Mad River Dam holds back near-record rainfall

WINSTED — It has been a wet and cool summer in the Northwest Corner. And while the season’s frequent heavy rains and thunderstorms have led to minor flooding in some areas and the occasional downed power line, so far the precipitation has not been steady enough to cause any major water damage.

“This was probably the second wettest July in about 70 years,� Dennis Schain, a spokesperson for the DEP (Department of Environmental Protection), said.

The record for rainfall in Connecticut in July is 11.25 inches. Schain said last month’s total amount of precipitation was just shy of that mark.

“But because the rain was spread out, it really hasn’t been an issue with major flooding,� he said.

Even if a significant multi-day rainfall event were to occur here, however, Winsted would be protected from the raging waters of a swollen Mad River by the dam that lies just south of the town’s border with Colebrook along Route 44.

The Mad River Dam, which was built by the Army Corps of Engineers after the flood of 1955, is managed and operated by the state Department of Environmental Protection. It was completed and went online as a flood control facility in 1963.

The earthen and stone structure is about 178 feet high, 940 feet in length and some 10 acres across. And it can discharge up to 29,600 cubic feet of water per second.

Although the dam is not physically manned by DEP officials on a day-to-day basis, the facility is remotely monitored and managed 24 hours a day, seven days a week, through a new Internet-based online system called “Dam Watch.�

The program, which came online in Connecticut last year, allows state inspectors to constantly monitor the conditions of the its 234 dams during adverse weather conditions. The system was developed by the Hartford-based USEngineering Solutions Corp.

The program — which also monitors the Sucker Brook Reservoir in town — gives the DEP instant access to all plans, inspection reports and records related to these dams, as well as real-time access to gauges that monitor precipitation and water levels near the sites.

In addition, the program is also continually updated with rainfall data from the National Weather Service, Art Christian, a senior civil engineer with the DEP, said.

If a significant amount of precipitation falls during a certain time period, Christian said Dam Watch will immediately notify DEP officials, and trigger the Mad River facility to begin retaining water at its site.

“It will tell us that we need to watch somewhere more closely,� he said. “It says to us, ‘Hey come look at this area of the state.’�

And although none of the rain events so far this summer have been siginficant and lengthy enough to cause any serious flooding concerns, Christian said the Mad River Dam has been called into action more than once this season to control the river’s water levels.

“In order for it to do its job, it’s got to start early,� he said of the dam.

The Mad River is one of the main tributaries of the Naugatuck River. And so if the water levels within the river and its watershed are not managed quickly enough during a significant rainfall, it could lead to more serious flooding farther downstream in Torrington and Waterbury.

“We can’t just wait until the last minute and then start storing water,� Christian said.

When the site begins to retain water, the Mad River overflows its banks on the north side of the dam, flooding the facility’s access road and neighboring open woods and fields.

During this time the area is closed to the public, and not reopened until DEP officials feel it is safe to release the dammed up water held at the site back into the watershed.

Christian said while dams throughout the state have been put into action storing river water during heavy rains, it has only been for a short period of time. It would take an extended, two- or three-day steady rainfall to begin raising red flags of flooding concerns.

“Anything with a longer duration, certainly then there is a concern,� he said. “But we haven’t had any storms with so much rain we couldn’t handle... it would take a much bigger event.�

This Aug.19 marks the 54th anniversary of the Great Flood of 1955. See next week’s Winsted Journal for a retrospective on the town’s greatest natural disaster.