Freedom—May 4, 2023—The past week’s major rain event is a reminder that, as “Smart Report” author Bob Smart has often observed, Mother Nature still holds the cards when it comes to Ossipee Lake.
As worries about the rising lake level were posted online and phoned-in to town officials, long-time lake property owners took to social media to offer a perspective for newcomers: high water is a common occurrence from April to early June.
The combination of snowmelt and rain is often the culprit, and in this week’s event approximately five inches of rain fell in a short period of time on already-saturated ground.
Water rushed into the lake from the four rivers that feed it, and met the usual resistance at the Broad Bay channel as it flowed toward the Ossipee Dam, the lake’s only outlet. As the rain continued, the volume of water increased and the lake level rose at all points.
Pictures of drifting boats and floating docks with missing panels appeared on social media pages, including Facebook’s “I Boat on Ossipee Lake.”
Long-time Ossipee Lake resident Tim Otterbach was philosophical as he sent friends pictures of the Bearcamp River, which had surrounded his home and inundated his cars.
“When it rains, it floods,” he said.
Responding to the social media posts, Goodhue Marina’s Tim Cupka cautioned that “It’s a little early to be putting docks and boats in.”
That was echoed by Berry Bay Association President Roberta MacCarthy, who said it’s likely that many newcomers don’t fully understand the ups and downs of the lake’s water level cycle.
“It’s tough to watch people putting expensive boats and docks in the water in April without knowing it’s a risk,” she said.
Role of the Ossipee Dam
MacCarthy, who also sits on the Ossipee Dam Authority, said the social media posts show some people also don’t understand the role of the new Ossipee Lake Dam, which was completed in 2021.
She said the dam, which is controlled electronically from Concord, is designed to manipulate the lake level for recreation and public safety, and has an emergency spillway to avert catastrophic flooding of the type that devastated the lake in June, 1998, when the water level hit 413.72’—more than 6 ft. higher than normal.
MacCarthy called the new dam a “huge improvement” over the dam it replaced, which relied on local workers utilizing “stop logs” to control the lake’s outflow. But some level of occasional high water is inevitable because the lake acts as a kind of ‘bowl’ to the rivers that empty into it.
“Because it is new, we’re still learning about how much flooding can be controlled by the dam,” she said, noting that the high-water mark for this week’s storm appears to have been 410.2′ at the Bearcamp. At the same time, the water level at the dam was 408.5′.
In Concord, meanwhile, the Dam Bureau at DES was monitoring the high water throughout the rain event, according to Operations & Maintenance Engineer Dan Mattaini. He said the agency’s adjustments to the lake’s outflow has to consider the safety of downriver residents as well as those on the lake.
“We have been doing it in stages, ramping up, so as not to release too great an amount of water at one time,” he wrote.
“Unfortunately, heavy intense rain like what was experienced in the area can still bump up the lake for short periods,” he said.