The New York City Department of Environmental Protection (DEP) has developed an Operations Support Tool (OST), which is a combined water quantity and quality model, to help predict future water level and quantity conditions in the City’s reservoir system. This system extends roughly 125 miles north and west of New York City into rural and mountainous areas of New York State. The OST was developed to help the City determine optimal timing and volumes of water releases from large reservoirs in the system to help manage turbidity levels (particularly in water from the Ashokan Reservoir), enhance ecological conditions in downstream systems, and maintain delivery of high quality drinking water to over 8 million people.

An ad hoc committee of the National Research Council will review the Operations Support Tool and its many uses, and issue a report that addresses the following:

• The committee will review the City’s use of OST for water supply operations, including managing elevated turbidity, and will consider potential ways in which the City can more effectively use OST.
• The committee will evaluate the performance measures the City uses to assess the efficacy of the Catskill Turbidity Control Program, making recommendations for additional performance measures, if necessary.
• The committee will review the City’s plan for use of OST in evaluating proposed modifications to the Catalum State Pollution Discharge Elimination System permit, as well as alternatives to be considered in the associated environmental review.
• The committee will review DEP’s existing studies of the potential effects of climate change on the City’s water supply to help identify and enhance understanding of areas of potential future concern with regard to the use of OST.