1. THE PARADOX OF WATER SCARCITY IN A WATER RICH REGION Anne Nolin and the Willamette Water 2100 Team December 4, 2015 water.oregonstate.edu/ww2100 Painting: Courtesy of April Waters, used with permission 1

2. About these Slides 2 The following slides are from a presentation given by Anne Nolin at the Willamette Water 2100 Capstone Workshop on December 4, 2015. These slides represent work in progress and can be used in presentations with attribution, but should not be cited as final work. Nolin, Anne W. and the Willamette Water 2100 Team (2015, December 4) The Paradox of Water Scarcity in a Water Rich Region. Presentation at the Willamette Water 2100 Capstone Workshop, Salem, Ore. Retrieved from http://water.oregonstate.edu/ww2100/capstone-workshop This project is supported by the National Science Foundation under Grants No. 1039192, 1038925 and 1038899. Any opinions, findings, and conclusions or recommendations expressed in these slides are those of the authors and do not necessarily reflect the views of the National Science Foundation. Willamette Water 2100 – December 4, 2015

3. Overview statement One of the key findings from our project is that despite being a water-rich basin, we expect wide variation in the future scarcity of water across different seasons, locations, qualities (e.g., temperature), and uses. 3Willamette Water 2100 – December 4, 2015

4. Climate Climate models indicate that temperatures will continue to rise. Winter precipitation may increase slightly and summer precipitation is likely to decrease. 4Willamette Water 2100 – December 4, 2015

5. Water Scarcity: Let’s be clear Water scarcity can arise due to two main factors, the costs of storing and transporting water, and the effectiveness of the institutions that govern its use. There is quantitative and qualitative scarcity. 5Willamette Water 2100 – December 4, 2015

6. Future Scarcity in the Mountains 6 Warmer winters reduce snowpacks by 63-95% Willamette Water 2100 – December 4, 2015

7. Impacts on Upland Forests Low snowpack and hotter/drier spring and summers leads to a 200-900% increase in forest wildfires in our simulations. Mountain ecosystem water use declines. 7 Total Area Burned Willamette Water 2100 – December 4, 2015

8. Vegetation Shifts Fire opens up lands to transition to new forest types and reduces the availability of forestland for timber harvest 8 Willamette Water 2100 – December 4, 2015

9. Future Scarcity in the Valley Water scarcity in the valley will more likely be due to changes in economics and demographics, as well as the institutions and infrastructure available (e.g., reservoirs, technologies, etc.) rather than direct, yet substantial, impacts of climate change 9Willamette Water 2100 – December 4, 2015

10. Agricultural Water Irrigation withdrawals from surface water sources are likely to decline 5% over the 21st century, due to urban expansion onto farmland 10Willamette Water 2100 – December 4, 2015

11. Urban Expansion and Water Providing water for a doubling of the basin’s population will involve expansion in costly water supply infrastructure. Our projections suggest a doubling of urban water demand from 300,000 acre-feet per year to more than 600,000 acre-feet. In our High Population Scenario, demand rises to 1 million acre-feet per year. 11Willamette Water 2100 – December 4, 2015

12. 12 Our projections indicate that 99% of this increased demand can be satisfied with existing municipal water rights. Urban users are more likely to experience “water scarcity” in terms of its price (distribution costs due to expanding urban areas) Willamette Water 2100 – December 4, 2015

13. Water Temperature and Fish For a 2°C increase in water temperature, the likelihood of occurrence of native cold- water fish would decrease significantly 13 colder water warmer water present-day +2°C colder water warmer water present-day +2°C Willamette Water 2100 – December 4, 2015

14. Consumptive Water Use Consumptive use is water that is used by vegetation, where evapotranspiration shifts water from soil to the atmosphere. Non-consumptive water use is predominantly urban indoor water use (e.g., piped water) that is returned to surface flow. Future consumptive use of surface water for irrigated farmland will remain high relative to consumptive use of surface water in urban areas; some subbasins will see a net reduction in consumptive use because of urban development of currently surface irrigated farmlands. 14Willamette Water 2100 – December 4, 2015

15. Urban water use (in-basin) overtakes agricultural water use as population grows 15 Willamette Water 2100 – December 4, 2015

16. Summary  Significant climate-driven water scarcity impacts in the mountains with losses of winter snowpack, large increases in wildfire, and shifts in vegetation type  Urban expansion, economics, policy & governance affect water scarcity in the valley with varying impacts on agriculture, urban, and consumptive water uses  Climate warming and land use change affect instream flows and stream temperature both of which play a significant role in water management because of requirements for threatened and endangered fish 16Willamette Water 2100 – December 4, 2015