Water Supply Modeling and Analysis—New York City

Water Supply Modeling and Analysis

The Situation

To provide the approximately 1.5 billion gallons of water per day required by nearly 10 million residents, New York City decided to maximize the yield of its water supply system. The system is notably complex: It includes 19 reservoirs stretching from the Catskills to the Croton to the Delaware River Basin and is governed by three states in conjunction with a River Master, a position instituted by the US Supreme Court.

New York City selected GKY to evaluate their operations, provide tools for testing alternative system operating strategies, and recommend operating rules in order to stretch system yield.

The Solution

GKY developed a custom simulation model, as no off-the-shelf tool could accurately simulate all the system’s complex operating rules – designed to serve a triad of states (Delaware, New York, and Pennsylvania).

GKY used the model to assess system yield under current procedures and compare it to alternative strategies. We also developed an optimization model using the General Algebraic Modeling System (GAMs), cost-effectively producing additional strategies for improving system yield.