NEW YORK CITY WATERSHED — The Delaware Aqueduct, a tunnel that conveys water from the Delaware reservoirs to New York City, is an imposing structure. The 85-mile-long tunnel was put into service in 1944, and it conveys around 50-60 percent of the city’s drinking water.

A pair of leaks have been identified in the Delaware aqueduct in the fairly-recent past, one in late 1990 in Roseton, near Newburgh, and the second 1992 in the Ulster County town of Wawarsing. The total leakage data is estimated at around 20 million gallons per day (MGD)—for reference,  the aqueduct currently delivers between 500 and 600 MGD—with 95 percent coming from the Newburgh portion.

The repair of these the leaks is a task as imposing as the aqueduct itself. It requires the tunnel to be shut down for months at a time, while a bypass tunnel is connected before and after the leaks.

The New York City Department of Environmental Protection (DEP) has dug that bypass tunnel already; the planning for the project has been ongoing for decades, and it completed its SEQR process and public hearings in 2016. Now, the DEP is preparing to take the next step, to shut down the aqueduct and to connect the bypass tunnel.

The DEP plans to withdraw more water than usual from the Delaware system reservoirs over the next few months, allowing reservoirs in the Catskill and Croton systems to stay relatively full. Once the aqueduct shuts down in October, the DEP will use more water than usual from the Catskill and Croton reservoirs, to make up for the missing water from the Delaware.

The DEP and its partners have been conducting presentations throughout the process to explain the project and its implications. The next presentation upcoming will be hosted by Jeff Skelding, executive director of the Friends of the Upper Delaware River, at the Thursday, April 7 meeting of the Upper Delaware Council. For more information on that presentation, visit bit.ly/delaware-aqueduct-presentation.