CANNONSVILLE RESERVOIR, NY — The New York City Department of Environmental Protection (DEP) provided an update on the repair and monitoring efforts downstream of Cannonsville Dam. On August 10, engineers and work crews began the second stage of repairs at the site. This stage focuses on sealing shut the original boreholes that led to the cloudy discharge downstream of the dam. To close these boreholes, engineers will inject a high-pressure grout (similar to concrete) that will move inward to seal the original holes and expand outward to fill any eroded areas that were created by the underground aquifer as it mobilized sediment from the area. This work is expected to take approximately two weeks.

Operations at Cannonsville Reservoir have returned to normal for this time of year. DEP is no longer diverting drinking water from the reservoir, instead relying on water from Pepacton and Neversink reservoirs to balance storage across the Delaware System. Downstream releases from Cannonsville have also returned to normal levels under the Flexible Flow Management Program. DEP is currently releasing 500 cubic feet per second, or roughly 325 million gallons per day, from the reservoir. There are roughly 24 billion gallons of cold water in Cannonsville Reservoir—enough to last well into October under normal release and weather conditions.