Eradication Project in Aurora

During the summers of 2017, 2018 and 2019, the U.S. Army Corps of Engineers (USACE), Buffalo District, has worked on a project aimed toward the eradication of hydrilla from this portion of Cayuga Lake. This treatment has been successful in reducing the amount of hydrilla approximately 99%, but there is still a trouble spot around Paines Creek.

The USACE is continuing this project in 2020, and will treat with application of Fluidone.  See map of 2020 treatment area (PDF).  It is anticipated that the treatment during the summer months will continue for a number of years.  In addition, the U.S. Army Corps of Engineers is planning to treat some small patches of hydrilla with Harpoon Granular, a copper based herbicide.  See map of 2020 treatment area (PDF).

Click here to see the "Waterfront Owner/User Notification Letter for the Use of an Aquatic Herbicide on Cayuga Lake, Aurora, New York."

Click here to see the "Cayuga Lake at Aurora, New York Control Demonstration Project" 2020 brochure.


National and local experts on hydrilla agree that the use of herbicides is the best method to achieve eradication of hydrilla. The USACE will apply Fluridone in a slow release pellet form, trade name Sonar H4C, to treat the hydrilla in the lake in the primary treatment zone. The primary lake treatment zone consists of an approximately 30-acre area along the shoreline of Cayuga Lake from the outlet of Paines Creek to south of the Wells College Dock.

A granular copper-based herbicide, tradename Harpoon Granular, will be used to spot treat small areas of hydrilla that are outside of the main treatment area. The spot treatment zones are located north and south of the primary treatment area. This copper-based herbicide may also be used for spot treatment of limited areas within the main treatment area that do not respond well to the fluridone application.

It is anticipated that the Fluidone treatment will take place once a week, beginning June 25th and running through the first week of September. The copper treatment will take place in late August 2020.  The herbicide products will be applied by a New York State licensed professional applicator to the treatment area.

Water Restrictions

At the levels at which the Fluridone or Harpoon Granular will be applied, there will be no restrictions on drinking, fishing, swimming, boating, or domestic use of treated water. There may be some restrictions on watering certain plants with fluridone treated water.

Wilson’s Disease

People with Wilson’s Disease have increased sensitivity to copper and should consult their physician regarding the application of Harpoon Granular and any precautions that should be taken.

Water Monitoring

The Cayuga County Health Department will conduct water quality monitoring of the public drinking water and the public bathing beach, when the beach is open, during this treatment period. View 2020 sampling results when they become available as well as previous year’s results (2018 sampling results and 2019 sampling results).

Hydrilla Plant