NH LAKES

LakeSmart Program

nhlakes.org
MLPOA partners with NH LAKES in furthering its mission of protecting the health of our lake. MLPOA recommends that lake-side property owners participate in the NH LAKES-sponsored program entitled LakeSmart. Each month, the MLPOA calendar will include a LakeSmart healthy-living tip to support the goal of lake-friendly living.

A Lake-Friendly LIVING Program: LakeSmart is a free, non-regulatory, voluntary education and recognition program. The goal of LakeSmart is to encourage property owners to maintain their home and property in ways that protect lake water quality, wildlife habitat and property values while enjoying their time at the lake.

How to Become LakeSmart: Take a 15-minute online, confidential, self-assessment survey provided by NH LAKES. Afterward, you will receive a personalized follow-up report full of tips and ideas to make your property lake friendly, functional and beautiful.

Request a Site Visit: Once your updates are completed, you can request a FREE and confidential follow-up visit from a LakeSmart evaluator. Visits take approximately one hour, or you can submit photos instead.

Receive a LakeSmart Award: After a site visit by a LakeSmart evaluator, you will be eligible to receive the LakeSmart Award, a plaque that can be proudly displayed on your property, signifying your commitment to protecting the lake you love.

Lake Monomonac LakeSmart Participants: To date, 13 Lake Monomonac property owners have taken the LakeSmart Lake-Friendly Living Program’s self-assessment survey offered by NH LAKES. Of those, ten properties have had site visits, which resulted in two properties receiving the LakeSmart Award.

Want to learn more? Email your interest to lakesmart@nhlakes.org

Dam: Controlling the Water Level of Lake Monomonac
At the time of this writing (fall 2024), the MLPOA and WSLA are jointly proposing modifications to the operating equipment of the Great Dam. Replacing the existing flash boards with a new gate system is expected to improve the control of water flow and reduce the maintenance required by Winchendon DPW. A decision should be forthcoming in the spring of 2025.

Lake Monomonac encompasses about 711 acres, 594 in Rindge, NH, and 183 in Winchendon, MA. It has an average depth of about 11 feet, and is fed by many brooks and streams, the largest coming in from Converse Meadows.

The lake has two outlets, both in Winchendon. The first, known as the Great Dam or main dam, is located at the southeast end of the lake. It is a 333-foot-long earthen-embankment dam that is about 13 feet high and 28 feet wide at the crest. It has stone riprap on the lake-side face for erosion control. East Monomonac Road traverses the top of the dam. A concrete box culvert with flash boards, or stop logs, regulates how much water passes thru into Mirror Pond. The Red Dam controls flowage out of Mirror Pond.

The second outlet is the spillway, also referred to as the overflow or emergency spillway, at the southwest end of the lake. Located off the north side of West Monomonac Road near Route 202, it is a concrete weir of about 140 feet wide, equipped with flash boards to control water flow.

These two structures have traditionally been the primary hydraulic controls for the lake. The challenge through the years has been releasing enough water to prevent flooding and maintaining the agreed-upon lake height. The water rights, fall drawdowns and summer heights have been controversial discussion points for many years and are beyond the scope of this article.

Lake Monomonac started out as a small, river-like pond. Through the years, its size increased after dams were constructed at the outlet leading to Miller’s River in Winchendon. One interesting note is that in 1800s, Rindge was primarily a farming community, while Winchendon was actively pursuing manufacturing opportunities. In fact, in her booklet From Cotton to Cottages, Wilma Allen relates that the “Proprietors of Winchendon” encouraged people to build water-powered mills along rivers and streams, offering incentives such as 100 acres of land with the stream to do so. As a result, Winchendon soon had mills for wood shingles, wooden toys and textile products, among other things. The exact date of the first dam on Lake Monomonac is unknown, but in 1843, the mill owned by Springs Manufacturing in Winchendon Springs was offered for sale. Joseph White was the successful bidder and secured the building, dam and flowage rights. White immediately set about expanding production and upgrading the area, including the mill pond and dams. His company, White Brothers, became one of the largest producers of dyed-cotton denim. It continued to operate until 1953, when economic factors forced its closure. Several years later, in 1958, White sold everything, including the dams and water rights, to Monomonac Lake Shores, Inc. Monomonac Lake Shores promptly raised the lake level and sold land lots in the Narrows and on what is referred to as Stump Pond. Little dam maintenance, however, was performed, as noted in the headline of the May 9th, 1968, edition of the Winchendon Currier: “Main dam owned by Monomonac Lake Shores rotting timbers — main gate might give way wiping out Spring Village.”

In October of 1972, Monomonac Lake Shores deeded the dams and water rights to the Town of Winchendon. Funds were donated ($1,500 each from MLPOA and the Town of Rindge, and $3,000 from the Town of Winchendon) for repairs to the main dam’s woodwork and for some excavation to improve water flow from the sluiceway. This effort, however, proved to be a stop-gap measure only, as water still could not be released fast enough during snow melt or heavy rainstorms.

In December of 1975, after severe flooding, the Town of Winchendon declared a limited State of Emergency when an inspection of the earthen dam indicated a possible collapse. Emergency work was performed by constructing a cofferdam around the site. A 30-inch ductile iron siphon pipe was installed and became the means of regulating water levels. Work was also performed at the overflow spillway on West Monomonac Road. The town was rightfully praised for its rapid response to this emergency. However, this too proved only to be only a stop-gap measure. In June of 1984, a storm of over five inches of rainfall once again caused severe flooding.

The State of Massachusetts then authorized $200,000 in funding to reconstruct the emergency spillway and upgrade the control structure of the main dam. Finally, in 2004, a new dam was constructed and is still in use today. Water levels are now dictated by an Order of Conditions from the Winchendon Conservation Commission with concurrence of the U.S. Army Corps of Engineers. These conditions are renewed every three years. Presently, the lake is drawn down on October 15th and is refilled starting April 11th.