Work starts on $1.9B water tunnel project

The New York City Department of Environmental Protection (DEP) has begun work on a water tunnel project in the Town of Mount Pleasant that will include vertical shafts and a horizontal tunnel that will be approximately two miles long. The cost of the Kensico-Eastview Connection project is expected to be $1.9 billion. The project is expected to take ten years to complete. A groundbreaking ceremony marked the start of construction.

Vertical shafts will be constructed along with the tunnel itself that will run approximately 500 feet below the surface. The first phase of construction includes site preparation at the DEP campus adjacent to Kensico Reservoir, followed by the digging of the two shafts and then tunneling between the two shafts. The finished tunnel will be 27 feet in diameter and could carry as much as 2.6 billion gallons of water each day from the Kensico Reservoir to the Catskill-Delaware Ultraviolet Light Disinfection Facility in Eastview.

When the Kensico Reservoir is full it holds approximately 30 billion gallons of water. The DEP typically draws about 1 billion gallons a day to meet the demand of 8.6 million residents in the five boroughs of New York City and approximately 500,000 residents of Westchester County whose communities use New York City water.

According to DEP Commissioner Rohit T. Aggarwala, “Creating additional redundancy in our vital water supply system is an essential investment for the long-term resilience of the remarkable feat of engineering that provides more than nine million New Yorkers with a reliable supply of pristine tap water. This project will help us fulfill our commitment to providing consistent and reliable delivery of the highest-quality water to New York City and the growing population centers in Westchester County.”

As part of the project, a water intake chamber at the reservoir will be upgraded, improvements will be made to the DEP’s facilities around the reservoir. A new screen chamber to remove debris from the water will be constructed just north of DEP’s main campus at the reservoir near Columbus Avenue in Valhalla, and the chemical systems used to begin treatment of the water drawn from the reservoir will be upgraded.

The Kensico Reservoir was built in 1915 as part of New York City’s Catskill Water Supply System. In the 1940s, modifications were made so the reservoir could also receive water from the city’s Delaware Water Supply System, also in the Catskills. There are 19 reservoirs, three controlled lakes as well as approximately 7,000 miles of water mains, tunnels and aqueducts in the city’s water system.