Managing the water levels in the Great Sacandaga Lake necessitates monitoring the snow levels, a task the lake agency has been performing since 1940.
The data is not only studied by the Hudson River-Black River Regulating District, it is passed on to the National Weather Service for use by that agency’s National Operational Hydrologic Remote Sensing Center.
Michael Clark, the lake agency’s acting executive director, said the data is important because it determines what the snowpack will contribute to the inflow.
Much of the Adirondacks, including large parts of the Sacandaga’s 1,044-square-mile watershed, is still covered with snow. Snow is lingering longer than usual, although Clark said that could be attributed more to the recent temperatures than to the slightly above-average snowpack this past winter.
Agency analysis, conducted by two staff members who snowshoed to designated measuring sites every two weeks, determined that on March 14-15, the average snowpack in the watershed was 25 inches in depth and contained 7.82 inches of water. That compares to the 70-year average of 19.8 inches and 5.62 inches of water.
National Weather Service hydrologist Britt Westergard agreed with Clark that the snowfall was slightly above average for the winter. A weather observer in Piseco, at the northern part of the Sacandaga watershed, measured total winter snowfall at 97.5 inches in that area, she said.
“People think snow is snow,” Westergard said. But, she said, “it is important to know how much water is in there.”
In some locations in the Adirondacks, she said, there was still a foot of water in the snowpack.
Total snowfall and snowpack are different entities, Clark said, explaining that the snowpack can hold the water from winter rains and thaws. While total snowfall inches for the winter might be impressive, Clark said the snowpack never got any deeper in the watershed than about 3 feet.
Agency staffers, Clark said, take snowpack measurements by driving a hollow tube until it hits the ground below the snow. It is removed and weighed, allowing calculations to determine water content.
It takes two days for the staffers to take measurements at 25 locations from Indian Lake in the north to Bakers Mills on Route 8 near Gore Mountain to Peters Corners in Bleecker.
Clark said he and his staff are preparing the final summary for the season.
Snow is certainly a factor in filling up the flood-control lake, but Clark said it will fill every spring regardless. If the snow is inadequate, the rainfall compensates, he said.
As of Friday, the lake was considered full with the water level reaching the designated mark of 768 feet of elevation.
The top of the spillway at the Conklingville Dam is at 771 feet, a mark the spring flow rarely reaches.
The lake has been collecting water for weeks, but Clark said with flows diminishing in the Hudson River, the Sacandaga probably was going to soon start releasing some of its load.
Categories: Schenectady County