Lake levels could be a perennial headache, thanks to changing rain patterns

LACONIA — Fall is lake draw-down season, when lakes regulated by dams are allowed to drop so shoreline property owners can perform maintenance to their docks, boathouses or other waterfront structures. That is, except, in the Lakes Region, where the lakes remain at their normal levels.

That’s because Lake Winnipesaukee doesn’t get drawn down in the fall, unlike other lakes. And Winni’s downstream lakes — Opechee and Winnisquam — are on an every-other-year schedule, and 2023 is an off year.

Even without a drawdown to consider, it’s been a tricky task to manage the level of Lake Winnipesaukee this year, said Dan Mattaini, operations and maintenance engineer for the state’s Bureau of Dams, which is part of the Department of Environmental Services.

“Whenever we have flooding challenges, it’s certainly a challenge,” Mattaini said. And 2023 was a year of flooding, caused by heavy rains. A line graph showing rainfall for Winnipesaukee shows the watershed received above-average precipitation for the whole year, consistently above the average levels for the previous 22 years. At this time of year, the area has usually received about 40 inches of rain. Instead, it has rained 48 inches so far, which is the amount expected by the end of December, rather than the beginning of November.

Heavy rains received in June and July helped to push the level of Winnipesaukee to record highs for July, according to records that go back to 1982. It took a while for dam operators — Winnipesaukee is managed by outflow at the Lakeport Dam — to get the lake back to within the normal range, but they’ve been able to keep it there, more or less, since.

Mattaini said that when the lake levels are high, dam operators are often caught between the interests of two communities — one upstream of the dam, and one downstream.

“Of course, we want to get the lake down for the residents there, but we’re limited to how much water we can release because it can be too much water downstream,” and create flooding. “We have to share the pain.”

There’s likely to be shared pain for summers to come, as climate predictions call for precipitation patterns with fewer but heavier rain falls, and a growing number of dry stretches in between. When lakes are high, it creates hazardous situations, as there’s often debris washed into the lake that can damage boats. Some obstacles, such as rocks, which are normally in plain sight, are hidden just below the surface. It can also create environmental problems in the form of shoreline erosion and more pollutants washing into the lake.

Dam operators could hold the lakes at a lower level to account for these heavier rainfalls, but that, too, comes with its own risks. If that heavy rain doesn’t come, evaporation could push the lake level too low, which then creates its own boating hazards and unhappy shoreline property owners.

“We do the best we can to keep everyone happy,” Mattaini said.

The case for no-wake

At the NH Lakes Association, Andrea LaMoreaux said managing lake levels is a “balancing act” between competing interests. “The communities upstream and downstream have to work together on water level management.”

LaMoreaux, president and policy advocate for the Lakes Association, said her organization’s phones were ringing all summer with complaints about high water levels all over the state.

“It can be a really tough issue in lakes. Some people want lake levels high, some people want lake levels lower. Managing lake levels can be challenging in normal situations,” LaMoreaux said. Changing weather patterns are likely only to make that task more challenging in coming years.

NH Lakes Association is primarily focused on the water quality and ecological health of the state’s lakes, and from that perspective, high lake levels are cause for concern.

“Whenever there’s flooding, there’s a lot of pollutants washed into the lake. If we have big wakes being made in the lakes, those wakes are going to travel further onto the shore,” and will wash sediment, pollutants and nutrients from the shore into the water. Those can increase turbidity in the water, as well as toxins, and can feed blooms of harmful cyanobacteria.

“There’s a whole host of environmental problems,” LaMoreaux said.

Yet if the lakes drop too low, it can limit access to the water body.

One step that can ameliorate the hazards of a high water level is declaring a “no-wake” rule, in which motorized boats can only travel at the minimum speed necessary to maintain control. Some called for a no-wake rule this summer, but without positive response from the state government.

One person who supported the request for no-wake was Elizabeth Harper, executive director for the Lake Sunapee Protective Association.

“Lake levels started to rise, a lot of people in the local area expressed concern,” Harper said. Docks in Sunapee were becoming swamps, boat wakes were washing up on shorelines and septic systems were inundated, she said.

“We tried to reach out at the state level, reached out to the governor’s office. It kind of felt like everyone recognized that there was a problem but no one knew who should take the lead and make the call,” Harper said.

Tired of waiting for someone else to act, the Lake Sunapee Protective Association acted on its own. In July, the association issued an emergency no-wake pledge, urging its membership and others in the community to agree to travel at headway speed only on the lake until it receded back to normal levels.

“Even though it didn’t technically have any legal teeth, it was something people could share with their neighbors, marinas could put in on their bulletin boards. It got a lot of support for that voluntary action,” Harper said. “It was pretty successful.”

Sunapee has five public boat launches, and Harper said there’s a good mix of local residents and visitors who boat on the lake. She said there were many “quiet” days on Sunapee, even at the height of summer, thanks to the no-wake pledge. Once the level dropped back to normal, the association let everyone know it was safe to go back to usual boating.

“I think everyone recognized that it was an emergency situation,” Harper said. Yet, it’s an emergency that is likely to return.

Yes, heavy rainfall is immediately to blame, but the conditions on the ground matter, too, Harper said. If the soil is already saturated, then more of that rain is going to flow across the top of the ground and immediately into the lake. The more development that occurs, and the more impervious surfaces there are in a watershed, the easier it will be for soil to become saturated when the heavy rains arrive.

And, if that development takes place in wetlands, which can absorb and slow water as it flows through a watershed, that only exacerbates the problem, Harper said.

“With climate change, and increased development being a given on our horizon, this is an issue that’s going to come up more and more,” Harper said. She expects the experience of 2023 to “be the norm in the future.” Looking ahead, she said she would like clarity as to who, at the state level, has the authority to declare a no-wake order on a body of water.

“For some lakes, it might be any time we’re over a certain level, we’re automatically at a no-wake situation,” Harper said.