When asked about this state’s greatest treasures, the late U.S. Senator Daniel Patrick Moynihan would invariably start extolling the one-of-a-kind virtues and wonderment of the New York City water system, and in particular the long underground aqueducts that drew needed H2O from the Catskills for delivery via urban taps.
Up here where that water’s been drawn from for over a century now, as well as in those areas under which the tunnel aqueducts that carry it to our south run, talk has long had an edgier element to it as folks decry the loss of old communities flooded for the city’s massive reservoir system, or the fetid water that’s bubbled up from leaks in the city’s treasured water transporting system.
This month, the New York City Department of Environmental Protection gave an update on its multi-year, multi-million dollar project to clean, upgrade and rehabilitate the Catskill Aqueduct, after shutting down the structure that delivers 40 percent of the City’s water for 10 weeks starting last November. During that time, the City DEP announced in a recent press release, upwards of 200 workers were deployed at more than a dozen locations in Ulster, Orange, Putnam and Westchester counties to clean the inside of its older aqueduct, repairing cracks and other defects, and replacing valves that are connected to the 92-mile long series of tunnels, “cut and cover” aqueducts, and steel siphon.
The work was long awaited for many…and a first act of a much longer production yet to unfold as New York City grapples with decades of aging infrastructure over the coming years.
In southwestern Ulster County, many are wondering whether it will all be too little too late. That’s where one of the two major leaks that the city’s been monitoring since the 1990s, in Wawarsing, was long releasing 600,000 to 800,000 gallons of water per day creating wet basements, contaminated drinking wells (and the need for a slew of state- and federal-funded municipal water systems), along with a recent property buy-back program. For over a decade, angry residents petitioned their local officials, and met regularly with New York City representatives, to plead their cases, speaking of health issues and lost investments.
But that’s all part of an entirely different project, the repair of the Delaware Aqueduct, from the one that reached a milestone this month.
“This complex project to rehabilitate the Catskill Aqueduct has required more coordination and flexible planning than perhaps any in the history of our water supply,” noted DEP Commissioner Vincent Sapienza in the recent press announcement. “I want to thank the laborers who worked around the clock for 10 consecutive weeks, the communities north of the city who prepared and activated their backup water supplies while the aqueduct was out of service, and our DEP engineers and planners who coordinated activities during the shutdown. While we are pleased with the significant progress that was made this year, much work remains to complete the project and ensure this critical aqueduct can serve New Yorkers for generations to come.”
Delivering 1.1 billion gallons of water a day
Sapienza pointed out how the currently in-progress rehabilitation project focuses on the 74 northernmost miles of the Catskill Aqueduct, first completed in 1924, from Ashokan to Kensico Reservoir on the east side of the Hudson. To safely perform the work, DEP has had to periodically shut down the Catskill Aqueduct for weeks at a time. The first shutdown, which occurred in the fall and winter of 2018-2019, allowed experts to inspect the inside of the aqueduct, test methods for cleaning its concrete lining, and repair a few areas where leaks were known to exist.
Among recent accomplishments during the recent water shutdown:
The cleaning, from inside, of a total 32.5 miles, or 171,500 linear feet…from a facility near the Wallkill River in Ulster County to the Croton Reservoir in Westchester County, from which workers removed a harmless, organic film by using stiff scrapers similar to squeegees. DEP estimates it will regain roughly 40 million gallons of transmission capacity in the Catskill Aqueduct by cleaning its concrete lining. A total of 800 tons of organic film was removed during the latest shutdown.
A total of 14,036 linear feet of holes were drilled into the aqueduct to seal leaks by injecting them with a special grout to fill the cracks.
Workers also removed and replaced the first two of 35 century-old valves located at chambers that allow the aqueduct to drain into local bodies of water. The remaining valves will be removed and replaced in future shutdowns.
All of this, mind you, is basically just prep work in anticipation for that major shutdown of the Delaware Aqueduct in 2022, the 85-mile-long tunnel that’s the longest in the world, beginning at the Rondout Reservoir in Ulster County. That’s where the project’s other bypass comes in — from Newburgh to Wappingers and started last summer – along with the shutdown to last between five and eight months. The leaking section of the existing aqueduct near Newburgh will be plugged and taken out of service forever.
The entire system started getting built in a burst of energy between 1907 and 1915, with Catskills water first reaching New York City in 1917. Much, at first, was created using the “cut and cover” method that involved excavating a trench and building the aqueduct at the surface. The Delaware Aqueduct was blasted into being between 1939 and 1945, and now carries approximately 500-700 million gallons per day.
Talk about a means of drawing two views of the New York City water supply system a little closer together.
Join the family! 
