Publications

Climate Change, Sea Level Rise, and Flooding in the Lower Snohomish River Basin

Citation

Mauger, G. S., and S.-Y. Lee, 2014. Climate Change, Sea Level Rise, and Flooding in the Lower Snohomish River Basin. Report prepared for The Nature Conservancy by the Climate Impacts Group, University of Washington, Seattle.


Abstract

Over the past decade, numerous climate change assessments have estimated changes in river flooding, sea level rise, and storm surge. Few, however, have quantified the joint impacts of both on future changes in flood risk. The lower mainstem of the Snohomish River is impacted from the marine side by storm surge and sea level rise (SLR), and from the freshwater side by seasonal changes in river flow and hydrologic extremes. We assessed the impacts of climate change on sea-level rise, storm surge and peak streamflows in the lower Snohomish River, located in the Puget Sound Region of Washington State (Figure 1). Building on previous work in the Skagit River basin (Hamman et al., 2014; Hamman, 2012), we developed projections of changing inundation in the lower Snohomish. Results from this work have been incorporated into a decision support tool developed by The Nature Conservancy (TNC), designed to support multi-objective floodplain management by partners across Puget Sound.