Hydrilla was discovered in the Washington Crossing section of the Canal in July 2016. Hydrilla is an extremely aggressive invasive aquatic plant that spreads very rapidly and forms dense mats that can choke the flow of water through the canal. A lake management firm was hired in September, 2016 to survey, assess, and map the extent of hydrilla and other problem weeds in the high-priority segments of the Delaware & Raritan Canal. The survey report indicates that, for the 18.31 miles surveyed, submerged aquatic vegetation was collected at 96 percent of the sites, confirming the spatial extent and diversity of vegetation in the Canal. Hydrilla was observed at 56 percent of the survey sites.

On May 31, 2017, the Authority began a low-dose (<4 ppb) herbicide injection of Sonar Genesis for up to 120 days targeting the hydrilla and other nuisance aquatic vegetation. At these low rates, there are no restrictions on fish/fish consumption, human/animal water consumption or contact. There are some recommended water irrigation usage restrictions that have been posted along the tried areas of the canal. All Canal water customers have been engaged in the management planning process and continue to be updated on the status of treatment. The herbicide application is showing promising signs of effectively controlling the Hydrilla and other nuisance aquatic plants. The Authority and consulting firm are monitoring the status of plants and the herbicide concentrations at several points along the Canal.

Click here for monitoring and project information.