A special thank you to Laura Schappert, a previous Watercraft Inspection Steward, for contributing to this blog.
Whether it’s a quiet paddle, a favorite fishing spot, a morning swim, or a shoreline view from your own backyard, healthy waterways shape the way we enjoy summer. But when invasive water chestnut takes hold, those same places can quickly become harder to access, less welcoming for local wildlife, and more difficult for our communities to enjoy.
The good news? Water chestnut is one invasive species where hands-on action can make a big difference.
What Is Water Chestnut and Why Is It a Problem?
European water chestnut (Trapa natans L.) is an invasive aquatic plant that was introduced to the Cambridge Botanical Garden in the mid-1800s. It has since spread throughout the northeastern United States, including New York State, and today it can be found in over 40 counties in New York.
Water chestnut thrives in the shallow sections of lakes, ponds, and slow-moving rivers and streams. It roots itself in the soil and sends up stalks that end in dense floating rosettes of triangular, toothed leaves.
When water chestnut becomes established, it can affect both people and ecosystems. Dense mats can:
- Make boating, paddling, fishing, and swimming more difficult
- Reduce access to shorelines and open water
- Lower the quality of habitat for native plants and fish
- Produce sharp nutlets that can injure people, pets, or even puncture tires
- Reduce oxygen levels in the water when large amounts of plant material die back and decompose
Water chestnut also spreads easily. Each nutlet can produce multiple new plants, and each plant can produce more nutlets that may remain viable in the sediment for several years. Plants, fragments, or nutlets can also hitchhike on boats, trailers, and equipment, which is why it is important for boaters to inspect their gear and clean, drain, and dry their watercraft after each use.
How Water Chestnut Pulls Help
Water chestnut hand-pulls are one of the most direct ways people can help reduce the spread of this invasive plant—and they are an action that both waterfront property owners and community members can take together.
If you live along the water, you have a unique opportunity to protect your shoreline and nearby habitat by removing water chestnut before it spreads. Even small, consistent efforts can help prevent dense infestations from forming and reduce the number of seeds entering the sediment. Connecting with neighbors to coordinate removal can expand that impact across a larger stretch of shoreline.
For community members, joining an organized pull is a hands-on way to support local waterways, learn how to identify and remove invasive species, and contribute to a shared effort that benefits the entire region.
Pulls are typically held in summer, when the floating rosettes are visible but before the fruits ripen and drop into the sediment. In many areas, this window falls between late June and early August.
During a pull, volunteers remove the leaves and fruits from the water. Because water chestnut is an annual plant, removing the floating plant material before it can produce and drop seeds helps limit future growth. Pulling the roots is not necessary and can disturb the sediment at the bottom of a waterbody.
Removed plants can be composted on land as long as they are placed away from water and cannot wash back into nearby waterways. If composting is not available, plants can be bagged and brought to a local landfill.
In New York State, permits are generally not required for individuals conducting small-scale hand-pulling of invasive water chestnuts. However, specific authorizations or Temporary Revocable Permits (TRPs) are needed if the removal involves organized group events on public waters, state-owned underwater lands, or the use of heavy mechanical equipment. Learn more at the NYS DEC website.
Take the Protector Challenge
This month’s Protector Challenge is simple: join a water chestnut pull and help protect local waterways from this invasive aquatic plant.
Water chestnut pulls are hands-on volunteer events where community members work together to remove plants before they can drop seeds and spread. It is a meaningful way to give back to the lakes, rivers, and wetlands that support recreation, wildlife, and healthy ecosystems across the region.
If you own waterfront property where water chestnut is growing, you can also take action by talking with your neighbors and organizing a pull.
Take the Pledge to Protect to be invited to win prizes by taking Protectors Challenges throughout the year!
2026 Water Chestnut Pull Schedule
Join an upcoming water chestnut pull in the SLELO region:
- July 9th, 9 AM, Oneida Lake, NY
- July 17, 9:45 AM- 3 PM, Oswegatchie River, Heuvelton, NY
- July 22, 9 AM- 1:30 PM, Lakeview WMA South Colwell Pond, Ellisburg, NY
- July 22, 9:30 AM- 3 PM Lakeview WMA Mudbrook access, Ellisburg, NY
- July 28, 9 AM- 3 PM, Tibbets Creek, Ogdensburg, NY
- August 7, 9 AM- 12:30 PM, Guffin Bay, Dexter, NY
To receive announcements for upcoming water chestnut pulls in the SLELO region, please click the button below to become a SLELO volunteer and select “aid water chestnut removals” as an opportunity you’re interested in joining.
Help Shape Future Protector Challenges
After you join a pull — or if you are interested in taking more action this season — we encourage you to complete the Protector Check-In Survey.
Your feedback helps us understand how Protectors are getting involved, what actions people are taking, what support is most helpful, and how future challenges can be improved. It is a quick way to share your experience and help strengthen the Pledge to Protect community.
Reporting Your Water Chestnut Removal Efforts
If you organize or conduct a water chestnut pull, it is important to report your efforts to iMapInvasives, New York’s invasive species database. Reporting helps track where water chestnut removal is happening and shows the collective impact of volunteer and partner efforts across the state.
Before and after a pull, organizers can record information about the infestation, removal area, and estimated quantity of plants removed. You can also use the iMapInvasives mobile app to drop observation points along the perimeter of the infestation during the pull.
Visit the iMapInvasives Water Chestnut Organizer’s Dashboard to get These Resources:
- Tips on how to organize a water chestnut pull.
- A guide for reporting your removal efforts.
- iMap tutorials for mapping water chestnut removal efforts.
- View annual reports for removal efforts as they become available.
- View water chestnut pull mapping tutorials
Species Spotlight: Water Chestnut
Water chestnut (Trapa natans L.) is an invasive aquatic annual plant that bears a rosette of floating leaves at the top of a submerged and rooted stem. T. Natans is not the same as the water chestnut that can be found in supermarkets and used in Asian Cuisine.
Origin/Introduction: Water chestnut is native to Eurasia. It was intentionally introduced at the Cambridge Botanical Garden and in a pond in Concord, Massachusetts in the 1800s where it escaped cultivation and spread throughout the northeast U.S.
Habitat: Water chestnut can be found in freshwater lakes and ponds and prefers slow-moving shallow waters high in nutrients with a neutral or alkaline pH.
Impact: Water chestnuts form large-spanning floating mats that shade out native aquatic vegetation and impede water recreation. The pointy seeds of water chestnut can penetrate and injure feet if stepped on. Additionally, the decay of dead water chestnut populations can result in areas with reduced dissolved oxygen levels which affects fish and other aquatic wildlife.
Identification: Leaves float on the surface forming a rosette. Floating leaves are each 3/4th to 1 ½ inches in length, waxy, triangular, and toothed. Green, feather-like leaves up to six inches in length form in alternate pairs along the submerged portion of the stem.
Stems are elongated and typically about a meter long but may reach as much as 5 meters in length.
In Case You Missed It: Beech Leaf Disease: A Growing Threat to Our Forests
The forests of the Northeastern United States and Canada are facing a silent but serious threat—Beech Leaf Disease (BLD). First spotted in Ohio in 2012, this fast-spreading disease is now making its way through New York, recently surfacing in 15 new counties, including Oswego. And it’s not just native beech trees at risk—ornamental varieties are also vulnerable.
Virtual Toolboxes
Visit the Protector’s Virtual Toolboxes below to access resources themed for each category, and to learn more about how to protect your favorite outdoor spaces from invasive species.
Lands & Trails
Lands & Trails
Forests
Waters
Gardens
Communities
Take the Pledge to Protect
Did you enjoy this blog post? Take our Pledge to Protect and get monthly emails showcasing actions you can take to protect your favorite hiking trails, paddleways, forests, garden, and community from the impacts of invasive species!
The Pledge-to-Protect is a fun, positive, inviting, engaging and rewarding way to participate in invasive species prevention and management.
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