Lock and Dam in Hastings prepares for flood; forecast is 18.9 feet by the end of the month
According to National Weather Service forecasts, the Mississippi River is expected to cross into the major flooding stage about midnight, March 26. As of 6 a.m. March 25, the river was at 13.72 feet. The latest predictions say the river will reach 18.9 feet on March 31.
At that height, portions of Lock and Dam Road will be under water, and those who work at the lock and dam will have to use an alternate route to get to work.
There are two options available, said lockmaster Mike DeRusha. Primary access will be via the city's paved bike trail over the Lake Rebecca levy. The Army Corps of Engineers has already come to an agreement with the city that gives the Corps' company vehicle access even after the city closes the trail to the public.
"The City of Hastings has been a great partner with us," DeRusha said.
The bike path floods at about 27 feet. The NWS is predicting a 50 percent chance the flood will crest at 24.5 feet. If the trail were to flood, the Corps' only other way to access the site is by using an airboat.
Much has to happen around Lock and Dam No. 2 before the flood reaches Hastings. Local staff have been instructed to protect the site up to an elevation of 28 feet. Already, staff there are filling thousands of sandbags to protect buildings and machinery that could be damaged. About 6,500 sandbags were filled last week already.
"And we're going to need more," DeRusha said.
A major concern is the lock machinery housed on the river. The Corps is using portable plastic barriers - which were intended to be used as anti-terrorism barriers - to help protect the equipment. Weighing only about 100 pounds empty, the barriers have been filled with roughly 100 gallons of water and bolstered on both sides with sand bags. The barriers' primary purpose is to deflect flood debris away from the equipment.
Also to keep debris from piling up and causing damage, the hand railings along the lock and dam walkways will be removed.
Sandbags and barriers are being put in place elsewhere on the property as well. Perhaps most noticeable is a long line of sandbags along one edge of the parking lot that will keep any water from Lake Rebecca out of the parking lot.
Besides protecting ground resources, the Corps is trying to reduce the chances higher water levels by keeping ice dams from building up in the river. Ice sheets are still breaking up in Spring Lake. Workers can adjust the 19 gates in the dam to allow ice sheets to pass through, DeRusha explained. Often, the force of the water breaks up the ice sheets in the process. For now, the Corps has to maintain a certain range of water levels in the pool above the lock and dam. Once the water rises high enough, all the gates will be opened to allow the maximum amount of water through.