Hydrology and Water Resources: Current Research
Climate Change Impacts on Urban Water Supplies
Climate change impacts on urban and suburban water supplies have the potential to affect a significant portion of the Pacific Northwest's (PNW) population. According to a recent report from Northwest Environment Watch, more than 50% of the region's population (including British Columbia) is concentrated in the seven most populous metropolitan areas of the PNW (The Cascadia Scorecard, 2004).
The Climate Impacts Group (CIG) is involved in several consultancy-based climate change studies for PNW urban water supplies. These projects, which are typically funded by utilities, draw on climate change research and methodologies developed by CIG researchers.
- Richard Palmer, CIG and UW Civil Engineering
- Portland (Oregon) climate change study (Palmer and Hahn 2002) - Climate change impacts on supply and demand in the City of Portland are expected to have a considerable cumulative impact on water supply availability. By the decade of the 2040s, climate change could require that Portland provide additional water totaling 50% of the amount that would otherwise be required to meet population growth alone in that same period.
- Tualatin River (Oregon) climate change study (Palmer et al. 2004) - For municipal and agricultural water supply in the Tualatin River Basin, climate change is expected to reduce system yield by 1.5% per decade over the next 40 years even as demand increases. This reduction advances the need for system expansion by 5 to 8 years. The Tualatin Basin will also see decreases in summer streamflow on the order of 10-20%, stressing the system's ability to meet streamflow temperature requirements and instream flow needs. The impact of extended drought may also be much more significant.