Our Work
Watershed Management Plan
In the fall of 2024 MLPOA and WSLA entered into a competitive application process with New Hampshire DES to win grant funding for a watershed management plan (WMP) for Lake Monomonac. In January of 2025, we received the great news that we had been awarded the grant. FB Environmental was then selected as our consultant in a competitive bidding process.
The WMP will identify sources of pollutants and outline the actions necessary to maintain and improve water quality and aquatic life in the watershed. The goal of this project is to protect the lake and surrounding watershed by developing strategies that reduce phosphorus loading.
The first step in the project was to develop a Site-Specific Project Plan (SSPP). This plan lays out, step by step, how and when each part of the study will happen. In early September, the SSPP was officially reviewed and approved by MLPOA, NH DES, FB Environmental, and the EPA.
To launch the project, a shoreline study was conducted on September 10, 2025. Volunteers on five boats reviewed all 475 parcels on the lake (including New Hampshire and Massachusetts). The properties were rated for vegetative barriers, exposed earth (including sandy beaches), signs of erosion, slope of the property and distance of structures to the water. The summation of these metrics generates a consensus shoreline disturbance score which assesses the overall vulnerability of the lake to shoreline erosion and stormwater runoff/nutrient runoff. Individual photos of properties will not be published in the technical report that will follow, however photos will be available to MLPOA/WSLA upon request.
A watershed survey is scheduled for mid-October. It is similar to the shoreline survey, but it covers public roads and all waterfront access points, exploring opportunities to reduce stormwater runoff and erosion. The data from both these surveys will be uploaded into a pollutant loading analysis model, providing important data to be used in determining our water quality improvement goals.
A buildout analysis will also be conducted. This exercise models a scenario in which all available lots are developed to the maximum extent allowed by current zoning and regulations. The results will help us understand potential long-term impact on the lake.
Ultimately, the watershed management plan will outline specific projects aimed at helping us meet our water quality goals. It will also include information on potential grants and funding sources to support implementation.
We are off to a busy start with our watershed management plan. Updates will be provided here as we proceed. A final public presentation of the plan is anticipated in late 2026 or early 2027.
Lake Host Program
The Lake Host Program was created by the NH Legislature in 2000 to minimize the introduction and spread of invasive aquatic plants and animals in NH lakes.
Lake hosts are present at boat ramps to perform courtesy inspections on boats and trailers entering and leaving the lake. These inspections are intended to detect invasive species before they can be transferred into a water body; once established, invasive aquatic animals and plants can quickly and profoundly change the character of a lake and can be difficult and costly to remediate. Financial support for the program comes from various places: MLPOA, WSLA, individuals and state grants managed by NH Lakes.
Water Testing—Volunteer Lake Assessment Program (VLAP)
The New Hampshire VLAP is one of the oldest programs in the state for the protection and preservation of lakes. It was launched in 1985 to establish a citizen-based lake sampling program to assist NHDES in evaluating lake quality throughout the state and to empower citizens with information about the health of the state’s lakes and ponds. This cooperative effort allows state biologists and lake associations to make educated decisions regarding the condition of their lakes.
MLPOA volunteers collect water samples at various locations around the lake each June, July, and August. These sample are sent to NHDES, which analyzes and interprets the data and provides an annual water quality report specific to our lake.
Cyanobacteria
Questions and answers about Cyanobacteria (Click to view PDF.)
Cyanobacteria (formerly known as blue-green algae) are naturally occurring in most lakes, though often in relatively low concentrations. Many species of cyanobacteria grow in colonies that form surface-water “blooms.” Blooms consist of thousands of individual cells and are diverse in appearance, ranging from green, blue-green, yellow, white or black. Research indicates that cyanobacteria concentrations increase as lake nutrients increase.
In 2024, Lake Monomonac, as well as many other nearby lakes, experienced an increase in reported blooms. This increase may be attributed to the use of fertilizers containing phosphorus. Frequent blooms not only represent a health hazard, they impair recreational use of the lake and depress property values.
Potential blooms can be reported through the NHDES Website Bloom Report Form or by scanning the QR code below. NHDES will sample the site to determine if cyanobacteria are present. If concentrations are elevated, it will issue a lake warning (advisory), continue to monitor the affected area until the bloom has cleared and update the appropriate parties. It is advised that if you or your pet comes in contact with cyanobacteria, you rinse off with fresh water as soon as possible.
Invasive Eurasian Water Milfoil
MLPOA works with NHDES to control the invasive Eurasian water milfoil on the lake. Each spring and early fall (if time allows) NHDES surveys our lake and maps where they find milfoil. At present we control the milfoil on the lake with the use of divers harvesting the milfoil. We contract with divers recommended by NHDES. We have a grant agreement with NHDES for costs. (In 2025 it was a 50% grant.) We have treated specific areas of the lake chemically in the past and are now using divers to manually remove the smaller less dense plants that exist today. Today, only smaller/less dense areas exist.
The red dots on the 2025 lake map (right) identify milfoil areas which are being removed by divers.
John Sarasin Lake Education Day
Established in 1969, this joint effort with NHDES was initially titled Lake Ecology Day. In 2005, it was renamed in honor of its founder, John Sarasin. John wanted to impress upon young people the importance of vigilance in protecting lake health. Each spring, fifth grade students from Rindge and Winchendon join NHDES limnologists on pontoon boats supplied and captained by MLPOA members for a day of hands-on water tests that are designed to reflect the health of the lake. NH DES tells us that we are the only lake in NH holding a Lake Education Day!
Lake Education Day a Big Success!
On Thurs June 5, 2025 we had 10 NH DES limnologists, 42 fifth grade students from Rindge Elementary, teachers, and chaperones in 9 boats out on the lake water testing and learning about NH water quality. The kids were very inquisitive—we’re hoping to build future environmentalists! Lake Education Day furthers the MLPOA mission of educating the public about lake stewardship. Thanks to all for helping to make it a wonderful experience for the students by sharing or captaining a boat; RABA (Rindge Acres Beach Association) for the use of their beach in launching the boats; and of course to Laureen Moran, Lake Day Ed Coordinator and Secretary of MLPOA.
