Winchendon Springs Lake Association: Lake Monomonac

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Winchendon Springs Lake Association: Lake Monomonac The Winchendon Springs Lake Association was founded to insure the quality of our lake community. Construction was completed in 1923.

Lake Monomonac is formed by Lake Monomonac Dam on the Lake Monomonac River in Worcester County, Massachusetts and is used for recreation purposes. It is property of Town of Winchendon. Lake Monomonac is a man-made lake between New Hampshire Massachusetts. It was created from a small pond in New Hampshire by the construction of dams on the North Branch of the Millers River, a tributary of the Connecticut River. Lake Monomonac is 711 acres in size with 425 acres in New Hampshire and the remaining 286 acres in Massachusetts. A unique feature of the lake is the imposing bow of the ship, the "Santa Maria" facing northward up the main body of the lake. Built in 1942 of rock and concrete, it is a bit of whimsy by a priest, Father Wilfred A. Tisdale, as a vacation retreat and to display and enjoy his collection of rare works of art of genuine museum quality. There are 342 property owners and approximately 200 structures on the Massachusetts side of the lake. Approximately 1/3 of those structures are year round homes. 2 dams at the southeast end of the lake - one large earthen dam, and a smaller poured cement dam down stream about 200 feet. The large earthen dam has a siphon for level control. In addition, there is a large spillway on the northwest end of the lake that constructed with removable splashboards. The town of Winchendon owns the dams and spillway. The control at the siphon lowers the lake level 6-8 feet every fall so that spring run-off cannot endanger breaching the dams. Fishing, boating, swimming, sailing all are enjoyed on Lake Monomonac. Hurons, and various duck life abound. There are no 'public beaches' at present. There is a marina on the northeast end of the lake in New Hampshire that has a public ramp for boat access by non residents. Boat sales, gas and service are available at present. There is also a small town-owned lot on the south west end of the lake nearer the town of Winchendon, undeveloped at present that could give access to the shallower end of the lake downstream from the dams. Water source is from nearly 90 various streams, springs. Since Lake Monomonac is in both New Hampshire and Massachusetts, The Winchendon Springs Lake Association works closely with The Rindge lake association, Monomonac Lake Property Owners' Association (MLPOA) on regular water testing.

Great Information, help protect our lake!FYI, in Massachusetts the state & town of Winchendon both prohibit dumping/raki...
10/17/2026

Great Information, help protect our lake!
FYI, in Massachusetts the state & town of Winchendon both prohibit dumping/raking leaves or yard waste, snow etc into the lake.

The Town of Winchendon Wetlands Protection Bylaw (enacted under Chapter 275 of the town code)

https://malegislature.gov/Laws/GeneralLaws/PartIV/TitleI/Chapter270/Section16

Leaves are natural—how can they be considered litter?! When leaves fall to the ground, they naturally decompose and restock the soil with nutrients and organic matter. But what happens when there’s no soil to land on? What happens to those nutrients when leaves land on streets and driveways that...

⚠️ NHDES CYANOBACTERIA WARNING – LAKE MONOMONACThe New Hampshire Department of Environmental Services (NHDES) has issued...
10/05/2026

⚠️ NHDES CYANOBACTERIA WARNING – LAKE MONOMONAC

The New Hampshire Department of Environmental Services (NHDES) has issued a cyanobacteria warning for Lake Monomonac following testing conducted on October 2, 2026.

NHDES identified two types of cyanobacteria in the water sample:

• Dolichospermum lemmermannii — too numerous to count.
NHDES described the bloom as mixed, with both surface scum and cyanobacteria present through deeper water.

Until the warning is lifted, please avoid swimming or wading in the lake and keep children and pets out of the water. If you or your pet comes into contact with the affected water or visible bloom material, rinse thoroughly with fresh water.

Cyanobacteria blooms can produce toxins that may be harmful to people and animals, and you cannot determine whether a bloom is toxic simply by looking at it.

Please share this information with neighbors, guests and anyone who may be using the lake.

https://www.arcgis.com/apps/dashboards/8d84a6b03acb4efaab571b222c78447b

Cyanobacteria bacteria bloom reported in Coot Bay.
09/24/2026

Cyanobacteria bacteria bloom reported in Coot Bay.

A cyanobacteria bloom has been reported by NHDES in Coot Bay.

The cyanobacteria bloom may be present in different areas of the waterbody and may move around waterbody or wash ashore due to wind or water movement. The cyanobacteria may be dissipating or soon dissipate due to cooler nights. NHDES recommends avoiding water with visible cyanobacteria and keeping pets and children away from water with visible cyanobacteria.

For more information about cyanobacteria click here:
https://monomonac.org/our-work/

To receive NHDES bloom reports, fill out this form:
https://lp.constantcontactpages.com/su/pHPCXq8/healthyswimming

09/17/2026

Want to weigh in?

The Watershed Management Plan that WSLA & MLPOA have been working on all year is now available for final review (deadline October 14th). Comments (due by October 14th) go to Jeff Eisenberg, MLPOA president @ [email protected]

It can be found on our MLPOA’s website:

𝐖𝐚𝐧𝐭 𝐚 𝐛𝐞𝐚𝐮𝐭𝐢𝐟𝐮𝐥 𝐲𝐚𝐫𝐝 𝐭𝐡𝐚𝐭’𝐬 𝐚𝐥𝐬𝐨 𝐠𝐫𝐞𝐚𝐭 𝐟𝐨𝐫 𝐭𝐡𝐞 𝐥𝐚𝐤𝐞?Join us Wednesday, Sept 23 at 6 PM at Beals Library for tips on nat...
09/17/2026

𝐖𝐚𝐧𝐭 𝐚 𝐛𝐞𝐚𝐮𝐭𝐢𝐟𝐮𝐥 𝐲𝐚𝐫𝐝 𝐭𝐡𝐚𝐭’𝐬 𝐚𝐥𝐬𝐨 𝐠𝐫𝐞𝐚𝐭 𝐟𝐨𝐫 𝐭𝐡𝐞 𝐥𝐚𝐤𝐞?

Join us Wednesday, Sept 23 at 6 PM at Beals Library for tips on native plants, less fertilizer, and lake-friendly landscaping!
Free workshop with expert Michele Chalice.

Sponsored by WSLA & MLPOA.

09/14/2026

𝐑𝐞𝐦𝐢𝐧𝐝𝐞𝐫: 𝐓𝐨𝐧𝐢𝐠𝐡𝐭

Lake Monomonac Watershed Management Plan Presentation

Please Join Us Monday, September 14th at 6:30pm
Rindge Wellington Rec Center

Where FB Environmental (FBE), a company specializing in environmental planning, assessment, monitoring, mapping, modeling, and restoration,
will share its findings and recommendatio!

Sponsored by MLPOA and WSLA
Supported by the Rindge Conservation Commission

09/14/2026

Could someone please remove me as an administrator on this page? I no longer reside on the lake. TY

Suzanne Reynolds

Join Us this coming Saturday!
06/17/2026

Join Us this coming Saturday!

Address

Winchendon, MA
01475

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