Denver Water's climate adaptation planning perspective focuses on addressing climate change uncertainties. Projections show temperature increases of 2-5°F and precipitation changes from -20% to 30% by 2040-2070 in north central Colorado, posing challenges to water supplies and demands. Denver Water uses simple assessments of how much additional precipitation would be needed to offset warming impacts, showing potential yield decreases of 22% and demand increases of 7% under 5°F warming. Scenario planning helps identify decision points and flexible strategies to address uncertainties like population growth, endangered species, drought, and compact calls on the Colorado River. Adaptation requires understanding climate science capabilities and limitations, assessing vulnerabilities, incorporating uncertainty into planning, and implementing strategies to increase reliability,

1. CLIMATE ADAPTATION
PLANNING:
A UTILITY PERSPECTIVE
January 21, 2015 Watershed Summit
Laurna Kaatz - Climate Scientist, Denver Water

2. Grand Junction
Aspen
Arkansas River
South Platte River.
Yampa River
Gunnison River
Colorado River
Continental Divide
South Platte
Watershed
Colorado River
Watersheds
Continental Divide
Denver
Transbasin
Diversions
2
2

3. -20 %
-10 %
%
10 %
20 %
30 %
1 ° 2 ° 3 ° 4 ° 5 ° 6 ° 7 ° 8 ° 9 ° 10 °
PrecipitationChange(%)
Temperature Change (Fahrenheit)
2040
2070
0
3
Projected Changes for
North Central Colorado

4. Climate Adaptation Challenges
• What information should
we use?
• How do we use it?
– Conversion tools
– Simple vs sophisticated
– Probabilities or scenarios
– What do we plan for
– Trade-offs
• New science
• Messaging

6. Denver Water’s Simple Assessments
6
2° F 5° F
Colorado South
Platte
Colorado South
Platte
Additional
precipitation
needed to offset
warming
5% 5% 8% 12%
5° F
% Change
Yield -22%
Demand 7%

7. Water Planning Challenges
7
Colorado River
Compact Call
Population Growth
Endangered Species
Climate Change
Drought
Water Quality

8. Scenario Planning
8
2050
B
Decision
Points
2010
C
Near-term strategy A
D
E
The Cone of Uncertainty

9. • Traditional future - The future is extrapolated from past
trends.
• Water quality rules - Contaminant removal and other
drinking water requirements are extremely stringent.
• Hot water - A warmer climate accompanied by more
frequent and more severe droughts.
• Economic woes - An ongoing energy crisis and deep
economic downturn.
• Green revolution - Environmental values and sustainable
living become dominant social norms.

10. Planning Futures
WaterDemand
Supply Gap in 2050
Gap Existing Supply

11. Conclusions
• Increase system
reliability, diversity
and flexibility
• Plan for multiple
futures
• Identify and
preserve options
11

12. Four Adaptation Steps
• Understand climate science and model
projections capabilities and limitations
• Assess water system vulnerabilities to
potential change
• Plan to incorporate climate change
uncertainty into water utility planning
• Implement adaptation strategies

13. Resources at wucaonline.org
Understanding Planning

14. “All I’m saying is now is the time to develop a
plan to deflect an asteroid.”

15. Extra Slides

16. Water Utility Climate Alliance
Seattle
Public Utilities (Chair)
San Francisco
Public Utilities
Commission
Metropolitan
Water District
of So. California
San Diego
County Water Authority
Southern Nevada
Water Authority
Denver
Water
Portland
Water Bureau
Tampa Bay
Water (Vice Chair)
Central Arizona
Project
The Water Utility Climate Alliances provides leadership in assessing and adapting to the potential effects of climate
change through collaborative action. We seek to enhance the usefulness of climate science for the adaptation
community and improve water management decision-making in the face of climate uncertainty.
New York
Department of
Environmental
Protection