DEM, Partners Seeking Volunteers To Help Remove Invasive Plant From East Providence Reservoir

Published on Friday, July 07, 2023

PROVIDENCE, RI – The Department of Environmental Management (DEM), along with the City of East Providence and the New England Interstate Water Pollution Control Commission (NEIWPCC), are recruiting volunteers to help remove invasive water chestnut plants from the Turner Reservoir in East Providence. The water chestnut is a virulent aquatic plant that’s native to Asia. It has expanded rapidly in the waterbody. Highly aggressive, it forms dense mats that steal sunshine from and ultimately displace native plant species, alter the habitat for fish and wildlife that depend on it, and interfere with recreational activities such as fishing, boating, and paddling. Volunteers are needed to hand-pull and collect as many of the invasive plants as possible. This management method has proven to be effective at limiting its spread. The water chestnut (Trapa natans L.) is an annual plant that only reproduces by seed, so removing it entirely will eliminate further spread.



Two remaining community harvesting events are scheduled: Tuesday, July 11, from 5-8 PM and Saturday, July 15 from 9 AM to 12 PM. Although registration is not required, volunteers may register here for updates including if the event is rescheduled due to rain. Paddlers who bring their own canoe or kayak, boaters with small trolling motors, or even anglers donning their chest waders can help by plucking plants out of the water. Land-dwelling volunteers can stay ashore and help haul the containers from boats to unload the plants for disposal. Wheelbarrows will be provided to compost the plants on site. Volunteers will be provided with a bucket and gloves to collect the plants. These events are open to all, including high school students or scouts seeking volunteer hours. No experience is necessary.  



"It is much easier and cost-effective to weed out a small patch of water chestnut and stop it from taking over than to treat an entire lake with herbicides, so annual monitoring for early removal is key," said Katie DeGoosh-DiMarzio, Principal Environmental Scientist with DEM’s Office of Water Resources. “Water chestnut is one of the few aquatic invasive plants that can be controlled via hand-harvesting, so it is important for those who enjoy Rhode Island’s lakes and ponds to keep an eye out for this invasive plant to catch it early before it becomes a problem.”



These efforts are part of a larger regional project led by NEIWPCC to help local organizations manage the invasive water chestnut. The project is funded by a grant to NEIWPCC from the Southeast New England Program (SNEP)’s Watershed Implementation Grants to help restore aquatic habitats. Previous volunteer hand-pulling events have been held by the Blackstone River Watershed Council (BRWC)/ Friends of the Blackstone with the Blackstone Valley Tourism Council (BVTC), Lake Quinsigamond Watershed Association, and the Town of Uxbridge, MA. Further upstream, the City of Attleboro is treating Dodgeville Pond to reduce the water chestnuts to address the problem from a holistic watershed perspective. Using SNEP grant funding, the City of East Providence will be working with licensed contractors to treat Central Pond with EPA-registered chemical herbicides to control invasive plants, which currently cover almost half of the 137-acre pond, making it the largest population in Rhode Island and a priority to manage.

DEM has managed water chestnut each year at several locations in the state, with successful annual monitoring and surveillance efforts at Belleville Pond (North Kingstown), Sylvestre Pond (Woonsocket), Carl’s Pond (Cumberland), Olney and Barney Ponds (Lincoln), Omega Pond (East Providence), Spectacle Pond (North Providence), and Reynolds Pond (Coventry/West Greenwich). Consistent effort is required each summer, as seeds of the plant can lie dormant in the muck for up to 12 years. Removal of the plants a few days per year at affected waterbodies is essential to stay ahead of this tireless villain, which multiplies exponentially. It is urgent that the growth of this invasive species is culled, and the populations managed, so it does not spread to other areas in the state or into Massachusetts. 



First documented in Rhode Island at Belleville Pond in North Kingstown in 2008, invasive water chestnut has crept throughout the state and is currently found in 22 locations. The thorny water chestnut seeds easily attach to waterfowl and wildlife and hitchhike to new locations. One seed can germinate into 15 plants through the growing season in June and early July, and each plant can produce up to 20 seeds by the end of summer, for a total of 300 new seeds. Therefore, it is essential that paddlers and lake enthusiasts learn to identify this plant and immediately report any new sightings not listed on the current distribution map by emailing pictures to dem.waterresources@dem.ri.gov. Helpful tips for identify the plant are available here.

For more information on DEM programs and initiatives, visit www.dem.ri.gov. Follow DEM on Facebook, Twitter (@RhodeIslandDEM), or Instagram (@rhodeisland.dem) for timely updates.