Anacortes, Washington Rebuilds Water Treatment Plant for Climate Change

Recognized climate risk and expected vulnerability

• Anacortes recognized the vulnerability of the facility to flooding in 2003 and 2008, however, they also identified the cost-prohibitive nature of moving the facility.
• When upgrading the facility they received input from scientists and used downscaled climate data to inform decision making.

• The EPA Coastal Inundation Toolkit provides resources for practitioners and environmental professionals to prepare for anticipated climate risks to coastal areas and watersheds.
• The Hoosier Resilience Index allows you to learn about your area's climate impacts, evaluate your community's sensitivity, and prioritize actions to prepare.
• The ERI's adaptation strategies for risk and vulnerability assessments offer methods to address anticipated climate risks with risk and vulnerability assessments.

Incorporated projections of climate vulnerability within plant design to adapt to future conditions

• Developed a design that acknowledged the current vulnerability and sought to reduce future vulnerability under anticipated future conditions.
• Elevated critical facility structures and included ring dikes and dewatering pump systems to protect against flooding.
• Utilized watertight construction on the facility and used waterproof membrane below 40-foot elevation.
• Designed to have no/minimal penetrations below 100-year flood elevation and have electrical switchgear located above the 100-year flood level.
• Raised and strengthened levees near the plant.
• Increased sediment removal ability to deal with an expected increase from climate change (although the plant is still trying to quantify the projected increase of sediment).

• EPA's Creating Resilient Water Utilities Adaptation Strategies Guide
• The ERI's adaptation strategies for drinking water offer methods to address anticipated climate risks to drinking water.
• The ERI's adaptation strategies for flooding offer methods to address anticipated climate risks to water quality, infrastructure, and safety resulting from extreme storms and flooding.

Identified information gaps for future research

• Preliminary modeling suggests saltwater intrusion is likely to be a future concern; additional analysis is planned.
• Further research is needed to better understand the long term challenges associated with sediment loads.

• The Climate Resilience Evaluation and Awareness Tool (CREAT) is a risk assessment tool that helps utilities to adapt to extreme weather events by better understanding current and long-term weather conditions.