New York City Department of Environmental Protection Commissioner Carter Strickland announced Wednesday that construction has begun on a $21.2 million project to connect the Catskill and Delaware aqueducts for the first time.

The two aqueducts together convey approximately one billion gallons of water each day to the city from six separate reservoirs located in the Catskills.

The interconnect project at the Delaware Aqueduct’s Shaft 4 in the town of Gardiner in Ulster County will allow DEP to move as much as 365 million gallons each day from the Delaware Aqueduct into the Catskill Aqueduct, providing additional operational flexibility and another tool to reduce turbidity in the water supply system after large storms.

Connecting the aqueducts will also allow DEP to temporarily shut down the Catskill Aqueduct to perform work to the tunnel lining that will optimize its capacity. This work will be done in preparation for the anticipated shutdown of the Delaware Aqueduct for needed repairs between 2021 and 2022, during which the Catskill Aqueduct will be relied upon more heavily to meet the city’s demand for water.

Construction of the interconnect over the next three years is expected to create approximately 75 jobs, with the vast majority going to local union workers in the Hudson Valley.