Work is set to begin on a $1 Billion repair of a main aqueduct carrying water from upstate reservoirs to New York City.

The New York City Department of Environmental Protection says site preparation work will begin later this month for the 2.5-mile Rondout-West Branch Bypass Tunnel. The project will allow the DEP to repair leaks in the Delaware Aqueduct.

The tunnel, a section of the Delaware Aqueduct that runs from Rondout Reservoir to West Branch Reservoir, is part of the 85-mile aqueduct that carries more than 500 million gallons of water per day from four reservoirs, about half the city’s daily consumption. It serves about a million residents.

Leaks in the aqueduct waste up to 35 million gallons of water per day.

(AP)