Repair Work Underway at Cannonsville Dam

New York City Department of Environmental Protection officials say they are closely monitoring conditions at the Cannonsville Dam in Delaware County.

The dam is on the west end of the Cannonsville Reservoir, which provides water to New York City.

Officials say a muddy discharge was discovered on July 8 from a rock embankment below the dam.

Workers drilling borings for a hydroelectric project spotted water coming from an area near the dam's release chamber.

Representatives of the New York City agency say the drilling appeared to have released ground water that was under pressure. That caused an upward flow of water and sediment that reached the West Branch Delaware River.

The amount of water in the reservoir is being reduced by about one billion gallons a day as workers investigate the situation and make repairs.

The reservoir can hold more than 95 billion gallons. As of Sunday, it was holding about 81 billion gallons.

New York City officials say the condition does not represent an imminent threat to the safety of the dam, which is northeast of the village of Deposit.

Officials have released inundation maps so downstream residents, local officials and emergency responders can learn what could occur in the event of a breach of the dam.