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February 2, 2011


Farrell Sklerov / Michael Saucier (718) 595-6600

DEP Hosts Expert Workshop to Review New System to Improve Reservoir Management

Top Water Scientists, Academics and Water Suppliers Provide Technical Expertise on Use of Operations Support Tool, a Cutting Edge Water Supply Computer Modeling System

The New York City Department of Environmental Protection today conducted a workshop with some of the nation’s top water scientists, academics, engineers and water supply experts to solicit technical review of the Operations Support Tool (OST), a cutting-edge, $5.2 million integrated monitoring and modeling system that will enable DEP’s water supply operators to more accurately predict water storage levels in the city’s reservoirs so that DEP can better manage the movement of water throughout the reservoir system, and ultimately, to the nine million New Yorkers who rely on the city’s drinking water every day. The workshop, held over the last two days at the Frost Valley YMCA facility in Claryville, NY, featured panel members who provided technical expertise to DEP to ensure that the science behind the OST is sound and to provide guidance for future use.

“Seeking input from some of the most respected experts in water resources management will help ensure that we truly optimize the Operations Support Tool for the benefit of our nine million customers, as well as our state and federal partners,” said Commissioner Holloway. “The OST is cutting-edge technology that provides real-time information on inflow data, water quality, forecasting, reservoir storage levels and other factors. It will substantially increase our operational responsiveness, and our ability to protect water quality and improve the aquatic habit below our reservoirs. This new technology is already paying dividends: DEP has already committed to making clear water releases from Ashokan Reservoir into the lower Esopus Creek for the first time ever, and we have submitted a proposal to the Delaware River Commission to increase our releases from the Delaware watershed to the downstream communities that also rely on its water. I would like to thank all of the workshop participants for their vision and valuable feedback.”

“Based on our joint experience we applaud this pioneering, innovative effort to apply the latest water science and technology to adaptively manage water utility service,” said Kyle Schilling, former director of the U.S. Army Corps of Engineers, Institute for Water Resources and John Schaake, former senior scientist and deputy director for the office of hydrology at the National Weather Service. “This project will improve the reliability, quality, and economic efficiency of New York City’s water supply. It will enable the City to respond effectively to changing weather, climate, and emergency events. It will offer new opportunities for managing risk, improving the environment, and maintaining an aging infrastructure.”

“The flexibility and forecasting capabilities of the OST will enable the City to improve the operations of its dams on the Delaware to the greater benefit of the river’s aquatic ecology, and indeed of all the river’s stakeholders,” said Peter Kolesar, professor emeritus at Columbia University, and a member of the Water Center of Columbia’s Earth Institute and one of the principal architects of the Delaware River Basin Commission’s Flexible Flow Management Plan.

“Water supply utilities must look toward science and technology to improve operations to reduce cost and improve reliability,” said Dr. Alison Adams, a supply rotation and environmental protection manager for Tampa Bay Water, the largest wholesale public water supplier in the state of Florida. “We have to make the most of the infrastructure that is in place and not rely on additional supplies. The OST will provide the City with the tool needed to manage the area’s water resources.”

“This workshop provides a unique opportunity to bring the OST developers together for an independent technical review and help advance the state of the practice in water resources management,” said Dr. Robert Annear, a water resources engineer with Geosyntec principally involved in hydrodynamic and water quality modeling.

“The Operations Support Tool, that was discussed at this workshop this week, is a major step forward showing the vital signs of the New York City water supply and system of 19 reservoirs allowing operators to measure the pulse, status and forecast the state of the system using predictive algorithms and through a network of real time sensors,” said Dr. James S. Bonner, a Shipley fellow and professor of civil engineering at Clarkson University and a nationally recognized expert in real-time water monitoring technologies. “This represents a major improvement and enhances capacity to manage the water supply insuring adequate water and superior water quality for NYC residents.”

Other experts who attended the workshop included:

  • Dr. Robert M. Hirsch, former chief hydrologist and currently a research hydrologist at the U.S. Geological Survey.
  • Stephen Estes-Smargiassi, director of planning at the Massachusetts Water Resource Authority.
  • Dr. William Taylor, team leader of the Reservoir Management Team at the Metropolitan Water District of Southern California.

The Operations Support Tool will link DEP’s water quality and quantity models; assimilate near-real-time data on reservoir levels, stream flow into the reservoirs, snowpack and water quality in streams and reservoirs; and ingest National Weather Service forecasts. At the same time, it will apply the rules and laws that govern the water supply operations.

Already, DEP has used the OST to improve the way it operates the city’s reservoirs. Last month, DEP agreed to use the Ashokan Release Channel to release clear, high-quality water into the lower Esopus Creek for the first-time ever, which will help address some of the concerns raised by interested groups in the lower Esopus. This new initiative is made possible because of OST, which allows better prediction of reservoir-specific water storage levels, quality, and inflows, which gives DEP a level of certainty that was not previously possible about when it is safe to release water without unnecessarily depleting the water supply of nine million New Yorkers. DEP is currently developing a new plan whose goal is to make better use of the shared water in the Delaware River Basin. The plan will divert or release water from each of its reservoirs at times that will improve protection of downstream habitat and help cushion storm impacts, while still ensuring a reliable supply of high quality water for New Yorkers.

Last February, Commissioner Holloway announced that work had begun on the OST, the first of its kind in the world. The OST will improve the City’s water management systems by predicting events that could affect water quality much earlier than is possible now, and incorporating more data in the models used to determine water flows. Understanding the volume and quality of the reservoirs and their feeding waters (rivers, streams, etc.) is critical to isolating and addressing cloudy water that can affect overall quality. The system is expected to be complete by 2013 and will be phased in on a rolling basis. The consultant for the initiative is Hazen and Sawyer.

DEP manages the city’s water supply, providing more than 1 billion gallons of water each day to more than 9 million residents, including 8 million in New York City, and residents of Ulster, Orange, Putnam and Westchester counties. Approximately 1,000 DEP employees live and work in the watershed communities as scientists, engineers, surveyors, and administrative professionals, and perform other critical responsibilities. New York City’s water is delivered from the Catskill, Delaware, and Croton watersheds that extend more than 125 miles from the City, and comprises 19 reservoirs, and three controlled lakes. For more information, visit or follow us on Facebook at

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