Lake Champlain water levels dip toward history

Beaches are bigger. Sandbars are sprouting grass. Vermont's "west coast" has expanded westward this fall as Lake Champlain remains a foot below normal.

Shanley Hinge and Gary Franklin of Charlotte found themselves stranded by the low water a couple of weeks ago, when they couldn't get their 22-foot motorboat out of a dock slip at Point Bay Marina in Charlotte.

"That was the first time we've never been able to get out," Hinge said. "We were just kind of landlocked."

Marina staff agreed to move the motorboat to an empty slip for future trips.

The couple had an easier time Saturday afternoon as they carried windsurfers out into the lake at Charlotte Beach, holding up their boards to avoid scraping the bottom until they walked out deep enough to catch the wind.

The beach was strewn with natural debris suggesting better, wetter days.

Startling as the sight of so much exposed lake bottom might be, reputable sources suggest that a century ago, no one in these parts would have batted an eye.

We're still a foot above low-water marks reached in 1908 and 1941.

Moreover, water levels similar to the ones we're seeing this month — the lowest since 2001 — were commonplace until the mid-1950s, according to records assembled by the U.S. Geological Survey.

Gazing at the lake arguably is more pleasant than scrutinizing data, but a few more numbers might help make sense of the lake shore.

Again, the USGS is willing to oblige:

• Friday morning, the survey's lake-level gauge at Burlington's ECHO Center reported 93.68 feet above sea level.
• The historic average for September and October — the lake's lowest season — is 94.71 feet above sea level.
• Lake Champlain dipped below 94 feet at about 2:15 a.m. Sept. 17.

For reference's sake: Anything over 100 feet is considered flood stage.

This year's shallower-than-usual spell began in April, in the wake of lake levels that were higher than average.

Barring any sudden infusion of moisture in the region, the below-average trend is likely to continue, said Chuck McGill, a National Weather Service technology officer in South Burlington.

Like most of New England this summer and fall, Vermont has experienced conditions that are warmer and drier than usual, McGill said. Lake Champlain's drainage reflects those extremes.

Unlike extended years of drought out West, dry spells in these parts are more reliably broken by converging storm systems, he said: "Eventually, we're going to get some rain."

More puzzling to McGill is the sudden rise in average lake levels that began in the early 1960s.

Without any obvious correlation to drought, McGill guessed that the USGS had changed its methods for measuring baseline sea level sometime around then.

Indeed, points of reference have been changed more than once for Lake Champlain, according to Chris Ryan, who works at the USGS Office of Water Information.

"Normally those are corrected for and I do see that there were datum corrections applied," he wrote in an email, adding that more detailed explanations might be forthcoming from the survey's regional office in New Hampshire.

Adding to the shifting numeric sands: Sea levels have never been constant, said Mike Winslow, a writer and longtime lake scientist who now works with the Vermont Experimental Program to Stimulate Competitive Research, based at St. Michael's College in Colchester.

The lack of impeccably reliable data has not detracted from what Winslow terms "the wow factor" of seeing Lake Champlain at its lowest ebb since 2001.

"That's long enough ago that when people say they don't remember ever seeing it then — it's quite possible they don't remember," Winslow said.

Sandbar State Park in Milton offers a spectacular view of dry land that usually lies beneath the waves, he said: "There's stuff there that I don't ever remember seeing before."

Offshore, boaters have a similar response — and practical reasons to remain alert to the new waterscape.

Docking capacity at the Lake Champlain Maritime Museum has dropped by half due to shallower harbor depths, said Nick Patch, who directs outdoor education programs at the Vergennes nonprofit.

As a precaution against wave action that might intermittently drop boats' keels against the lake bottom, museum staff have shifted the replica Philadelphia II gunship to deeper moorings.

Patch recommended a heads-up to boaters who are unfamiliar with the coastline: Submerged debris is now closer to the surface. Invasive, prop-tangling vegetation, deprived of much of its accustomed shallows, now thrives in what used to be deeper water.

Back at Point Bay Marina in Charlotte, where Hinge and Franklin got stuck this fall, manager Todd Smith said even experienced boaters are coming in for repairs to their propellers and boat bottoms.

"People are finding rocks and whatnot that you normally wouldn't find," Smith said.

He keeps a graph of the lake level on his wall, and said he couldn't remember a time the water had been this low — but the warm weather served as consolation.

"It's a tradeoff," Smith said. "It was just one of the best summers we've ever had."

Lake Champlain: How low will it go?

This story first appeared online Oct. 9, 2016.

Contact Joel Banner Baird at 802-660-1843 or joelbaird@freepressmedia.com. Follow him on Twitter @VTgoingUp. Contact April Burbank at 802-660-1863 or aburbank@freepressmedia.com. Follow her on Twitter at @AprilBurbank. ​

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