Treatment Timeline

This timeline shows only key steps in an attempt to show the progression of the response. Many other important steps have taken place along the way. 


August 26 - 31: New hydrilla infestation found near Myers Park, Lansing


August 13: Chelated copper treatment of 4 acres off Stewart Park


July 5: Sonar Genesis injection unit installed at NYSDEC fish ladder at southern end of Cayuga Inlet in preparation for 2016 treatments

July 22: Sonar treatment begins in Cayuga Inlet. Sonar Genesis injection unit turned on, Sonar H4C pellets applied to pellet treatment zones

August 9-10: Endothall injection treatment in Fall Creek. Sonar H4C treatment begins in backwater areas of Fall Creek. Sonar H4C "bump" treatments conducted in Cayuga Inlet

August 26: Sonar H4C "bump" treatments conducted in Cayuga Inlet and Fall Creek

September 13: New hydrilla infestation discovered in Aurora, NY (adjacent to Wells College)

September 19: Sonar H4C "bump" treatments conducted in Cayuga Inlet and Fall Creek

September 30: All treatments finalized for 2016 season

November 19: End of season public meeting


June 25: Dye study conducted in Fall Creek prior to Aquathol K treatment.

June 25: Annual pre-treatment Hydrilla Public Meeting. Combined with "What's in your Watershed?" lecture series. 

August 18: Endothall treatment in Cayuga Inlet

August 25 - August 27: Endothall injection treatment in Fall Creek

September 1: Sonar Genesis (liquid) and Sonar One (pellet) application begins in Cayuga Inlet. Sonar One application begins in Fall Creek. Sonar H4C (pellet) application begins in southeast corner of Cayuga Lake (30 acre treatment zone)

October 12: All Sonar applications finished for 2015 treatment season


June 5: NYS Law: Boaters are required to remove all visible plant and animal materials from boats, trailers and associated equipment, and to drain boats prior to launching from DEC lands

June 18:  100% of tubers in Stewart Park Pond have germinated, according to monitoring

June 20: Legislative approval requires DEC to develop regulations for boaters to take precautionary measures against the spread of Invasive Species. Legislation sent to the governor.

June 29: First public outreach of the season at the Farmer's Market for hydrilla

July 8: Pre-treatment public meeting

July 17: Endothall Treatment in Fall Creek

July 29: Endothall Treatment in Cayuga Inlet

August 7: Statewide Hydrilla Hunters webinar

August 14: Fluridone pellet (Sonar One) treatment in select areas of Fall Creek

October 8: Fluridone treatments ended

November 18: End-of-Season Hydrilla Public Meeting & Volunteer Thank You Event 

December 1-7: Monitoring/sampling of water ended


June 3: Some tubers sprouting in the inlet. Tuber density far less than 2011 and 2012

June 20: Hydrilla growth in the Cayuga Inlet is 1-2 weeks behind last year, postponing the endothall treatment

July 16: Endothall treatment in Cayuga Inlet

August 14: Sonar (active ingredient fluridone) treatment begins

August 8: New areas of hydrilla growth found  in Fall Creek-- at the entrance of the Stewart Park Pond, within the pond itself, and near the municipal golf course backwater

August 21: Two new small patches (one patch consisting of two smaller patches) found in the southeast corner of Cayuga Lake

September 16: Sonar pellet "bump" application to previously treated areas

September 26: Endothall treatment in Fall Creek to address newly discovered hydrilla. The treatment area consists of 22 acres.

October 10: Fall Creek water monitoring was completed after endothall treatment. Results for Fall Creek Endothall Monitoring 2013.

November 12: End of season public meeting.  

December 2: Cayuga Inlet fluridone water monitoring ended.  Results of the Cayuga Inlet Fluridone Monitoring 2013.


June 19: Public meeting

June 26-27: Endothall treatment in Cayuga Inlet

June 26-July 16: Water quality monitoring for endothall concentrations. Results of Endothall Monitoring 2012.

July 12: Fluridone treatment and water quality monitoring for fluridone begins on the inlet

July 17: A Local Law to Prevent the Spread of Aquatic Invasive Species in Tompkins County passed

July 24: Governor Cuomo Signs Legislation to Protect New York's Waterways and Natural Habitat from Invasive Species

September 21: Hydrilla found in tributary to Erie Canal in North Tonawanda, NY

October 31: Fluridone treatment ends on the inlet

November 7: Final day of water quality monitoring of fluridone

November 7 & 8: Public meetings

November 26: Water quality monitoring for fluridone levels completed. Results of 2012 Fluridone Monitoring

Winter 2012: Hydrilla Task Force analyses plant and water quality monitoring data and works on long-term management plan


August 4: Hydrilla first found in Linderman Creek by Jordan Stark, a volunteer on the Floating Classroom

August 19: Representatives from the City of Ithaca, the Cayuga Lake Watershed Network, the Finger Lakes Region of NYS Office of Parks, Recreation, and Historic Preservation, the NYS Department of Environmental Conservation, and NYS Canal Corporation meet. Hydrilla Task Force formed

September 3-5: Hydrilla surveyed and mapped in the Cayuga Inlet.

September 7: Hydrilla Task Force makes formal proposal for herbicide application and applies for permit

September 14: Formal notification to affected landowners of herbicide treatment

September 19: City of Ithaca request for boaters to voluntarily stay out of Cayuga Inlet

September 23: Paddle docks in Cass Park temporarily closed in response to hydrilla discovery

September 24: Public outreach at Rhinerfest. Water related events cancelled due to hydrilla infestation

October 1: Allan H. Treman State Marine Park Boat Launch temporarily closed by State Parks

October 1-2: Outreach volunteers distributed hydrilla information at Applefest

October 4: Public meeting at First Unitarian Church of Ithaca to share information about the proposed control of hydrilla in the Cayuga inlet

October 5-14: Inlet closed for 10 days

October 10: First endothall herbicide treatment in Cayuga Inlet

October 11-26: TCHD and NYDEC designated water quality monitoring of endothall. Results of 2011 endothall monitoring

October 18-November 23: Bolton Point water quality monitoring of endothall. Results of 2011 Bolton Point endothall monitoring

November 7: End of season public meeting 

Winter 2011: Hydrilla Task Force researches response options and learns about hydrilla eradication and management experience elsewhere in the US.

Last updated September 11, 2019