OSWEGO COUNTY – Oswego County has a new dog in the fight as it works to control the water chestnut population in the Oswego River. An integrated manual uprooting and herbicide application system now includes the use of a drone.
The Oswego County Soil and Water Conservation District (OCSWD) works with Chase Enterprises, a high-quality infrastructure maintenance service, to control invasive plant species.
“Drone use is new this year,” said Joe Chairvolotti, Oswego County Soil and Water Conservation District Manager. “The contractor continues to use an airboat to apply the herbicide in some places, but he is trying this drone in other places where it could be more effective.
“Allen Chase, the owner of Chase Enterprises, demonstrated the use of the drone at Big Island in Fulton and we were impressed with the results,” he added. “The crew covered about 40-50 acres in two days and the drone didn’t move the water chestnuts as much as the airboat during the application process. It’s a new technology, so we’re still evaluating; but so far we are very happy with the results.
The Chase Enterprises team had to go through a rigorous licensing process and training program in order to use a drone for this herbicide application. The company has received approvals from the New York State Department of Environmental Conservation (NYSDEC) and the Federal Aviation Administration (FAA) to use the drone.
Drone technology has also made it possible to map the areas to be treated. “In preparation for using the application drone to apply the herbicide, we started with a survey drone to map plots previously selected by the OCSWD team,” Chase said. “We then used agricultural mapping software to create an optimized flight plan for the application drone that would ensure full coverage and efficiency.”
He added: “The app itself is self-contained, with the drone itself flying under our supervision. The drone has on-board radar and imagery to avoid any unidentified obstacles in the flight plan. The process worked very well; we believe we have achieved a better result with higher application efficiency than conventional methods.
Mapping water chestnut populations across the river is an extensive process that OCSWD begins a year in advance.
The first step is to determine the areas where treatment, whether by drone or airboat, will be most effective. The contractor, in coordination with the OCSWD, then applies for the necessary permits through NYSDEC and NYS Canal Corp. for herbicide application. At this time, the OCSWD also notifies the riparian owners.
Initial herbicide treatments begin in mid-July and a follow-up treatment is carried out a few weeks later.
“Water chestnut seeds are viable in sediment for 10 to 12 years, so repeated applications may be needed to interrupt the plant’s seed cycle,” Chairvolotti said. “The goal of this whole integrated program is to reduce very dense water chestnut populations enough for hand-pulling to be more effective.”
Pulling water chestnuts by hand is a team effort. The OCSWD hires a handful of college interns — preferably with an environmental background in their studies — to operate the kayaks, canoes and, also new this year, a motorboat. Very carefully, they pull the water chestnut seedlings out of the water by hand to throw them away so as not to spill their seeds. Additionally, some local landowners and environmentally conscious volunteers go out in their own canoes and kayaks at hand-pull events to help control plant populations.
The water chestnut’s life cycle creates large floating mats of vegetation that limit sunlight and limit the growth of native plants. Not only does this disrupt the natural food web and interfere with aquatic ecosystems, but it also significantly reduces the quality of native habitat and hinders recreational use of waterways.
“We’ve made a lot of progress,” Chairvolotti said. “Some areas are showing signs of reduction faster than others. We may not need to treat these areas again, but we are monitoring them to be sure.
“Overall, the program has been very successful in getting some control over the water chestnuts,” he concluded. “For example, 10 or 12 years ago we had over 300 acres of very dense plant populations in the Oswego River and Ox Creek, and now we’re down to just over 100 acres. Due to water chestnuts’ extended life cycle and ease of rapid seed transfer, we may never be able to completely eradicate the plant, but if we can control it and prevent it from spreading, it’s is a “victory” for us. »
To see the drone in action, watch these YouTube videos: