Drought conditions in the upper Missouri River basin have expanded and are intensifying. The drought has reduced inflows to the Missouri River Mainstem Reservoir System, causing the Army Corps of Engineers to slightly reduce releases from Gavins Point Dam on the South Dakota-Nebraska border.
The total amount of water stored in the reservoir system is nearing its annual peak. Water stored in the annual flood control pool will be used this year for the authorized purposes, including hydropower, irrigation, water supply, water quality control, recreation, and fish and wildlife and navigation.
The Corps is now forecasting the total 2017 runoff in the Missouri River Basin above Sioux City will be 28.5 million acre feet (MAF) – 113 percent of the average of 25.3 MAF. An acre foot of water is the amount needed to cover an acre of land one foot deep. Runoff from the melting mountain snowpack is complete and inflows to the reservoirs are now declining.
Based on the amount of water stored in the reservoir system on July 1, the Corps will continue to provide for full-service, full-season flow support for navigation through at least November. Full-service flow support provides a 9-foot-deep by 300-foot-wide navigation channel from Sioux City to the mouth of the river near St. Louis.
Climatologists in the northern plains say this drought is similar to droughts in 1936 and 1988. It’s the worst drought some areas have experienced since 2006. Areas in northeastern Montana are the driest in recorded history. This year’s drought conditions have been exacerbated by high winds and hot temperatures. Many crops have failed or are maturing much faster than average and the crops are below average in development, which will impact yield.
For many areas of the upper basin, this drought started last fall. Many farmers and ranchers are culling their herds due to the lack of grass and because their stock dams have low and/or have poor water quality for livestock. Forecasters say the drought conditions are very serious now and may get worse before they get better.