Assessing Utility Vulnerabilities to Climate Change: New York City Pilot Study

Over the past decades a standard analytical template has emerged to support long-term water management planning. The first step involves estimating a future level of water demand in response to a projection of future demographic and economic patterns. In the second step, planners define near-term actions that would ensure that the water system could meet the anticipated demand under the worst conditions in the historical period (i.e., safe yield). In systems characterized by multiple water users pursuing varied objectives, the framework also considers the performance of different strategies against other management objectives such as aquatic ecosystem protection, hydropower production, flood protection, recreation, etc.

Climate change adds a layer of complexity to the already substantial challenges facing water utility managers. As future conditions become increasingly less certain, decision processes responding to these changes are necessarily evolving away from a deterministic prediction-based paradigm to one based on vulnerability identification and adaptation planning. A planning processes serious about addressing climate change must (1) acquire and/or develop data describing the link between potential future climate conditions and risk (Risk Identification), (2) modify analytical frameworks to assess the impact of different climate regimes on desired system outcomes (Risk Assessment), and (3) adopt a decision analysis framework that can evaluate adaptation strategies against climate-related risks (Risk Management). A fortunate corollary of such a process is that it also places water utilities in a better position to respond to other planning uncertainties beyond those related to climate change (e.g. demographic change, regulatory change).

In response to the changing conditions for water managers due to climate change, the Water Research Foundation commissioned the project “Vulnerability Assessment and Risk Management Tools for Climate Change: Assessing Potential Impacts and Identifying Adaptation Options.” The goal of the project is to develop a framework for assisting “water utilities in identifying and managing risks associated with potential impacts from climate change.” As part of the project the methodology will be tested by New York City Department of Environmental Protection (NYCDEP) and Colorado Springs Utilities. This presentation will describe the NYCDEP pilot test of the climate change vulnerability methodology, including the scenarios evaluated, projected future climate data input, modeling tools utilized, and adaptation options analyzed. This presentation will provide the audience substantial insight into an applied climatology project being conducted for the primary benefit of drinking water utilities.