Kensico Reservoir

The Kensico Reservoir is a reservoir located in Valhalla, New York that was put into service in 1915. It is about 3 miles (4.8 kilometres) north of White Plains, New York, and about 15 miles (24 kilometres) north of New York City. It was formed by impounding the Bronx River, but receives most of its water from other places. For instance, it also shares water with Rye Lake, which is separated from the Kensico Reservoir by Great Island, an island in the middle of the lake/reservoir that used to be the top of a mountain. Along with the West Branch Reservoir and Boyds Corner Reservoir, it is one of only three reservoirs within the Catskill/Delaware system that is not in the Catskill Mountains region.

History

As the population of New York City grew in the 19th century, so did the need for water. The first use of water from Westchester County came from the old Croton Dam (forming what was called "Croton Lake"), which was completed in 1842. In the 1880s, the City faced increasing demands for water and therefore needed to enlarge the Croton Reservoir to meet that need. The enlargement of the Croton Reservoir (with the construction of the "New Croton Dam" and the forming of the "New Croton Reservoir") was completed in 1906 as a part of a system of reservoirs designed to bring water from Putnam and Westchester Counties (the Croton Watershed) to New York City.

In 1885, the Kensico Dam was built south of the village of Kensico, NY as an additional source of water for New York City. A granite dam formed a small lake from water supplied by the Bronx River and the Byram River, but it was still not enough for the ever-increasing population of New York City. A reservoir was needed that would contain waters from various new reservoirs and act as a holding tank for distribution to New York City.

The village of Kensico, NY was surrounded by hills that came to a natural V-shape. There was also a nearby quarry on Silver Lake, in North Castle, making the town a logical site for the new dam. Although relatively small--with a population of about 200 people--Kensico had houses, stores, churches, hotels and a railroad station.

In 1905, legislation was passed by New York State to allow money to be raised for the building of the Kensico Reservoir. The next year, final planning by the state was approved, and preliminary surveys were started. Seventeen miles of railroad track were privately built to carry materials from quarries at nearby Cranberry and Silver Lakes to the dam site; this spur railroad and a highway network had to be built to move supplies into place. A camp for the workers and their families had to be constructed, along with facilities such as schools for their children.

To prepare for the dam construction, each individual lot of land was condemned and appraised, and the owner paid a "fair value" for the land. Many of the families had to move to such surrounding towns as Valhalla, Armonk and White Plains. The village of Kensico was then flooded to make way for the dam.

Construction

The actual construction of the dam began in 1913 and was concluded in 1917--three years ahead of schedule--at a cost of more than $15,000,000. The dam is long. It stands above its foundation and contains of masonry--as much masonry as the Egyptians used to build some of the pyramids. In one month, 2.5 million cubic yards of concrete were poured into blocks, which had to cure for three months before being swung onto the rising hyperbolic pile of dam. The dam is able to hold back about 30 billion gallons of water.

Frank E. Winsor was the engineer in charge of construction of Kensico as well as Hillview Reservoir and of the Catskill Aqueduct.

New York City’s main contractor built a work camp at nearby Valhalla for the 1,500 men who worked on the dam at the height of construction. The water supply board created a mounted police force to keep order. Crews were made up of largely Italian immigrants who began the long task of digging straight down to a depth of to reach solid rock with no water-bearing seams. This entailed months of blasting and a number of fatal accidents. As the aqueduct neared completion in 1913, the work gangs at Kenisco began laying the first of the concrete bricks of which the dam is built.

The tremendous influx of workers provided a period of prosperity for the surrounding area. New stores, rooming houses, hotels, restaurants and saloons met the needs of the workers and their families. Many of the construction families remained in the area after completion of the dam, contributing to the growth and character of Valhalla and its environs. The Kenisco Reservoir was acquired as parkland in 1963 from the New York City Watershed Commission and remains the property of the New York City Department of Environmental Protection. Kensico Dam Plaza is a Westchester County Park.

Demographics

The reservoir is the collecting point for the water from all six reservoirs in the Catskill Mountains: the Ashokan Reservoir, the Cannonsville Reservoir, the Neversink Reservoir, the Pepacton Reservoir, the Rondout Reservoir, and the Schoharie Reservoir. It also receives water from the Croton Falls Reservoir, the Muscoot Reservoir, the New Croton Reservoir, and the West Branch Reservoir through the Catskill and Delaware aqueducts, along with water from Rye Lake.

The resulting body of water has a drainage basin of only 13 square miles (20.8 square kilometers), and holds 30.6 billion gallons (115.8 million m³) of water at full capacity. The reservoir itself provides only 2% of NYC's water supply; the rest of the water comes from the reservoirs to which it connects. The water in the reservoir either provides NYC with water, or it travels down the spillway at the southernmost dam, and continues down the rest of the Bronx river, eventually flowing to the East River.

The water that does supply water to New York City travels down either the Catskill Aqueduct or the Delaware Aqueduct. If it goes down the Delaware Aqueduct, it will pass through Yonkers, and flow through the Hillview Reservoir. It then continues through The Bronx, Manhattan, Brooklyn, and then stops at Staten Island. If it flows through the Delaware Aqueduct, It will stop at the Hillview Reservoir, and continue on through The Bronx, Queens, Brooklyn, and then stop at Staten Island.

Dam Restoration

In 2006 the New York City Department of Environmental Protection (DEP) began a $31.4 million project to rehabilitate the Kensico Dam, including restoration of the decorative stonework and spillways. The project is expected to be completed by January 2007.

See also

• List of reservoirs and dams in New York

External links

• Short film (1920s) containing views of the Kensico Dam
• Westchester County official website for Kensico Dam Plaza