Building The Ashokan Reservoir

In the Catskills watershed, the Ashokan Reservoir would hold 122.9 billion gallons of water at full capacity and would supply approximately 40% of New York City’s daily drinking water needs in non-drought periods. It was constructed under the auspices of the New York City Board of Water Supply (BWS) beginning in 1907. Its weirs, dikes, and the Olive Bridge Dam backed up Esopus waters for twelve miles, necessitating the removal of homes, farms, businesses, churches, schools and other structures throughout the valley. 2,350 residents were displaced as four hamlets were flooded and eight others were relocated. Many of these residents were not paid the full value of their property and were given two months to uproot their lives and move elsewhere. From the reservoir, water entered into the Catskill Aqueduct and headed south through mountains, over 163 miles of terrain, and under the Hudson River to the Kensico Reservoir in Yonkers, NY, which provided a safety net of two weeks water supply for New York City residents.

A black and white photo of a landscape dotted with country houses, dilapitated sheds, and in the distance, a church steeple. The photo is taken from up on a hill of a lightly hilled landscape. It is winter as the deciduous trees are bare. — View of the old town of West Hurley, included in territory taken for the East basin of Ashokan reservoir. December 7, 1906. Source: NYPL Digital Collections, Link.

A black and white photo of an almost bare valley. There is a creek that cuts through the land and falls with horizontal rock strata embedded in the sides. A couple of houses dot the landscape and a mountain range is barely visible through a haze. — Ashokan Reservoir. General view up-stream from Olive Bridge dam, showing Esopus creek and reservoir basin after clearing. September 9, 1913. Source: NYPL Digital Collections. Link.

(Above) Here, the land that now forms the basin of the Ashokan reservoir has been cleared, but not flooded. The image above shows the landscape in transition, illustrating the immensity of this project that transformed life and land in parts of the Catskill region.

A black and white photo during winter time of a two story white house with a wide front porch and two chimneys. There are a few bare trees around and one tall evergreen tree. — Postcard of the Jase Snead Residence found in Brown’s Station in Kingston, New York. Brown’s Station no longer exists. It was one of the towns flooded to create the Ashokan Reservoir. Source: New York Heritage Digital Collections. Link.

A color photo of a contemporary metal sign that reads "Ashokan Reservoir, Former Site of Shokan". The sign is brown with white lettering and a decorative line in the shape of water ripples across the top. — Sign marking the former site of the town of Shokan. Source: Untapped NY. Link.

After the construction of the Ashokan reservoir, some towns, like Brown’s Station, Olive City, Broadhead’s Bridge and Ashton, ceased to exist. Others, like the communities of West Hurley, Shokan, West Shokan, and Boiceville, were relocated.

A black and white map of Olive. The majority of text is unreadable except for a section labeled "Hardenberg Patent" and "Lot 8". The Esopus Creek is a dark line that cuts through the map from left to right. — Town of Olive before the reservoir was built. .

A black and white map with a part of the Ashokan Reservoir noted blue over existing land. A ring of green surrounds the reservoir, indicating NYC land.. — Map of the Town of Olive circa 1890. This map shows the impact of the Reservoir Project on the Town. Both images, source: Town of Olive Archives. Link.

History provided by the Town of Olive

“Nestled in the Catskill Mountains of New York State is 40,000 acres named the Town of Olive. The Ashokan Reservoir geographically divides Olive–north and south. The hamlets around the shoreline are Boiceville, Olivebridge, Samsonville, Krumville, Shokan, West Shokan, and Ashokan.

The passing of the Water Act of 1905 led to the building of the handmade Ashokan Dam on the Esopus Creek and upon its completion in 1916 created the Ashokan Reservoir, a main water supply for the City of New York-Olive’s largest landowner. The demand for pure, clean drinking water for New York City inhabitants changed the course of history for the Town of Olive and still has an impact on everyday life. The Town center and the majority of the Town’s residents were forced from the rich Esopus Valley and relocated to the nearby foothills. In May of 1997 Land Use Regulations, which could become a model for the rest of the country, became effective as a Memorandum of Agreement was signed between Watershed Towns and the City of New York to provide for protection of water quality throughout the New York City Watershed.”

—Source: Town of Olive website. Link.

A black and white photo made up of two photos pasted together onto a backing board. The photo is old and has worn and frayed edges. The photo depicts a concrete dam wall under construction in the foreground, and railway tracks on the right foreground. A large mountain is in the background. — Construction of the Olive Bridge Dam, 1911. Catskill Aqueduct, Croton Division. Source: NYPL Digital Collections. Link.

A black and white photo of a picturesque rocky creek cutting through a forest of evergreen trees. — Ashokan Reservoir. View showing loose stone gorge in Esopus creek at site of Olive Bridge dam. Source: NYPL Digital Collections. Link.

In The Catskills: It’s History and How It Changed America, authors Stephen M. Silverman and Raphael D. Silver quote a report on the opening of the Ashokan reservoir in Hudson Valley Magazine: “Improbably, miraculously, a tiny creek originating high in the Catskill Mountains had been successfully damned to create a thirteen-square-mile drinking fountain for city folk.”

A black and white schematic drawing of engineering plans for a dam wall. It is a cut-away view of a straight horizontal wall on one side that holds the water, and a sloping side on the other side.

A black and white schematic drawing of engineering plans for a dam wall. It is a cut-away view of a tunnel and the surrounding earth.

A black and white schematic drawing of engineering plans for one of the large earth dams for closing the longer and shallower gaps in the rim of the basin. It looks like a triangular volcano like shape with a masonry core wall in the middle. — Diagrams of elements of the Ashokan Reservoir, Olive Bridge Dam, and Catskill Aqueduct from the Board of Water Supply’s report on the inauguration of construction at Peekskill, NY.
Source: Library of the University of Illinois College of Engineering via Internet Archive. Link.

“On October 11, Acting Mayor Ardolph Kline presided over a special luncheon attended by 500 engineers, officials and invited guests who also toured the dam site and reservoir, a reservoir whose name may be derived from the Indian word “sokan,” meaning “to cross the creek.”

— Liquid Assets by Diane Galusha.

A black and white photo of a large crowd of white men on a bridge looking at the camera which is up high. Some buildings can be seen in the distance. — Group of visitors on top of Olive Bridge dam at celebration of the storage of water in Ashokan reservoir, October 11, 1913. Source: NYPL Digital Collections. Link.

A bird's eye aerial black and white photo of the Ashokan Reservoir with a mountain range in the background. The body of water in the middle, and man-made circular structure and landscaped features in the foreground. A bridge stretches across from the foreground land to another edge of the water on the right. — Aerial view of Ashokan Reservoir in New York. In the foreground are several houses and a park-like area among the trees. On the right, roads lead around the reservoir and to a bridge or dam that crosses the reservoir at a narrow point. The Catskill Mountains loom in the distance. 1933. Source: New York State Archives. Link.

A satellite image of New York State zoomed out so you can see almost all of Long Island, and most of New York State. — Google Earth images of the Ashokan Reservoir. March 2021.
Source: Google Earth.

Another satellite image of New York State, slightly more zoomed in than the preceding image. You can mostly just see green topography and you can barely make out a dark blue shape that is the Ashokan Reservoir.

A satellite image that frames the Ashokan Reservoir and the topography of the Catskill Mountains that surround it. Like the images that precede it, it is mostly green forest, topography, and a dark blue form that represents the water.