May 29, 2026

Hailed as “One of Civilization’s Outstanding Victories,” Catskill System Was Completed in 1926

A Century Later, Ongoing Investments Ensure System Will Serve New Yorkers for Next 100 Years

GILBOA, NY — New York City Department of Environmental Protection (DEP) Commissioner Lisa F. Garcia today celebrated the centennial anniversary of New York City’s renowned Catskill water supply system by announcing the completion of a 20-year, $568 million upgrade of the Gilboa Dam at the Schoharie Reservoir.

The upgrades bring the system’s northernmost reservoir up to modern standards and will allow it to serve New Yorkers for the next 100 years.

In the summer of 1926, workers sealed the Gilboa Dam, allowing the Schoharie Reservoir to fill for the first time, holding roughly 20 billion gallons of drinking water. This capped nearly two decades of construction on the Catskill system and the northern-most reservoir that helped fuel New York City’s explosive growth throughout the 20th Century.

At the time, the New York Times hailed the Catskill system as “one of civilization’s outstanding victories.” A hundred years later, the City has finished a major modernization of the Gilboa Dam — work that has been planned, designed, and constructed over the last 20 years. This work is part of continuing investments to ensure the Catskill system continues to serve New Yorkers for another 100 years.

“As we celebrate a century of the Catskills water system, we are also investing in the next 100 years of clean, reliable drinking water for New Yorkers,” said Mayor Mamdani. “The water that flows from our taps is only possible because of generations of public investment, extraordinary engineering and deep partnership between New York City and communities across New York State. With the completion of this $568 million upgrade to the Gilboa Dam, we are protecting one of the finest water systems in the world and delivering the best-tasting water the country has to offer for millions of New Yorkers.

“With the completion of the $568 million upgrade of the Gilboa Dam, we are doubling down on the well-being of millions of New Yorkers who rely on the Catskill system for clean, safe, world-class drinking water,” said Deputy Mayor for Operations Julia Kerson. “As we mark a century of this incredible infrastructure’s service to our communities, we also recommit to the relentless collaboration and problem-solving that makes this feat of engineering possible.”

“For a century, New Yorkers have relied on the Catskill system to deliver what many proudly call ‘the champagne of tap water,’” said DEP Commissioner Lisa F. Garcia. “In completing the modernization of the Gilboa Dam, we are strengthening the engineering marvel built by past generations, preparing it for the challenges of our changing climate, and ensuring that millions of people can continue to enjoy safe, high quality drinking water. This is the kind of long-term stewardship New Yorkers deserve, and the kind of investment that keeps our water among the best in the world.”

Work on the Catskill system began in 1907 with the 92-mile-long aqueduct to bring water from the planned Ashokan Reservoir in Ulster County to the city. In 1917, with the aqueduct and Ashokan, Kensico and Hillview Reservoirs complete, Catskill water reached New Yorkers in all five boroughs. Work began soon after on the system’s northern expansion to Schoharie County with the construction of the 18-mile-long Shandaken Tunnel to carry water from the Schoharie Creek to the Ashokan Reservoir. In 1926, the Gilboa Dam fully impounded the Schoharie Creek into a reservoir, completing the system. Today, the Catskill system provides about 40 percent of the water serving more than 9 million people in New York City and the Hudson Valley.

DEP’s $568 million investment reinforced and refaced the dam, rehabilitated the inlet to the Shandaken Tunnel, and built a new high-capacity drainage system — called a low-level outlet — that can empty the entire reservoir in under two weeks. The low-level outlet enables DEP to control the water levels in the reservoir. DEP also restored the surrounding landscape with more than 100,000 newly planted trees and shrubs and added a public scenic overlook including displays of Gilboa fossils, nearly 400 million year-old petrified tree stumps from one of the oldest known forests on earth.

“The completion of the upgrades to the Gilboa Dam mean millions of New York City residents can be rest assured they’ll have access to plenty of safe drinking water — and we know safe drinking water is foundational to good health,” said New York State Department of Health Commissioner Dr. James McDonald. “The State Health Department will continue to work with New York City to ensure source water is protected now and for generations to come.”

“The Gilboa Dam at the Schoharie Reservoir is truly a modern marvel. This centennial milestone is cause to celebrate the century of work that supports a critical drinking water supply for millions of New Yorkers. DEC looks forward to continued partnership to protect the environment and this vital watershed for decades to come,” said New York State Department of Environmental Conservation Commissioner Amanda Lefton.

“Special recognition is due to the New York City DEP on the 100^th anniversary of the Catskill System and with the upgrades at the Schoharie Reservoir,” said Schoharie County Board of Supervisors Chairman Bill Federice. “This milestone highlights the significant progress made as the DEP and local communities have come together to work side by side in our mutual interest. The open communication has resulted in increased cooperation between the DEP and the watershed community, a partnership we look forward to continuing.”

About the NYC Department of Environmental Protection

DEP manages New York City’s water supply, providing approximately 1 billion gallons of high-quality drinking water each day to nearly 10 million residents, including 8.3 million in New York City. The water is delivered from a watershed that extends more than 125 miles from the city, comprising 19 reservoirs and three controlled lakes. Approximately 7,000 miles of water mains, tunnels and aqueducts bring water to homes and businesses throughout the five boroughs, and 7,500 miles of sewer lines and 96 pump stations take wastewater to 14 in-city treatment plants. DEP also protects the health and safety of New Yorkers by enforcing the Air and Noise Codes and asbestos rules. For more information, visit nyc.gov/dep, like us on Facebook, or follow us on X and Instagram.