1. Strategies for Water Planning in an Uncertain Climate
JISAO/SMA Climate Impacts Group
and Department of Civil and Environmental Engineering
University of Washington
March, 2004
Alan F. Hamlet

2. People in the Climate Impacts Group
PI: Edward L. Miles (human dimensions)
Principals:
Robert Francis (aquatic ecosystems)
Dennis P. Lettenmaier (hydrology and water resources)
Nathan Mantua (climate dynamics)
Philip W. Mote (state climatologist)
Lara Whitely Binder (education and outreach)
Richard Palmer (water resources management)
David L. Peterson (forests)
Amy K. Snover (integration and synthesis)

3. Example of a flawed water planning study:
The Colorado River Compact of 1922
The Colorado River Compact of 1922 divided the use of waters of the Colorado River System between the Upper and Lower Colorado River Basin. It apportioned **in perpetuity** to the Upper and Lower Basin, respectively, the beneficial consumptive use of 7.5 million acre feet (maf) of water per annum. It also provided that the Upper Basin will not cause the flow of the river at Lee Ferry to be depleted below an aggregate of 7.5 maf for any period of ten consecutive years. The Mexican Treaty of 1944 allotted to Mexico a guaranteed annual quantity of 1.5 maf. **These amounts, when combined, exceed the river's long-term average annual flow**.
      

4. Education Outreach Partnerships CIG Stakeholders Planning Partnerships
Seattle Public Utilities
Portland Water Bureau
Northwest Power and Conservation Council
Idaho Dept. of Water Resources
Demonstrate a long-term commitment and responsiveness (takes several years to develop interest and/or trust)
Key stakeholders
Federal: Bonneville Power Administration, Natural Resource Conservation Service, Army Corps of Engineers, Forest Service
Tribal: Columbia River Intertribal Fisheries Commission, Northwest Intertribal Fish Comm.
State: WA Depts of Ecology, Natural Resources, Fish & Wildlife; OR Dept of Lands (Coastal Mgmt), ID Dept of Water Resources
Local: Seattle Public Utilities (Water), Seattle City Light, Portland Water Bureau

5. CIG Annual Water Workshops

6. Critical Period Planning Methods for Water Studies
Observed Streamflows
Planning Models
System Drivers

7. Climate Change Scenarios
Incorporating Climate Change in Critical Period Planning
Long term planning for climate change may include a stronger emphasis on drought contingency planning, testing of preferred planning alternatives for robustness under various climate change scenarios, and increased flexibility and adaptation to climate and streamflow uncertainty.
Observed Streamflows
Planning Models
Altered Streamflows
Climate Change Scenarios
System Drivers

8. Changes in Mean Temperature and Precipitation or Bias Corrected Output from GCMs
ColSim
Reservoir
Model
VIC
Hydrology Model

9. The main impact: less snow
VIC Simulations of April 1 Average Snow Water Equivalent
for Composite Scenarios (average of four GCM scenarios)
Current Climate
2020s
2040s
Snow Water Equivalent (mm)

10. Naturalized Flow for Historic and Global Warming Scenarios
Compared to Effects of Regulation at 1990 Level Development
Historic Naturalized Flow
Estimated Range of
Naturalized Flow
With 2040’s Warming
Regulated Flow

11. Effects to the Cedar River (Seattle Water Supply)
for “Middle-of-the-Road” Scenarios

12. Web-Based Data Archive

13. Climate Change May Exacerbate Other Impacts
climate change and growth
growth
climate change
Exceedance Probability of Reduced Storage Value from Current Climate and 2000 Demands

14. Climate change adaptation may involve complex tradeoffs between competing system objectives
Source: Payne, J.T., A.W. Wood, A.F. Hamlet, R.N. Palmer and D.P. Lettenmaier, 2004, Mitigating the effects of climate change on the water resources of the Columbia River basin, Climatic Change (in press).

15. There may be thresholds associated with impacts
Water supply timing changes estimated to occur by 2020 are handled by the storage and allocation system with little shortage change. However, the modeled reductions in water amount by 2040 would produce much more significant irrigation water shortages. These results could be made worse by changes in water demand.

16. Sources of Uncertainty

17. Problems with potentially biased spatial patterns in free running GCMs
Do free running GCMs accurately reproduce the position of dominant storm tracks for particular regions?
How far can GCM output be downscaled if the position of the storm track is unrealistic or biased?
Snake gets wetter
Snake gets drier
Current
Current
Future
Future

18. Effects of the PDO and ENSO on Columbia River
Summer Streamflows
PDO
Cool
Cool
Warm
Warm
high
high
low
low
Ocean Productivity

19. Trends in Annual Streamflow at The Dalles from 1858-1998 are strongly downward.

20. The Dust Bowl was probably not the worst drought sequence
in the past 250 years
red = observed, blue = reconstructed
Source: Gedalof, Z., D.L. Peterson and Nathan J. Mantua. (in review). Columbia
River Flow and Drought Since Submitted to Journal of the American
Water Resources Association.

21. Role of Monitoring in Scenario Validation

22. 20th century decline in NH snow cover
Surface measurements
Satellite meas.
Winter months show increases in snow cover
Open diamonds are from surface measurements, closed diamonds from satellite meas.
Brown, R.D., 2000: Northern Hemisphere snow cover variability and change, Journal of Climate, vol 13.
R.D. Brown, J. Climate, 2000

23. Trends in April 1 snow water equivalent, 1950-2000
Source: Mote et al. (2004)

24. Snowmelt runoff timing trends, 1948-2000
Graphic provided by Dan Cayan, Scripps Institute of Oceanography and the USGS. To appear in Climatic Change, 2003

25. Some Broad-Based Management Alternatives
Supply Side
Increase conventional storage
Build new storage projects
Enlarge existing storage projects
Off-stream surface water storage projects
Ground water storage and recharge
Advanced waste water treatment systems (Yelm, WA)
Reverse osmosis in coastal areas
Improve forecasting systems and management
Demand Side
Conservation and plumbing codes
Pricing of water to reflect scarcity and demand
Market based transfers and water banks

26. Approaches and Criteria for Identifying Preferred Management Alternatives and Robust Planning Strategies
1) Identify the components of the planning process that are sensitive or insensitive to climate uncertainties
2) Identify planning alternatives that are acceptable and robust to different climate scenarios, even if they are perhaps not optimal under all climate scenarios
3) If no one plan is best under all climate scenarios, then identifying which plan is best for each scenario may be helpful in assessing the ability to respond to evolving conditions.
4) Identify alternatives that are more flexible than others in the sense that they can be substantially altered as uncertain conditions evolve. Such plans may be preferable if the water system is very sensitive to altered climate (and particularly uncertain projections of precipitation variability).
5) Identify plans that have "irreversible" components (e.g. because of investment in infrastructure or other capital expenditures). Such plans may in some cases increase future risks and reduce response capability.
Identify "no regrets" strategies that create desirable outcomes regardless of uncertainties. (e.g. improve communication drought planning)
Identify management alternatives or planning strategies that are “self tending” and evolve dynamically without recursive policy intervention. (e.g. water markets or water pricing mechanisms)

27. Selected References and URL’s
Climate Impacts Group Website
White Papers, Agenda, Presentations for CIG 2001 Climate Change Workshop
Climate Change Streamflow Scenarios for Water Planning Studies
Refs on Climate Variability and Climate Change