The best way to combat flooding in the Frederick Street area isn’t to straighten out the Copper Mine Brook’s meandering channel, as the city has long planned.
Instead, experts who are looking into the problem have determined that replacing the century-old bridge on Frederick Street would do more to relieve flooding.
As a result, city councilors recently backed a contractual change with the Cheshire-based Milone & MacBroom engineering consulting firm to switch its attention from redesigning the stream channel to coming up with a plan for a new bridge.
The Frederick Street Bridge is one of a dozen Connecticut spans that’s been rated in “criticial” condition and was closed for a month in 2007 for emergency repairs on its foundation so officials have long expected they would replace it.
Now, though, they’ve learned that putting up a wider, slightly higher span in its place is also the best thing they can do to combat flooding on the lower section of the Copper Mine Brook, which has had several serious floods in the past five years.
Large sections of the creek and its tributaries overflow during heavy rains, inundating basements, washing over streets and causing significant damage. Frederick Street has had to be evacuated at times because of the quantity of water.
Realigning the S-curve just north of the bridge, as the city had anticipated it would try, would not help with flooding and might even raise the water level behind the bridge, according to a January memorandum from Milone & MacBroom to a city engineer.
It isn’t clear just how much a new bridge would help with flood control either, but the consultants said it should provide some benefit.
However, they added in the memo, “the effectiveness of anything done at the crossing itself will be limited due to the tailwater effects of the Pequabuck River” just downstream.
What happens, in a nutshell, is that water pouring down the Copper Mine Brook during heavy rains runs smack into a swollen Pequabuck near Theis Precision Steel and begins to back up across Frederick Street and into homes.
There are many complicating factors, from poorly placed drains to small berms, but the problem that fundamentally afflicts the low-lying area is that there is nowhere for the water to go.
The change in the contract with Milone & MacBroom won’t cost taxpayers anything extra because it’s doing the same amount of work, just on something different than expected.
The firm is receiving more than $200,000 to study flood relief measures along the length of the brook. It issued a preliminary report several months ago.
Other flood control projects in the works
Stream channel improvements in Richard Court area
Construction of watershed storage along the brook
Contact Steve Collins at scollins@bristolpress.com
