A Pond Worth Protecting

Farm Pond is a town gem. Please join the SYC in our efforts to enjoy, protect and preserve the pond for future generations.

Enjoy
Get on the water and have some fun! In addition to sailing and swimming in the summer, you can fish, paddle and windsurf. Or simply sit and take in the beauty of the pond. When it’s frozen in winter, safely fat-bike, skate, or stroll across the frozen surface, enjoying the peace and solitude.

Protect
See something, say something! Learn the rules. If you spot visitors violating them, don’t look the other way. Engage them in a respectful manner and explain the importance of protecting this irreplaceable asset.

Preserve
To maintain the pond for future generations, residents must take care of the property and surrounding areas, avoiding any activities that pose a risk of infestation. Boaters must ensure equipment is free from vegetation.

Monitor
The SYC has partnered with the Town of Sherborn’s Farm Pond Advisory Committee, and Tom Trainor of the Groundwater Protection Committee to assist in monitoring efforts.  SYC staff take samples from the pond regularly and use a microscope to look for the presence of blue-green cyanobacteria, informing community members when the levels of potentially harmful (HCB, HAB) bacteria are high.

Farm Pond Hockey Classic. 2022

Taking plankton net samples. 2021

Waterfront Director Lilian Briggs analyzes a sample for cyanobacteria. 2021

About Farm Pond
Farm Pond is a “kettle” lake, meaning it was formed by the melting remnant of one of the glaciers that melted more than 12,000 years ago. The pond covers about 126 acres and is about 58 feet at its deepest

Fed by a small sparsely developed watershed of about 409 acres, Farm Pond is about 35 feet higher than many of the surrounding smaller ponds, streams, and the Charles River. The earthen berm along the northeast corner of the lake, constructed in the late 1800’s when Farm Pond served as a water reservoir to the Medfield State Hospital, continues to act as a dam that has kept the pond surface a few feet higher than earlier centuries.

An estimated 80 million gallons of water per year flow out of Farm Pond (to surrounding groundwater table and to a small stream that flows behind the berm to the Charles River) or are lost to evaporation, resulting in a dependence of about 45-50 inches of average annual rainfall to maintain the pond’s normal water level. The pockets of cool water, which swimmers often feel on their toes, are the result of seasonal thermal stratification of water layers, due to water density and temperature differences.

Farm Pond has always been an active wildlife area, providing superb habitat to fish and many birds, including geese, ducks, blue herons, eagles, ospreys, cormorants, and hawks. Some species of fish and amphibians that inhabit the pond are relatively rare. The island in the southern portion of the pond is private property; its owners maintain it as a sanctuary for the numerous birds that nest there.

 

History of Farm Pond
In the Colonial Ordinances of 1641– 1647, the Great and General Court of Massachusetts Bay Colony declared that Farm Pond and others in MA larger than 10 acres in size were “Great Ponds,” and that all settlers had the right to fish in them. In the 19th century, Farm Pond provided fish as well as recreational swimming and skating to Sherborn residents. It was stocked with fish several times in the 1870s. By then, ice harvesting was an important Sherborn industry. Several ice houses were located on the shore near Lake Street. The foundation of one can still be seen there. The Clark family, among others, harvested as much as 3,000 tons of ice in a good year, storing the chunks in sawdust-insulated barns, packed in meadow marsh hay and sawdust. As much as 1/3 of the ice would melt before it could be sold at $.30 per pound. A 50- or 100-pound chunk could last in your ice box as long as a week.

Farm Pond August 1886

 

Steamboat Launch

In the late nineteenth century, picnic areas were established at private beaches at several locations. From 1880 until 1893, launches took families and groups for sightseeing outings on the pond. In 1893, one of the launches, the 30-foot, wood-burning, side-paddle steam launch Atlanta, was broken up and its engine converted to run a cider mill.

From 1897 to 1935, only fishing and ice harvesting were allowed on Farm Pond. The Commonwealth of Massachusetts took control of the water rights so that the pond could be used as a reservoir by the Medfield State Hospital. Water was taken to the hospital from the brick “pumphouse” (actually, it houses a valve not a pump) on the eastern side of the Pond, but it was used only for the hospital’s boilers. Water continued to be drawn from the Pond until the Hospital was closed in 2003.

In the Depression of the 1930s, unemployment plagued Sherborn, as elsewhere. WPA projects used local labor to enlarge the beach and build the stone bath house, and to construct the stone retaining wall along the back of the beach. While Farm Pond more closely resembles a lake, its name is probably due to its “Great Pond” status. In 1935, the Commonwealth authorized the Sherborn Board of Selectmen to administer Farm Pond and to establish rules and regulations for its use and protection. In 2010, an Act of the Legislature transferred the Farm Pond water rights back to the Town of Sherborn, at the request of the Sherborn Select Board.

 

Protecting Farm Pond
To maintain the pond’s excellent water quality, excessive nutrients and other contaminants must not be introduced into the pond from activities in the surrounding watershed. Activities of particular concern in terms of potential nutrient contributions include new land use and impervious surfaces, failing septic systems, lawn fertilization and the increasing size of the resident goose population. Increasing lake nutrient levels (total phosphorus), along with increasing ambient temperatures predicted by climate change can lead to decreased water quality caused by eutrophication.

Farm Pond is one of the highest water quality lakes in the MetroWest Boston area, due to two key attributes:

  • Relatively small watershed/lake area ratio (409/126) = 3.24.  This reduces the quantity of pollutants that would enter the lake as stormwater runoff, as compared to other surface water bodies with much larger watershed areas.

  • Largely forested watershed, with only about 30 homes on large 3-acre or greater lot size. This reduces the amount of erosion and delivery of sediments and nutrients to the lake.

Another threat to the pond is the potential proliferation of non-native invasive aquatic weeds. One example species, Eurasian watermilfoil, which has caused serious problems in several lakes and ponds in neighboring Towns, other parts of the United States and Canada. It is commonly spread when fragments adhere to boats, motors, and trailers. When the boat is taken to another lake, the plant gets an opportunity to infest that lake. In some states, it is actually illegal to put a boat in the water if it has Eurasian watermilfoil on it. Milfoil growth is accelerated when it is cut into pieces and left in the water.

The best way of protecting Farm Pond from this infestation is to be sure that it is not accidentally brought in. For this and other reasons, motor powered boats are prohibited on Farm Pond. This ban includes any craft powered by electric motors. All boaters and fishermen must ensure that their boats and trailers are free from any vegetation before entering the water and have the required Town of Sherborn boat permits.

Volunteer Tom Trainor instructing the staff on proper microscope techniques. 2021