2014/07/16 Council Agenda Packet

Potential impacts from climate change include: • Sea level rise from warming of the ocean and melting of glaciers • Floods • Droughts • Wildfires • Increase in frequency and severity of storms and other weather events • Extinction of species • Impacts to crop yields • Impacts to water availability and quality • Impacts to human health ■ Environmental justice issues Specific to Washington State and the central Puget Sound region, potential impacts include: • Milder winters and warmer summers • More rain and less snow between October and March ■ Declining water supplies between July and October • Changes in growing seasons and other impacts to crops from severe weather events and a lack of water ■ Increased smog and respiratory ailments • Declines in salmon, native plants and wetlands • Sea level rise This paper does not address the potential impacts from climate change to sectors other than transportation, which are included in whole or in part in the 2009 UWCIG's assessment report and in orrgoing work conducted by Ecology. This paper focuses solely on potential impacts from climate change on transportation infrastructure in the central Puget Sound region. These potential impacts could include: ■ Accelerated deterioration of roadways • Flooding of roadways and increased stormwater issues • Storm surge damage to docks and other facilities • More frequent landslides • Bridge damage from storms, and structural degradation of bridge materials • Rail buckling from higher temperatures • Reduction in aircraft lift and efficiency due to higher temperatures • Reduced water levels affecting ships and barges Perhaps the largest potential threats — or at least those most visible - from climate change to transportation infrastructure in the central Puget Sound region are those of sea level rise and increased flooding. These issues will be more fully addressed in Sections 3 and 4. SECTION 2: CENTRAL PUGET SOUND REGION The central Puget Sound region is a diverse geographic area with a population of over 3.5 million people. The region is bordered by two mountain ranges, lowland river valleys, and deep marine basins within Puget Sound. The region is also geologically active, and contains many fault zones. The Transportation 2040 Environmental Impact Statement contains more detailed information on the region's geography, hydrology and other baseline environmental conditions, but a few topics that are relevant to a discussion of potential impacts from climate change are summarized below. Hydrology and Floodplains The region has a rich array of water resources, including rivers, streams, lakes, wetlands, estuaries, as well as Puget Sound. The region contains all or part of nine large watersheds: the Upper Skagit, Stillaguamish, Snohomish, Cedar/Sammamish, Green/Duwamish, Puyallup/White, Nisqually, Chambers/Clover and Kitsap Water Resource Inventory Areas. Some of these watersheds, as well as groundwater aquifers, supply the region's drinking water. L-14 Appendix L: Climate Change Background