Water is critical to life, and many of the effects of climate change on ecosystems are mediated through altered hydrology. Snow accumulation and melt are consistently cited as the most important changes to water in the western United States (Barnett et al. 2005; Service 2004), affecting when water will be available for forests, fish, and people. Changes in summer atmospheric circulation patterns may alter the ability of summer precipitation to provide a midsummer respite from seasonal drought and dampening of wildfire spread (IPCC 2013) (Chapter 8). Declining summer water contributions will challenge municipal and agricultural water supplies (Barnett and Pierce 2009; Dawadi and Ahmad 2012). Aquatic and terrestrial ecosystems - including riparian areas, wetlands, and groundwater-dependent ecosystems - will be affected by lower base flows (Kormos et al. 2016; Rood et al. 2008), earlier snowmelt (Luce et al. 2014), increased periods of drought (Cayan et al. 2009), increased sediment delivery (Goode et al. 2012), and higher midwinter floods (Goode et al. 2013). Soils will likewise be affected by increased temperatures and shifts in precipitation and hydrological processes, with effects on physical and biological processes and attributes of soils.