CFS
- Current release rate – 33,000 CFS (as of July 1)
- Forecast release rate – 30,000 CFS (month of July)
- End-of-June reservoir level – 1206.1 feet
- Forecast end-of-July reservoir level – 1206.0 feet
- Notes: Releases may be adjusted as necessary to offset tributary flows from heavy rain events.
The Corps said the forecast reservoir releases and elevations aren’t definitive and the additional precipitation, lack of precipitation, or other circumstances could cause adjustments to the reservoir release rates.
For more information on the decrease in releases from Gavins Point Dam, click here.