When asked about this states 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 aqueduct that drew needed H2O from the Catskills for delivery via urban taps.

Up here where that waters 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 a edgier element to it as folks decry the loss of old communities flooded for the citys massive reservoir system, or the fetid water thats bubbled up from leaks in the citys treasured water transporting system.

This month, the New York City Department of Environmental Protection gave an update on its multi-year, multi-billion dollar project to clean, upgrade and rehabilitate the Catskill Aqueduct, after shutting down the structure that delivers 40 percent of the Citys 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 aqueduct.

The work was long awaited for manyand 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. Thats where one of the two major leaks that the citys been monitoring since the 1970s, in Wawarsing, was long releasing millions of 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.

The recent emptying of the aqueduct, and multi-decade project to repair its entire length after years of charting its leaks with the aid of robot submarines, will eventually include the completion of a 2.5-mile Rondout-West Branch Bypass Tunnel dug beneath the Hudson and begun in November of 2013.

All is in preparation for an even larger undertaking: the eight to nine month long emptying of the Delaware Aqueduct and rerouting of its waters via another new tunnel under the Hudson as the source of those longstanding Wawarsing leaks get fixed.

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.

1.3 billion gallons a day

Sapienza pointed out how the currently in-progress rehabilitation project focuses on the 74 northernmost miles of the aqueduct, from Ashokan to Kensico Reservoir on the east side of the Hudson. To safely perform the work, DEP must 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 feetfrom 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 thats the longest in the world, beginning at the Rondout Reservoir in Ulster County and conveying about half of New York Citys drinking water every day. Thats where the projects 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 a cut and cover method that involved excavating a trench and building the aqueduct at the surface. The Delaware Aqueduct was blasted into beingbetween 1939 and 1945, and now carries approximately 1.3billion U.S. gallons per day.

Talk about a means of drawing two views of the New York City water supply system a little closer together.

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Fixing the tunnels: Progress report on DEP's Catskill Aqueduct - Hudson Valley One