By Peter Lyons Hall
Greenwood Lake Mayor Tom Howley and the Village Trustees had had enough of complaints arriving from property owners and visitors so far this season and so they collectively decided to do something about it that had not been done in quite a while: invite resident with an “all hands on deck” plea for volunteers to help address by manual removal of the growing problem of water chestnuts that had been affecting lake quality in certain areas of Orange County’s largest fresh water lake.
Water chestnuts, [Latin, Trapa Nafans] are an invasive aquatic plant with a dense, floating mass that have clogged the shallow areas of Greenwood Lake’s northeast arm, while reducing water quality, and negatively affecting aquatic ecosystems, recreation, and property values. These plants have voracious appetites for light and resources and outcompete native plants, leading to a decline in biodiversity and a reduction in food and shelter for fish and other aquatic life. In order to keep them at bay the village has used a variety of techniques throughout many decades, including aeration, mechanical harvesters, and state and EPA-approved chemicals to inhibit their growth.
But one of the best ways to minimize their impact is, just like gardening on land, is to get out there and pull the weeds out by their roots, which is what dozens of an initial group of volunteers did on a rainy Saturday, June 7, 2025. “Although the rain discouraged some of our residents from coming out today,” said Mayor Howley, “we are pleased with the progress that we have been able to make so far.” The volunteers had established a kind of “bucket brigade” that began with residents using their kayaks and rowboats, equipped with a plastic bucket or two to fill up. Volunteers were given gloves to protect their hands when uprooting the water chestnuts which can be a little prickly. But when the plants are pulled in the right way the volunteers discovered that the plant root systems gave way fairly easily. When the containers were filled, the boats returned to shore where they were met by a chain of volunteers including Trustee Thais Pilieri, who transferred the contents of the containers to a waiting dump truck. After the first couple of hours visitors could see that a channel had already been cleared into the Northeast arm and that more than 50 buckets of water chestnuts had been removed from the lake.
“It’s a painstaking and laborious job,” remarked Pilieri, “but you can see that we are already making a difference, although a small one, in clearing this part of the lake.” According to the NY State Department of Environmental Conservation, water chestnuts are annual plants that have the following qualities:
- Hollow, air-filled stems 12-15 feet long with fine roots that anchor it to the soil, triangular floating leaves with saw-toothed edges that form a rosette around a central point.
- Tiny, white four-petaled flowers that bloom in June. Each rosette can produce up to 20 hard seeds.
- Seeds that are four-inches long and have barbs along them. Seeds within fruits can remain viable for up to 12 years.
Water chestnuts can be controlled using several methods, including manual, mechanical, and chemical methods. But early detection is key for containing and controlling spread, warns the DEC, which is currently funding research on biocontrol – a study of the effectiveness of predator insects from water chestnut’s native range – in controlling the spread of water chestnut. Yet, that approach could have unintended consequences. The most effective control, however, is to attack the population of plants in the spring before the seeds have a chance to grow.
DEC recommends that harvested plants can be placed in black trash bags and left in the sun before placing into a compost area that is located far away from water sources, or allowed to dry in piles far from water and then incinerate, without risk of spreading the plants. But local officials will be dedicating both time and resources to minimizing the continued impact of water chestnuts to the lake as the season continues. “There is too much at stake for us to stand by and watch the situation get worse,” commented Howley. “We are hopeful that more volunteers can join us in future efforts to eradicate this condition.” He urged any residents who want to join the effort to contact him at 845-903-2967 and leave a message and he will get back to them. Meanwhile he and the Village Trustees are grateful to the number of residents who contributed their time, boats, and efforts during the first of many upcoming days to address the need to preserve the quality of the waterway that is Greenwood Lake.
Photo credits: Peter Lyons Hall
