Consensus Report

Review of the New York City Department of Environmental Protection Operations Support Tool for Water Supply (2018)


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New York City's water supply system is one of the oldest, largest, and most complex in the nation. Managed by the New York City Department of Environmental Protection (NYC DEP), the system delivers more than 1.1 billion gallons of drinking water each day from three upstate watersheds (Croton, Catskill, and Delaware) to meet the needs of over nine million people in New York City and its surrounding counties.

In response to evolving permitting requirements and storm events, the NYC DEP developed the Operations Support Tool, a computer model that incorporates data and information on dozens of variables such as precipitation, temperature, streamflow, water demand, and operations of the water supply system. The tool helps water managers optimize the timing and volume of water releases from reservoirs to manage turbidity levels, enhance ecological conditions in downstream systems, and maintain delivery of high quality drinking water.

This review of the Operations Support Tool finds that the tool offers a dynamic water routing platform that is both adaptable and capable of continuous improvement, if properly resourced with data, validated, and continually maintained.