by Bob Grawey
For residents along Otsego Creek, 2011 is the first time in many years they have not had to contend with spring flooding.
That is due to measures Otsego officials took in February to clean out the creek at 90th Street and a section going north approximately a quarter mile.
In times past ice would dam up in layers at the box culvert going under 90th Street, city engineer Ron Wagner explains.
This year just a small portion of the top of the culvert remained open.
When that happens, Wagner says the creek begins backing up to the point of redirecting itself.
In some places the redirected water has turned city property into wetland.
Redirected water flow from Otsego Creek has also flowed over 90th Street farther to the east, prompting signage cautioning motorists of potential problems driving through the water.
One problem created by the redirected water flow is that when it does join the creek again farther down, it deposits sediment it has picked up along the way.
Wagner says Otsego public works crews had to dredge the creek so its original water flow could be restored.
“We took soil borings to tell us where the original creek beds and banks used to be. The types of soils can tell you a lot,” Wagner says. “This section (of the creek) probably hasn’t been cleaned out for at least 30 years or more. In some places large trees have grown up in what should be the middle of the creek.”
Otsego Public Works Supervisor Brad Belair estimates his crews removed 500–700 cubic yards of sediment from the creek, anywhere from 2.5–3 feet deep in places.
Other sections of Otsego Creek have been cleaned out in past years, Wagner says, including fallen trees and other debris. The sediment build-up has been the real culprit for flooding, though.
Wagner says approximately a third of Otsego drains into the Otsego Creek. The engineer adds 25 percent of Albertville drains into the creek as well, giving it more than it could handle.
Now, however, since the creek has been cleaned out and dredged, it seems to be flowing and flooding has not been an issue this year.
The cost to clean the creek this year, according to Belair, is approximately $40,000.
Taxpayers are not billed for the work, as the funds come from developers’ fees already paid to the city.
Wagner says Otsego Creek will not need major cleaning or dredging for another four or five years.