The 100 Year Plan for Ashokan Reservoir
We have officially launched the Ashokan Century Program, a $750 million plan to upgrade water supply infrastructure at Ashokan Reservoir. The comprehensive, multi-year capital program will include upgrades to the dam, dikes, chambers and other facilities at Ashokan Reservoir, which has provided clean drinking water to all five boroughs of New York City for exactly 100 years. The program — which comprises the largest public works project in the Catskills in more than 50 years — was officially funded this month in New York City Mayor Bill de Blasio’s capital budget.
The program will include upgrades to practically every piece of infrastructure that impounds or conveys water at Ashokan Reservoir, along with a bridge and a historic monument. Construction of the projects is expected to begin sometime around the year 2023. Engineers will begin to design the project next year. Later this summer, local residents and visitors should expect to see some preliminary construction and investigation work that will gather information needed for the design process. This will include soil and bedrock sampling, infrastructure inspections and other analyses. Exact details on each project will not be available until the design work is completed. Work on the myriad projects that comprise the Ashokan Century Program is expected to last approximately 10 years.
The Ashokan Century Program will include the following work:
• Olive Bridge Dam and Ashokan Reservoir dikes: DEP will perform a number of tasks at the Olive Bridge Dam and the many dikes that impound water at the reservoir. This will include structural upgrades, the installation of modern drainage and monitoring equipment, and the clearing of undesirable vegetation. The dam and dikes at Ashokan Reservoir total approximately 29,000 linear feet, more than the dams of all New York City’s other drinking water reservoirs combined.
• Ashokan Reservoir spillway: DEP will reconstruct the spillway and spillway channel.
• Dividing Weir Bridge: The bridge that carries Reservoir Road over Ashokan will be completely reconstructed. The new bridge will include two travel lanes, shoulders, and a pedestrian/bike lane that will connect DEP’s existing walkway on the south side of the reservoir with the future rail trail being developed by Ulster County.
• Ashokan Reservoir headworks: The headworks are three masonry buildings that contain valves, gates and tunnels that convey water from Ashokan Reservoir into the Catskill Aqueduct. Under this program the superstructures will be rehabilitated, and many of the gates and valves will be replaced with modern equipment.
• J. Waldo Smith Monument: The monument was used as a triangulation tower during construction of Ashokan Reservoir, allowing surveyors to take thousands of accurate measurements. The stone tower was later rededicated as a monument to J. Waldo Smith, the chief engineer who oversaw construction of the entire Catskill Water Supply System. The monument and its adjacent lands will be rehabilitated as a central location for public education and recreation.
The Ashokan Century Program is part of DEP’s continuing efforts to upgrade dams and other key facilities that provide 1.1 billion gallons of drinking water every day to 8.5 million people in New York City and another one million people in four counties north of the City. That effort began nearly three decades ago. Beginning in the 1990s DEP rehabilitated a number of dams that are part of its Croton Water Supply System in Putnam and Westchester counties. In 2014, DEP completed the $138 million full-scale rehabilitation of Gilboa Dam at Schoharie Reservoir. DEP continues to work on other elements of the upgrade program at Schoharie Reservoir, including the construction of a new release works and a rehabilitation of the reservoir’s intake chamber.
Ashokan Reservoir provides about 40 percent of New York City’s drinking water each day. It impounds 128 billion gallons of water at full capacity. The reservoir collects rainwater and melting snow from a 255-square-mile watershed that includes part of 11 towns in Ulster, Greene and Delaware counties. The reservoir conveys that drinking water to New York City through the 92-mile Catskill Aqueduct.
The Ashokan Century Program underscores New York City’s commitment to keep its water supply infrastructure in a state of good repair for generations to come. More than 100 years ago, a group of public servants and brilliant engineers set out with a clear goal — to build the greatest water supply in human history. When construction of the Catskill Water Supply System was completed, those same engineers recapped their work in a report that said the system could last for ages if its infrastructure was monitored and periodically upgraded. The Ashokan Century Program heeds the advice of those who built the water supply, and it makes good on our mission to protect public health and safety long into the future.
