2020 Hydrilla Eradication Efforts in the Cayuga Lake Watershed

The Status of Hydrilla in CL During 2020-Videos

View the video about the status of hydrilla in Cayuga Lake that were part of the Cayuga Lake Watershed Network Conference held November 4 from 2:30-4 p.m..  Flyer for the original live event

Presentations - times are approximate

2:30 pm Welcome by Hilary Lambert, CLWN Steward/Executive Director

2:40-3:00 pm Michael Greer, Regional Technical Specialist, U.S. Army Corps of Engineers Buffalo District “2020 report, Aurora and Ithaca projects on Cayuga Lake”

3:00-3:20 pm Robert Johnson, Racine-Johnson Aquatic Ecologists “2020 hydrilla monitoring, south end of Cayuga Lake”

3:20-3:40 pm Kathryn (Des Jardin) Monacelli, Hydrilla Project Manager Finger Lakes Institute “2020 update on hydrilla work, Cayuga Lake and beyond”

3:40-4:00 pm Q&A and Announcement of final fall presentation.

Cayuga Lake Watershed Network and  Cayuga Lake Watershed Intermunicipal Organization were co-sponsors for this meeting.

This is the second of three events in Cayuga Lake Watershed Network's 2020 online Fall Community Conference. Each event is recorded and made available at the Network's YouTube channel: https://tinyurl.com/CLWNYouTube

August: Cayuga Inlet and southern end of the lake

The U.S. Army Corps of Engineers Buffalo District administered the 10th and final set of fluridone treatments near Stewart Park, Treman Marine Park launch, Cornell Community Sailing Center, and  Cayuga Inlet. 

Results from recent surveys reveal the need for additional copper treatments (Harpoon granular) at four locations: an area off Stewart Park, and three areas within Fall Creek (see map). According to Bob Johnson of Racine-Johnson Aquatic Ecologists, these areas are responding well to treatments.


July: Fall Creek Lagoon

Racine-Johnson Aquatic Ecologists detected hydrilla in the golf course lagoon in the Fall Creek treatment area and put down benthic mats. They are also monitoring the area adjacent to the lagoon.

June: Cayuga Inlet and southern end of the lake

Hydrilla ( Hydrilla verticillata) was absent from Cayuga Inlet and Fall Creek from 2015-2018. However, in fall 2019, hydrilla patches were found in Cayuga Inlet and the southwestern corner of the lake. The patches offshore of Stewart Park and around the Merrill Sailing Center were treated in 2019 and are being monitored.

The U.S. Army Corps of Engineers Buffalo District (USACE Buffalo) proposes to apply the aquatic herbicides fluridone (Sonar® H4C) and chelated copper (Harpoon® Granular) within an approximately 51-acre project area along approximately 5,500 linear feet of shoreline along Stewart Park, the Cornell Community Sailing Center, and Cass Park on Cayuga Inlet (see larger version of the 

map of southern portion of Cayuga Lake near Stewart Park

Hydrilla Treatment Areas Map 2020). For the USACE Buffalo project, the initial application of Sonar® H4C is targeted for the week of June 22, 2020, and a total of 10 treatments will occur between June and August. Additionally, if there is any significant re-establishment of hydrilla beds in the 51-acre project area, those beds may be spot treated with Harpoon® Granular, on or about the week of August 10, 2020. These spot treatment applications are not expected to exceed approximately 10 acres. Signs will be posted along the lake when the herbicide is applied.

The USACE Buffalo project is being closely coordinated with a project being completed by the Tompkins County Soil and Water Conservation District (TCSWCD) within the same vicinity on Cayuga Lake. The TCSWCD hydrilla project will address two areas, approximately 13.6 acres in size, north of Allan H. Treman State Marine Park (see  map ).


map of herbicide treatment area within Cayuga Inlet

For the TCSWCD project, the application schedule will be the same as the USACE project areas with initial application of Sonar H4C the week of June 22, 2020, and a total of 10 treatments between June and August.

There are no restrictions for fishing, swimming, or livestock/pet water consumption at the proposed application rates of Sonar® H4C and Harpoon® Granular. There are restrictions for using water treated with Sonar® H4C for irrigation. There are also potable water restrictions for water treated with Sonar® H4C and Harpoon® Granular if treated water concentrations are above the thresholds indicated in Table 1, “Water Use Restrictions” ( attached ).

Last updated November 6, 2020