High Water Levels in the Lake Sunapee Watershed
The graphs below illustrate how Lake Sunapee responded to the big rain events during the summer of 2023. Water clarity was greatly reduced but improved to close to historic levels by September for most of the cove locations. Much of the material that flowed into the lake during the storms has settled onto the bottom, but this could add to future water quality issues as the extra nutrients become available for algae and cyanobacteria.
July 29 update:
Storm events wash sediment, nutrients, pollutants from land to water affecting water clarity. LSPA staff and volunteers have been collecting water samples over the last few weeks and transparency, or water clarity, as measured with a Secchi Disk has been greatly reduced due to the heavy rains.
Below is a graphic showing how the Secchi Disk works followed by graphs of recent data illustrating the impact storms have had on lake clarity. The red boxes highlight the Secchi Disk readings in July, which were reduced in almost all of the locations monitored. Click here for more information about water quality parameters measured in the lab.
If you are wondering about safe swimming conditions, the best place to see that information is on NHDES' Healthy Swimming Mapper.
July 20 update:
Thank you to everyone who committed to our Emergency No Wake Pledge!
We are happy to report that Lake Sunapee has returned to levels that are acceptable for normal boating activities, although the lake level is still unusually high for late July. Please remember that wakes erode shorelines even at normal water levels. Regulations that are always in effect require boats to travel at headway speed within 150 feet of any other boat, shoreline or fixed object. We ask responsible boaters to always double that and observe a 300 foot distance from shorelines to reduce erosion and protect water quality. Activities that create large wakes should be restricted to the middle of the lake.
NHDES considers normal water levels on Lake Sunapee to be 1093.15 ft elevation which corresponds to 10.5 ft on the gauge in Sunapee Harbor. So far this summer, water levels were highest on July 11th reaching 1094.64 ft. When water levels surpass 1093.5 ft elevation, or 10.85 on the gauge in Sunapee Harbor, LSPA asks that boaters travel at headway speed to minimize damage to shorelines, wildlife, septic systems, docks, boathouses and lighthouses. On Thursday July 20th at 7 am, the NHDES gauge read 1093.5 ft, returning to water levels acceptable for normal boating activities.
July 19 update:
Water levels on Lake Sunapee were still high on July 19 but were headed back towards normal levels and the Burkehaven lighthouse is no longer inundated. We are still recommending that boaters travel at headway speed until we reach water levels of 1093.5 ft elevation (10.85 ft on the gauge in Sunapee Harbor) which will likely occur by this weekend. This will, of course, be weather dependent and there is still some chance of rain in the forecast over the next few days. We will continue to provide updates.
Click here to see real-time lake level data from NHDES.
Be Aware of Water Quality Challenges and Risks After Heavy Rainfall (press release from NHDES)
Recent rain leads to high lake levels in New Hampshire (WMUR story)
Photo of water level gauge in Sunapee Harbor taken on July 18. Lake levels still remain high on the lake.
Here's the latest status on ramps and public docks around the lake (as of July 27):
The Sunapee Harbor Public Docks are OPEN
Sunapee Harbor Boat Launch is OPEN (local businesses are open and Sunapee Harbor Cruises are running their cruises with caution)
The Georges Mills Harbor Boat Launch is OPEN.
The Georges Mills Public Docks are OPEN.
The Newbury Town Dock is OPEN.
The Sunapee State Park/Beach Boat Launch is OPEN.
You may also check the town websites for updates as well:
No-wake Orders
LSPA is advocating for no-wake orders from the state, and our local representatives are working hard to make that happen. NH Marine Patrol and our town police do not have the authority to change boating speed limits or to issue no-wake orders for the lakes in our watershed, so the orders would have to come from the state level.
If you would like to express your concerns and advocate for change in public policy related to these issues, you can contact NH Department of Safety Commissioner Robert Quinn at 603-271-2791 or through email at robert.quinn@dos.nh.gov. You can express your concerns about safety and about environmental impacts including shoreline erosion and flooding septic systems.
You can also contact your local representatives with your concerns. Their contact information can be found at this link: https://www.gencourt.state.nh.us/house/members/
LSPA will continue to advocate for no-wake orders, but these efforts will be most successful if members of the public also express their concerns.
How to Protect Your Dock in High Water (tips from watermark Marine construction)
If you have a seasonal dock with removable decking, consider removing the deck boards to keep them from floating away.
If your boat is on a lift, make sure it is above the high water level so that the waves cannot move it up and down on the lift.
If your lift has a hydraulic powerpack, make sure it doesn’t get swamped on the dock. Consider screwing it down so it doesn’t get washed off the dock into the water.
If your dock is a permanent dock, keep an eye on the frame to make sure it is not separating from the support below it.
Consider re-tying your boat everyday as high water can cause tie lines to tighten so much that they may break.
Please help protect our lighthouses
We need boaters to travel at headway speed on the lake, especially near the lighthouses. Wakes could easily damage the lighthouses as water levels rise.
Fortunately the weight of the lighthouses will keep the decking from floating, but wakes could cause substantial damage to the structure of the lighthouses.
Thank you to Kara Obey for this photo of the Burkehaven lighthouse taken on July 12.
Septic Systems
Weeks of heavy rains have saturated soils and are causing some septic systems to fail. If you suspect that your septic system isn't functioning properly, please contact your septic company for an evaluation.
You can find more information about septic systems, including a list of local septic system professionals on our website at this link.
lanscaping choices can have a big impact on water quality
During the past weeks of unusually heavy rain you may have noticed problem areas on your property where water is flowing rapidly or pooling on the surface. Stormwater runoff carries sediment and pollutants into lakes and streams and can cause cyanobacteria blooms and other water quality problems. To get free advice about how to address these issues, consider participating in our Watershed Wise program. Your landscaping choices can have a big impact. LSPA’s Watershed Wise Program helps property owners to identify changes that can be made, such as additional plantings near the water’s edge, to improve the water quality of streams, lakes and ponds within the Lake Sunapee Watershed
Be grateful for our wetlands
With weeks of heavy rains, water levels are high and many roads and homes are flooded, but areas with wetlands are faring better. Wetlands are often seen as unproductive areas that should be drained and built on, but it is important to know that they serve many useful purposes. Wetlands reduce flooding, acting as natural sponges on the landscape, with the capacity to hold and store huge volumes of water, reducing flooding of nearby properties. Our recent heavy rains may seem unusual, but they are not unexpected. More frequent intense storms have long been predicted by climate scientists. Part of our plan to adapt to these changing conditions must include protecting wetlands.
