SIOUX FALLS, S.D. (KELO) — Somewhere in the neighborhood of 1-2 million acre/feet of water is on its way through the Missouri River system as a result of the flooding on the Yellowstone River.
The reason that water is coming to the Missouri is because Yellowstone is one of many tributaries feeding into the Missouri. Any water that enters the Yellowstone will flow through South Dakota on its way to the Gulf of Mexico, which can be seen in this visualization via River Runner.
This is enough water to fill between 493,200 and 986,400 Olympic swimming pools, but according to Army Corps of Engineers Chief of Missouri River Basin Water Management John Remus, that’s only a drop in the bucket.
This is because the entire Missouri River reservoir system, running from Gavin’s Point Dam in Yankton to Ft. Peck in Montana, holds a total of around 72 million acres/feet of water. He says the reservoir system is working as it should, and can easily absorb the excess water from the Yellowstone.
In fact, South Dakotans will see little effect from the flooding. While the Garrison Dam up in North Dakota, Remus says the water will likely rise about 3-4 feet, though he says this should not present an issue for the area.
Meanwhile, further down in South Dakota, Lake Oahe will see a rise of less than a foot. At the end of the reservoir system at Lewis & Clark Lake, no noticeable rise in water level is expected.
With water levels in South Dakota’s reservoirs low this year due to drought, any extra water could be beneficial, but Remus cautions that the flood waters from Yellowstone will not be enough to replenish reservoirs like Oahe to their pre-drought levels.