- Associated Press - Friday, October 31, 2014

New York City finished a $138 million reconstruction of an 87-year-old dam in its upstate watershed begun amid fears that a massive storm could cause a breach and wash away rural communities downstream.

Work on the 2,024-foot-long Gilboa Dam being unveiled Friday included replacement of the old bluestone face with poured concrete and an inspection gallery running along the dam’s length. Work started on Gilboa after inspections revealed the dam could fail under extreme stress, raising alarms among the roughly 8,000 people living in the downstream towns and villages east of Albany.

“The dam itself is going to meet all modern safety standards for a new dam. It’s going to be able to withstand the probable maximum flood,” said Paul Rush, deputy commissioner of the city Department of Environmental Protection.

The Gilboa Dam, completed in 1927, holds back the Schoharie Reservoir, the northernmost reservoir in the city’s sprawling upstate watershed. Water from the 19.2 billion-gallon reservoir flows more than 100 miles south to city faucets, largely through tunnels.

Safety checks begun after a 1996 flood revealed the dam’s possible problems and sparked interim repairs by the city while it prepared for the larger reconstruction project that was just completed.

“We’re happy to see the repairs, but ultimately I’m hopeful well never have to test the efficacy of the dam again,” said Middleburgh Mayor Matthew Avitabile, whose village is on the Schoharie Creek. “But ultimately down the road, we likely will.”

Officials have stressed the chances of the dam failing were close to zero, but an undercurrent of local fears came to a head when Tropical Storm Irene struck in 2011 and evacuation orders were issued after the DEP temporarily lost contact with the dam’s sensors. Eight feet of water went over the spillway and there was heavy damage downstream, but the dam held.

Avitabile added that there are still local concerns about the sort of flooding that devastated the valley after Irene. Rush said the city is committed to doing all it can to reduce flooding, though they are limited in what they can do during massive storms.

The dam work is part of a $400 million project that also will create a permanent release tunnel and site restoration. All work is expected to be complete by 2020.

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