History of the East of Hudson Watershed

West Branch

Constructed in 1895 via the impounding of the West Branch of the Croton River, the West Branch Reservoir is located in the towns of Kent and Carmel and its waters span an area of 1,061 acres. The reservoir acts mainly as a settling basin for the incoming flow to ensure that any large sediment is removed. The inbound water comes from the Rondout Reservoir in the West of Hudson Watershed and during times of low flow or drought, from Lake Gleneida, which is a controlled lake. At peak capacity, the West Branch can hold up to 8 billion gallons of water and flows out to the Delaware Aqueduct.

Middle Branch

Located in the town of Southeast, the Middle Branch reservoir was created in 1878 via the damming of the Middle Branch of the Croton River. This reservoir has a water surface area of 395 acres and can hold up to 4.1 billion gallons of water at full capacity. Water flows from this reservoir into the nearby Croton Falls Reservoir.

Bog Brook

Built in 1892 in the town of Southeast through the impounding of the Bog Brook, this is a 379 acre reservoir which has a capacity of 4.4 billion gallons of water. It mainly serves as a storage reservoir to feed into the East Branch Reservoir.

East Branch

To collect flows from the Bog Brook, the East Branch Reservoir was constructed in 1891 by blocking up the East Branch of the Croton River. It is located in the town of Southeast, has a surface area of 525 acres and can hold up to 5.2 billion gallons of water. This reservoir is connected to the Bog Brook Reservoir via a large underground tunnel and is one of two double reservoir systems in the NYC water system. Construction of this reservoir required the leveling and flooding of the town of Southeast Center along with the village of Milltown. If you stop by the reservoir during a period of drought, you can even see old building foundations, property line rock walls and roadbeds! Water flowing out of this water body moves its way into the East Branch of the Croton River and onto the Diverting Reservoir.

Diverting

Also located in the town of Southeast, the Diverting Reservoir was constructed in 1911 and has an area of 126 and holds up to 900 million gallons of water. Water comes in from the East Branch/Bog Brook double reservoir system and flows out to the Croton Falls Reservoir. In 2007, the NYC Department of Environmental Protection began a huge overhaul project which included the implementation of new valves and pipes, a revitalized spillway and resurfacing of some portions of concrete along the dam. This project ensured that the dam will continue to deliver clean water with reduced amounts of water waste.

Croton Falls

Another reservoir located in the town of Southeast, Croton Falls was built in 1911 alongside the Diverting Reservoir. The West and Middle Branch of the Croton River were dammed to create a massive, three basin reservoir that can hold 14.2 billion gallon of water with a water surface of 1,062 acres. Water comes in via Lake Gilead, the West Branch, Middle Branch and Diverting Reservoirs, and then flows out into the Muscoot Reservoir. This Reservoir was also targeted as part of the 2007 revitalization project and received a deepened and widened spillway, dam wall resurfacing, a new bridge over the spillway and cable tie downs to anchor the dam to the bedrock.

Lake Gilead

Originally named Dean Pond, this small, controlled lake has a water surface of 118 acres and feeds the Croton Falls Reservoir during times of low flow. It has a remarkable depth of 120 feet at its deepest section and a dam on the southeastern end which controls the flow of water.

Amawalk

The Amawalk Reservoir is located in the town of Somers and spans an area of 564 acres, allows for storage of up to 6.7 billion gallons of water. This reservoir was built in 1897 through the damming of the middle of the Muscoot River and forced the flooding and relocation of the original village of Amawalk, which is where this reservoir gets its name. The Amawalk receives water from Kirk Lake, which is the third and last controlled lake in the Croton Watershed, and sends water out to the Muscoot Reservoir.

Muscoot

Located at the intersection of several town lines, the Muscoot Reservoir is one of the longest and largest reservoirs in the watershed with a shore length of 30.5 miles and a water surface of 1,263 acres which allows It to hold 4.9 billion gallons of water. However, the Muscoot wasn’t always so large. The original dam was constructed to impound the Muscoot River and created a much smaller lake. As water demand increased in New York City, a larger dam was constructed in 1905 which now serves as a collecting point for most of the reservoirs in the Croton Watershed.  Water that leaves the Muscoot drains to the New Croton Reservoir, which is the final stop before trekking on to the City.

Titicus

Construction on the Titicus Reservoir completed in 1893, which formed a body of water with a surface of 681 acres and a capacity of 7.2 billion gallons of water. This reservoir is located in the town of North Salem and receives flow mainly from the Titicus River and via sheet flow from the drainage area. Water exits the reservoir and flows into the nearby Muscoot Reservoir.

Cross River

The Cross River Reservoir, constructed in 1908 by impounding the Cross River. With a water surface of 915 acres, a maximum depth of 120 feet and a capacity of 10.3 billion gallons of water, this reservoir is one of the biggest. It is located in the towns of Bedford, Lewisboro, and Pound Ridge. Water primarily flows in from the Cross River and flows out to the Muscoot Reservoir.

New Croton

Home of one of the most beautiful dams in New York State, the current New Croton Reservoir was built in 1905, which replaced the Old Croton Dam. The original dam was completed in 1842 and was the first dam in the United States to be primarily constructed of masonry. However, with populations come greater water demands, which led to the implementation of the New Croton Dam at a staggering 2,182 acre water surface and a capacity of 19 billion gallons of water. This reservoir acts as a collecting basin for the entirety of the Croton Watershed and gathers all of the previous watersheds to send them down to New York City via the New Croton Aqueduct which ends up in the Jerome Park Reservoir in The Bronx.

Kensico

The final reservoir in the East of Hudson Watershed is the Kensico. It is located in the town of North Castle and was constructed in 1885 by the damming of the Bronx and Byram rivers with an earthen dam. In 1915, a new masonry dam was constructed that increased the capacity and added piping to bring water from the Catskill and Delaware Watersheds, but also flooded and displaced the village of Kensico. The newer reservoir has a surface area of 2,145 acres, a maximum depth of 144 feet and a mind-boggling capacity of 30.6 billion gallons of water at full capacity. Given that this is the last stop before sending a vast amount of water into New York City, the Kensico Reservoir is subject to federal water quality standards in coliforms and turbidity to ensure water health and safety.

This reservoir is the final terminal which gathers water from the Ashokan, Cannonsvile, Neversink, Pepacton, Rondout, Schoharie, Croton Falls, Muscoot, New Croton, and West Branch reservoirs, before flowing down either the Catskill or Delaware Aqueducts. The Delaware Aqueduct makes stops along the way in Yonkers at the Hillview Reservoir, The Bronx, Manhattan, Brooklyn and ends at Staten Island. The Catskill Aqueduct also makes a pit stop in the Hillview Reservoir before going through The Bronx, Queens, Brooklyn and ending in Staten Island.