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climate -3 Planners in S. California, for Instance, Face a Range of Possible Future Climate Conditions Summer-time temperature change ( ) +.1C +2.1C 0 Likely range Results based on statistical summary of 21 of the world’s best Global Climate Models No change Hotter Wetter Winter-time precipitation change ( ) +8% -19% 0 Likely range Much drier Water managers also face many similar, if not more, disruptive uncertainties
Citation preview
Water Management and Climate Change in the US-
Mexico Border Region
Robert LempertSenior Scientist
RAND
September 27, 2008
climate -2
Climate Change Poses Significant Challenge for Resource Planning the US-Mexico Border Region
• “Stationarity is dead” – Many organizations already include climate (often implicitly) in
their decisions – Amidst all the uncertainty one thing we do know for sure --
tomorrow’s climate will not be like the past’s
• Changes in West are likely to include:– Increased temperatures– Changes in precipitation patterns– More intense storms– Declining snow pack and summertime river flows
• Without proper planning:– Supply expectations may not be met– Demand may grow faster than can be accommodated– Infrastructure may fail
climate -3
Planners in S. California, for Instance, Face aRange of Possible Future Climate Conditions
Summer-time temperature change(2000- 2030)
+.1C +2.1C0
Likely range
Results based on statistical summary of 21 of the world’s best Global Climate Models
No change Hotter
Wetter
Winter-time precipitation change (2000 - 2030)
+8%-19% 0
Likely rangeMuch drier
Water managers also face many similar, if not more, disruptive uncertainties
climate -4
Our Work With California Water Agencies Suggests Lessons for US-Mexico Border Region
• Resource managers can no longer assume future climate will be like the past
• Despite deep uncertainty, sufficient information exists to support prudent action today
• Effective response options are available
• Legislatures may have to help ensure:– Access to appropriate data and information
– Funding for demonstration projects and new infrastructure
– Appropriate incentives and perhaps some regulatory changes
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Conducted Vulnerability and Options Analysis for Inland Empire Utilities Agency (IEUA)
– IEUA currently serves 800,000 people
• May add 300,000 by 2025– Water presents a significant
challenge
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– Current water sources include:
• Groundwater 56%• Imports 32%• Recycled 1%• Surface 8%• Desalter 2%
Conducted Vulnerability and Options Analysis for Inland Empire Utilities Agency (IEUA)
– IEUA currently serves 800,000 people
• May add 300,000 by 2025– Water presents a significant
challenge
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– Current water sources include:
• Groundwater 56%• Imports 32%• Recycled 1%• Surface 8%• Desalter 2%
Focus of IEUA’s 20 year plan
Conducted Vulnerability and Options Analysis for Inland Empire Utilities Agency (IEUA)
– IEUA currently serves 800,000 people
• May add 300,000 by 2025– Water presents a significant
challenge
climate -8
Our Research Focused on Two Key Questions
• Are IEUA’s plans vulnerable to assumptions about uncertain future conditions, including climate change?
• Which actions should IEUA do now and which can they defer to later to address the threat of climate change?
climate -9
We Identified Three Types of Assumptions That Could Impact the Performance of IEUA Plans
• Imported supplies• Water use efficiency
Costs of Future Supplies and Management Activities
• Development of aggressive waste-water recycling program
• Implementation of groundwater replenishment
Performance of Management Strategies
• Future temperatures• Future precipitation• Changes in groundwater processes
Natural Processes
climate -10
We Identified Three Types of Assumptions That Could Impact the Performance of IEUA Plans
• Imported supplies• Water use efficiency
Costs of Future Supplies and Management Activities
• Development of aggressive waste-water recycling program
• Implementation of groundwater replenishment
Performance of Management Strategies
• Future temperatures• Future precipitation• Changes in groundwater processes
Natural Processes
climate -11
We Identified Three Types of Assumptions That Could Impact the Performance of IEUA Plans
• Imported supplies• Water use efficiency
Costs of Future Supplies and Management Activities
• Development of aggressive waste-water recycling program
• Implementation of groundwater replenishment
Performance of Management Strategies
• Future temperatures• Future precipitation• Changes in groundwater processes
Natural Processes
climate -12
IEUA Faces a Wide Range of Possible Future Climate Conditions
Summer-time temperature change(2000- 2030)
+.1C +2.1C0
Likely range
No change Hotter
Wetter
Winter-time precipitation change (2000 - 2030)
+8%-19% 0
Likely rangeMuch drier
climate -13
Model Performance of plans
IEUA Plans
System data & climate forecasts
Our Simulation Model Assessed Performance of IEUA Plans in Different Future States of World
Temp: +1.6Temp: +1.6ooC Precip: -10%C Precip: -10%
Scenario BPlan suffers shortages in adverse future climate
005050
100100150150200200250250300300350350400400
20052005 20102010 20152015 20202020 20252025 20302030YearYear
Ann
ual s
uppl
y (ta
f)A
nnua
l sup
ply
(taf)
RecycledRecycled
GroundwaterGroundwater
Local SuppliesLocal Supplies
ImportsImports
Dry-year yieldDry-year yieldSurplusSurplus
ShortageShortage
Temp: +0.7Temp: +0.7ooC Precip: +3%C Precip: +3%
Scenario APlan generates surpluses in benign future climate
005050
100100150150200200250250300300350350400400
20052005 20102010 20152015 20202020 20252025 20302030YearYear
Ann
ual s
uppl
y (ta
f)A
nnua
l sup
ply
(taf)
RecycledRecycled
GroundwaterGroundwater
ImportsImportsSurplusSurplus
Local SuppliesLocal Supplies
climate -14
IEUA’s Ability to Implement Its Plan and The Agency’s Future Costs are Also Uncertain
• Estimates of agency’s likelihood of achieving its recycling and ground water goals
• Future costs of alternative sources of supply
0 250 500 750 1,000 1,250 1,500
Saved through efficiency
Recycled
Storm-water replenishment
Groundwater
Recycled replenishment
Imported (Tier 1)
Imported replenishment
Imported (Tier 2)
Desalted groundwater
Shortages
Cost component
Levelized costs for 2005 and 2015 ($ per af)
1,860
climate -15
Simulation Suggests that Climate Change Exacerbates Other Risks to IEUA’s Plan
Factors consideredPerformance towards recycling goalPerformance towards replenishment goalFuture climateAmount of new conservationAmount of groundwater infiltrationEffect of climate on imports
Ran simulation 1,000 times for many different
combinations of uncertain factors
In 656 cases IEUA’s plan has low cost
In 344 cases IEUA’s plan has high cost
What factors explain these high cost cases?
Key Vulnerabilities to IEUA PlanMiss recycling goal
Adverse future climate
Any reduction in groundwater infiltration
climate -16
Our Research Focused on Two Key Questions
• Are IEUA’s plans vulnerable to assumptions about uncertain future conditions, including climate change?
• Which actions should IEUA do now and which can they defer to later to address the threat of climate change?
climate -17
Response Options May Help IEUA Address These Vulnerabilities
• Efficiency reduces demand but imposes costs on customers and requires customer participation
• Improved groundwater management increases resilience to shortages but requires significant cooperation and faces unknown costs
• Recycled water use is a drought-proof supply but requires significant public support
Each Option Has Benefits and Costs
climate -18
Should IEUA Act Now or Later to Reduce Potential Climate Vulnerabilities?
Act now to Act now to augment augment
2005 Plan?2005 Plan?
NO
Monitor, and take Monitor, and take additional action if additional action if supplies drop too supplies drop too
lowlow
In 2015, 2020, 2025, ….
YESImplement Implement additional additional efficiency, efficiency,
recycling, and recycling, and replenishmentreplenishment
In 2015, 2020, 2025, ….
Monitor, and take Monitor, and take additional action if additional action if supplies drop too supplies drop too
lowlow
climate -19
We Evaluated Nine Strategies Under200 Scenarios Reflecting Key Uncertainties
Number of Scenarios (PV Costs > $3.75 billion)0 40 8060 100 12020
Current Plan Forever
UWMP + DYY and recycling
UWMP + replenishment
UWMP with updates
UWMP + replenishment with updates
UWMP + efficiency
UWMP + efficiency with updates
UWMP + DYY and recycling with updates
UWMP + all enhancementsStatic optionsUpdate options
climate -20
Just Allowing the Current UWMP to UpdateReduces Vulnerability Substantially
0 40 8060 100 12020
Static optionsUpdate options
From 120Down to 30
Number of Scenarios (PV Costs > $3.75 billion)
Current Plan Forever
UWMP + DYY and recycling
UWMP + replenishment
UWMP with updates
UWMP + replenishment with updates
UWMP + efficiency
UWMP + efficiency with updates
UWMP + DYY and recycling with updates
UWMP + all enhancements
Still vulnerable to:• Precipitation declines• Declines in imports • Costs of imports
climate -21
Implementing Efficiency and Other Options NowReduces Future Vulnerabilities Even More
0 20 403010
Static optionsUpdate options
Number of Scenarios(PV Costs > $3.75 billion)
UWMP with updates
UWMP + replenishment with updates
UWMP + efficiency
UWMP + efficiency with updates
UWMP + DYY and recycling with updates
UWMP + all enhancements
Implementation becomes
more challenging
climate -22
Implementing Efficiency and Other Options NowReduces Future Vulnerabilities Even More
0 20 403010
Static optionsUpdate options
Number of Scenarios(PV Costs > $3.75 billion)
UWMP with updates
UWMP + replenishment with updates
UWMP + efficiency
UWMP + efficiency with updates
UWMP + DYY and recycling with updates
UWMP + all enhancements
IEUA should make more near-term efficiency investments; monitor performance and adapt as needed down the road
Implementation becomes
more challenging
climate -23
US-Mexico Border Region Can and Must Begin Adapting to Climate Change
• Resource managers can no longer assume future climate will be like the past
– Impacts of climate change may create significant vulnerabilities in agencies’ operations and plans
• Despite deep uncertainty, sufficient information exists to support prudent action
– New planning methods may prove necessary
– Key is identifying near-term actions that are robust over a wide range of plausible futures
• Effective response options are available– Inland Empire Utilities Agency should increase investment in near-
term conservation, monitor carefully, and prepare to take further actions
– Other agencies may require additional near-term responses
climate -24
climate -25
Analysis Suggests Three Such Driving Forces
• Conducted statistical, cluster-finding analysis over all the model runs to identify the factors most strongly associated with shortages in 20 Year Plan
Meet recycling goal
Meet replenishment goal
Future climate
New conservation
Reduced groundwater infiltration
Climate on imports
Miss ExceedMeet
Miss ExceedMeet
Drier Wetter
-5% +20%
-20% 0%
Weak Strong
Explains 127 (of 180) low surplus cases
climate -26
Simulation Model Evaluated IEUA’s Current Plan Under Many Different Scenarios
IEUA WaterManagement
Options
Uncertainties
SimulationModel
OptionPerformance
climate -27
Scatter Plots Summarize Supply and Shortage Costs for Each Scenario for Current Plan
0 1.0 2.0 3.0 4.0PV shortage cost ($ billions)
2.5
3.0
3.5
4.0
PV supply cost
($ billions)
Current Plan Forever
climate -28
0 1.0 2.0 3.0 4.0PV shortage cost ($ billions)
2.5
3.0
3.5
4.0
PV supply cost
($ billions) Scenario A
• Modest warming and minimal precipitation decrease
• $3.3 billion in supply cost
• $0 in shortage cost
Current Plan Forever
Scenario B
• Significant warming and precipitation decrease
• $3.4 billion in supply cost
• $1.9 billion in shortage cost
Scatter Plots Summarize Supply and Shortage Costs for Each Scenario for Current Plan
climate -29
0 1.0 2.0 3.0 4.0PV shortage cost ($ billions)
2.5
3.0
3.5
4.0
PV supply cost
($ billions)
Current Plan Forever
(200 Scenarios)
Scatter Plots Summarize Supply and Shortage Costs for Each Scenario for Current Plan
climate -30
The Current Plan Performs PoorlyUnder Many Possible Future Conditions
0 1.0 2.0 3.0 4.0PV shortage cost ($ billions)
2.5
3.0
3.5
4.0
PV supply cost
($ billions)
Current Plan Forever
$3.75 billion cost threshold
(120 of 200 Scenarios)
climate -31
Statistical Analyses Suggested Three MajorVulnerabilities to the IEUA Plan
0 1.0 2.0 3.0 4.0PV shortage cost ($ billions)
2.5
3.0
3.5
4.0
PV supply cost
($ billions)
Current Plan Forever
$3.75 billion cost threshold
(120 of 200 Scenarios)
1. Strong declines in precipitation
2. Reductions in imported supply
3. Changes in groundwater replenishment