I, for one, had not been able to clearly comprehend the references made in relationship to the amount of water that roared down the Missouri River i.e. “CFS” (cubic feet/second). I assembled some numbers so I could better understand and summed up my thoughts regarding the recent flooding.
Mother Nature dropped a significant amount of snow in eastern South Dakota, western Iowa and eastern Nebraska during the 2018/2019 winter season. I’m definitely not an expert, but I would have thought the Army Corps of Engineers would have appropriately forecasted and planned for excess March/April storage in the dams so as to reduce the potential for flood damage in the Missouri River basin in 2019.
The Missouri River was running, in my opinion, at low levels in the months of January and February 2019. Especially low, in my opinion, versus the record snow levels received down river from the Gavins Point Dam i.e. snowfall from Omaha/Council Bluffs south into Missouri.
Again, not an expert, but I would have thought the Missouri River managed dam storage space would have been capable of handling an unexpected surge. An unexpected surge such as the Spencer Dam breach. … Shouldn’t each Missouri river dam be managed to have room for excess capacity over forecasted needs?
Considering we are dealing with Mother Nature, what would be a good rule of thumb for excess storage capacity versus forecast? Possibly say plus or minus 10, 20 or 30 percent?
Its amazing, the magnitude when you do the numbers. The discharge from Gavins Point Dam in the 72 hours from 12 a.m. Thursday morning, March 14, until Saturday night, March 16, at midnight totaled in excess of plus or minus 140 billion gallons. Army Corps of Engineers released one huge, gigantic rolling wall of water. The three-day dam release on its own being a plus or minus 500,000 acre feet wall of force as it moved down river in 72 hours, then you need to add the uncontrollable snow melt. Look at the numbers, and in brief, the Army Corps of Engineers emptied the Gavins Point completely in a 72-hour period.
So with the above said, and with the old adage “I don’t know what I don’t know,” my understanding is that flood control was why the Missouri River dam system was built in the first place.
Dakota Dunes, S.D.