Volunteers remove massive pile of invasive water chestnut from Ice House Pond

September 23, 2023

On Saturday Sept 23, a flotilla of a dozen canoes, two kayaks, and one stand-up paddleboard set forth onto Ice House Pond in East Acton. More than forty volunteer “Pond Defenders” fought back against invasive water chestnuts, which have been clogging the north end of the pond and shading out native vegetation.

The Water Chestnut Pull was organized by OARS (the watershed organization for the Assabet, Sudbury, and Concord Rivers) and the Town of Acton Conservation Department. Paddle Boston contributed ten canoes, with paddles and life vests. The Town of Acton Department of Public Works has taken responsibility to remove the heaps of plant material and take it away to be composted. Once up on land, water chestnuts, even the seeds, cannot propagate.

Heather Conkerton, OARS’ Ecological Restoration Coordinator, taught the volunteers how to recognize water chestnuts’ distinctive leafy rosettes. The rosettes spread out on the water surface, anchored to the pond bottom by a long, slender stalk. The volunteers’ task was to reach under each rosette, snap it off, and deposit it into a plastic laundry basket in the boat. The goal was to remove the nasty, hard, sharp “nuts” that grow on the bottom side of the rosette and give the water chestnut its name. If not removed, the nuts fall to the bottom of the pond and lodge into the mud, where they can remain viable for 10-15 years, according to OARS’ Water Chestnut Management Guidance and Plan.

Most of the volunteers had never pulled water chestnuts, and some had never paddled a canoe. But with helping hands and advice from one another the boats got launched and headed out onto the pond. At first, they encountered isolated rosettes and small clumps. But as they moved towards the shallower north end of the pond, the chestnut infestation thickened, until eventually each boat was surrounded by a continuous carpet of floating green leaves. Volunteers began scooping, snapping, and dumping rosettes into their baskets, occasionally stopping to disentangle a pointy, clinging nut from their gloves or clothes. The recruitment brochure had warned that volunteers would get wet and dirty, and the brochure spoke the truth.

As the baskets filled, each boat made its way back to the boat launch. Enthusiastic shore-based volunteers grabbed each full basket, swapped it out for an empty one, and carried the invasive plant material well away from the water’s edge. Conkerton counted baskets as the contents were dumped into the growing heap. Estimating number of plants from number of baskets, she figured that over  16,400 plants had been pulled from the pond by the end of the morning.

People and canoes at a shore with baskets of water chestnuts.
Photo credit: Kim Kastens

The Acton Conservation Department and OARS are planning another water chestnut pull for next spring, aiming to get at younger plants, before they form nuts. To be notified about the next chestnut pull, email Acton Land Stewardship Coordinator Ian Bergemann at ibergemann@acton-ma.gov. To learn more about water chestnut, visit YOU can control water chestnut! For the history of Ice House Pond, see Nashoba Brook history at the OARS website.


Help support the cost of bringing accurate, relevant news to the Acton community.


Sign up to receive a weekly email newsletter providing links to our new articles.


Look here to access all articles in your areas of interest.