Abstract

Recent research suggests that future heavy rain events will be more intense in the Pacific Northwest (e.g., Warner et al. 2015). Past studies have not accounted for this change, either because the methods cannot reliably capture changes in rainfall intensity (e.g., Abatzoglou and Brown 2012), or because previous studies did not evaluate changes in short-duration precipitation (e.g., hourly) that are of relevance to stormwater planning (e.g., Salathé et al. 2010).

The purpose of this project was to develop projections of 21st century changes in precipitation that can be used to inform stormwater and wastewater management in the cities of Portland and Gresham, and Clackamas County.