Saturday, November 7, 2015

Mount Holly Putting Finishing Touches On New Star Lake Dam

Mount Holly Putting Finishing Touches On New Star Lake Dam

  OCT 21, 2015
A new dam to contain Mount Holly's Star Lake is in place and, as of this week, approved by state dam safety regulators. The Friends of Star Lake Committee is reporting that a few finishing touches have also been approved that will improve lake access, but more donations are needed to complete the project.
Friends of Star Lake Committee Co-Chair Ron Unterman reported via the Mount Holly Newsflash listserv that officials from the Dam Safety Section of the Vermont Agency of Natural Resources conducted an on-site inspection on Monday and gave the dam final approval.
"At this meeting we also asked Dam Safety if we could make two modifications to the Odd Fellows berm to improve access," Unterman reported. "The State said yes to both ... Of the five alternatives that we had evaluated with our engineering firm (including ramps, stairs, etc.), these two were by far the best choices. We’re delighted that the State agreed!"
Unterman detailed the two modifications:
  1. Cut away the left side of the berm for about 42” to create a direct access to the beach from the driveway.
  2. On the right side, extend the concrete parapet wall for 14’ and backfill down to its base. This will decrease the grade of the rear slope, take the side hill out of that slope, and get rid of the angled drop off on the back right side of the berm.
The project includes large berms along Lake Street and by the Odd Fellows Hall. In an earlier Mount Holly Newsflash email Unterman explained the berm heights were prescribed by the state.

The old Star Lake Dam, prior to reconstruction.
CREDIT RON UNTERMAN / FRIENDS OF STAR LAKE
"As massive as both berms are, the height was mandated by the State to prevent flood waters from going down Lake St. and to protect the Odd Fellows Hall," Unterman wrote. "We personally, and our engineers professionally, pushed hard for compromise on the necessity and height of both berms, but to no avail. Their locations and height were set to hold back the '1,000-year flood' – this was the required standard for the new dam design. As crazy as that sounds, South Carolina just had a 1,000-year flood, and the U.S. has had six 1,000-year floods since 2010."
Unterman went on to explain the requirement was based on the damage potential should the dam be breached. "The Star Lake Dam is a 'High Hazard Dam' because it poses a level three risk to life and property and therefore requires this level of safety," he explained. "For the record, all new 'High Hazard Dams' in the state need to be built to twice that standard! As an existing dam we were grandfathered."

The new Star Lake Dam was constucted over the summer.
CREDIT RON UNTERMAN / FRIENDS OF STAR LAKE
Meanwhile, the lake is refilling and may take until spring to reach its eventual height, which Unterman said will be about a foot and a half above where the lake has been for the past decade.
Unterman noted the timeframe for the remaining berm work will be dependent on construction schedules as well as incoming donations. He also thanked the 280 families, individuals, businesses and town organizations that have contributed to the project to date, as well as the late Patricia Nye who gave $500,000 to get the effort underway.

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