Integrating Climate Resilience into Washington State Water System Planning

Abstract

Through a systematic review of existing water system plans and case study analysis, we explored if and how Washington state’s water system planning process could be a mechanism for climate resilience planning among small drinking water systems. Under Washington state rule WAC 246-290-100, Group A Community Systems with 1,000 or more service connections are required to periodically develop and gain approval for a Water System Plan (WSP) from the Department of Health’s Office of Drinking Water to demonstrate 1) system capacity to provide safe and reliable drinking water and 2) how the system will address present and future needs in a manner consistent with other relevant plans and local, state, and federal laws. To achieve this, WSPs are required to develop demand forecasts and a source supply analysis for at least a twenty-year planning period. Although an assessment of future climate impacts is not directly required, the requirement to develop future demand forecasts and a source supply analysis is an opportunity to consider the long-term effects of changes in the climate on demand and the quantity and quality of water sources. WSPs are also used by the State to determine drinking water system eligibility for low-interest financing of climate resilience projects and the Drinking Water State Revolving Funds, which can provide systems with funding for emergency response to climate-related hazards.