August 14, 2013
In wake of flooding —
Detention basins sought
Officials examine drainage problems in Otter Creek watershed
With vast local flooding as a result of last week’s storm, officials are exploring what caused the water runoff problems in an attempt to better address the repeated overflowing of Otter Creek during storms.
Patrick Reidy, water quality specialist for the Cortland County Soil and Water Conservation District, said Monday that the nature of the storm lends itself to flash floods. About 3.5 inches of rainfall fell in less than three hours in certain parts of the county.
“So it was a very extreme event. If we had 3 inches in 24 hours, we probably wouldn’t have had flooding,” Reidy said. But with such a large amount of rainfall in such a short time-frame, the streams and creeks were not able to handle the great quantities of water.
Reidy advocates a comprehensive study of the drainage problems in the Otter Creek watershed to arrive at a mitigation plan for the flooding.
He said there are two ways to address the flooding problem: provide more detention basins like the berm in the city waterworks, or widen the streams to increase their capacity.
Providing more storage would slow the water down and increasing the capacity of the streambeds would help prevent overflowing.
Increasing the capacity of streams must be done carefully, Reidy said, since it could create problems elsewhere.
And improving the entire creek would be very expensive, potentially costing millions of dollars because of the necessary bridge replacements and taking of properties bordering the creek that would accompany such a plan.
Creating more storage basins might be the least disruptive choice because it would not have the same type of downstream impacts that increasing the creek’s capacity would have, he said.
City Department of Public Works Superintendent Chris Bistocchi agrees that adding detention basins is the best option. He said that adding detention basins in the rural areas outside of the city would help stem the flooding of Otter Creek in the city. It is not the number of basins that would have to be added, but their size, that would matter, he said.
Bistocchi said adding detention basins is definitely preferable to increasing the capacity of Otter Creek.
“Otter Creek cannot be made any larger without taking properties and at that point it’s going to cost the city quite a bit of money and people are not going to be in their homes,” Bistocchi said.
Reidy said a good candidate for a detention basin is on the south side of Bennie Road opposite Walmart. About 50 acre feet of storage could be provided there, he said, which would mean that across a 10 acre site the basin would be on average 5 feet deep.
Searching for more modest-sized sites for detention basins would require the correct topography, he said.
“You’d look for a relatively flat area uplands along one of the streams or tributaries that would lend itself to putting up some kind of berm or detention basin structure that you could store water and let it out slowly,” Reidy said.
Creating a detention basin could require state Department of Environmental Conservation permitting in the event that dam safety regulations must be followed. Wetland permitting would have to be done through the U.S. Army Corps of Engineers, he said.
But Cortlandville Town Supervisor Dick Tupper said “size and location” of a detention basin are key. Finding an area that will both work and not create problems elsewhere are important.
“These are very expensive. You don’t want to put one in and find out it’s not large enough or in the wrong spot,” Tupper said.
Tupper said the town highway superintendent studies the problem of flooding on an “ongoing basis” along with the county Highway Department.
He said the 100-year storms seem to be happening about every five years now.
In the meantime, city officials are taking measures to alleviate problems suffered by flood victims.
City Mayor Brian Tobin is urging residents to contact their insurance companies to see what their policy covers and also he wants residents to inform the city if they experienced flooding. This way city officials can be proactive in addressing future floods, he said.
The city is also providing waste bins near Beaudry Park and along the Maple Avenue area for people to dispose of their belongings that were damaged in the floods, such as moldy clothes and furniture. The bins will be available to residents until the end of the week and the city will arrange the dumping of the material.
The county Legislature’s Flooding Subcommittee is meeting Sept. 10 and Legislator Sandy Price (D-Harford and Virgil), who chairs the committee, said officials will take up the idea of creating more detention basins.
“The berm that was built in the city, there was much discussion in the Flooding Subcommittee years ago so yes, that would be an excellent place for it to start and hopefully some money can come to that,” Price said.
Price said applications would have to be made through the federal government for Federal Emergency Management Agency mitigation grant money and county Emergency Management Assistant Coordinator Brenda DeRusso will be on hand to give guidance on that application process.
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