The Southern Nevada Water Authority – a cooperative of seven water and wastewater agencies – serves more than two million residents in Nevada, including the city of Las Vegas. The Water Authority worked with the U.S. Environmental Protection Agency's Creating Resilient Water Utilities program to conduct a vulnerability assessment of the Las Vegas service area that considered climate impacts and vulnerabilities in two future scenarios: in 2035 and in 2060. Projected climate impacts included hotter and drier summers, drought conditions and increased algal blooms.
This vulnerability assessment also helped identify more than 60 potential current and future actions to take in response to and prepare for climate change. The Water Authoriy followed up this initial analysis with a more in-depth assessments of water source availability under future climate change, population and water demand projections. These assessments provide the Water Authority with a better understanding of its climate risks and potential vulnerabilities. The information also informs the water authority’s ultimate consideration, selection and implementation of appropriate adaptation strategies. The Water Authority continues to anticipate, prepare and plan for the future as a member of the Water Utility Climate Alliance, a consortium of 10 of the largest water utilities around the country actively engaged on climate change.
To start, the Southern Nevada Water Authority identified projected climate risks and assessed utility vulnerability. Using USEPA's Climate Resilience Evaluation and Awareness Tool, the Water Authority analyzed a range of climate projections for the Las Vegas area through 2035 and through 2060.
Projections from the Climate Resilience Evaluation Awareness Tool helped identify the most vulnerable assets and assessed the facility assets against their respective climate threat. These asset/threat pairings were used to help identify potential cost-effective adaptation strategies. The analysis identified resilience and adaptation actions, and developed “adaptation packages” of strategies that were scaled to the magnitude of scenario risk. For example, resilience strategies for the short and long-term threat from harmful algal blooms included increasing water quality and temperature modeling, while adaptation options included altering the water treatment process or extending source water intake levels deeper.
The Water Authority used their analysis to identify initial assessment limitations and realized the need to conduct further analysis before implementing adaptation strategies. The Water Authority understood the limitations of the first study and undertook a follow up analysis that used refined scenarios, which included more locations and encompassed a greater focus on water availability and quality concerns (e.g., dissolved oxygen, turbidity, and mixing).