Robust Risk Analysis, Bottom up Climate Preparedness, and Multi objective Optimization: The Future of Water Utility Planning

Transcription

1 Robust Risk Analysis, Bottom up Climate Preparedness, and Multi objective Optimization: The Future of Water Utility Planning Leon Basdekas Kevin Lusk Enrique Triana Chip Paulson Brett Gracely March 31, 2015 Electricity Natural Gas Water Wastewater

2 Outline IWRP Overview Public process Key Factors Performance Metrics Water Supply Planning Approach Hydrologic/climate stress testing System Risks Multi-Objective Optimization Next steps

3 IWRP Overview

4 Colorado Springs Water System Complex system 70% comes from over Continental Divide (Colorado River) 4 collection systems carry water through 4 tunnels Delivered by 3 pipelines, soon to be miles of pipes Water travels up to 100 miles to the city 25 reservoirs used to store water

5 IWRP Purpose xx When the well is dry, we know the worth of water. Ben Franklin Road map for the future Long-range plan ~ 50+ years Examines water supply water demand water quality Infrastructure Energy regulatory, legal issues, and public opinion Electricity Natural Gas Water Wastewater 5

6 IWRP Goals xx Ensure our customers have a continued sustainable, long-term water supply Ensure resilient and reliable water supply Deliver water cost effectively Deliver water in an environmentally responsible manner Develop a plan that is acceptable and explainable to our customers Electricity Natural Gas Water Wastewater 6

7 Public Process Summary Web Page Focus groups Presentations/meeting with stakeholders Approximately 32 meetings held to date Met with 900+ people Water Planning Advisory Group 11 members 11 meetings held plus facility tours Open House Survey Electricity Natural Gas Water Wastewater

8 Key Factors Affecting Colorado Springs Water Resources Natural variability Competition for scarce land and water Federal land designations Permitting challenges Wild fires Effects to change in flow regimes (Increase diversions) Federal / State Nexus Environmental Challenges Climate Variability Water Supply Sustainability (Reliability, Cost, Social Values) Infrastructure Failures Aging Infrastructure Sabotage Electricity Natural Gas Water Wastewater Long-term variability Runoff timing Demand Variability Water Rights Challenges Population growth Demand hardening Exchange potential limitation Colorado River Basin Shortages West slope water rights obligations

9 Approach to Water Supply Planning

10 Key Metrics for System Performance (Illustration) Supply Storage YOD - Years of demand in storage Electricity Natural Gas Water Wastewater

11 Hydrologic Stress Test Overview Bottom up approach Temperature Adjustments (in Degree Celsius) of +1, +2, +3, +4, and No Change (+1C trend) Precipitation Adjustments of -15%, -10%, -5% and +5%, and No Change 25 T&P Scenarios per trial Different trials represent varying hydrologic conditions

12 Hydrologic Sensitivity Storage Reliability for Different Trials (1.0 YOD, 2016 Settings)

13 Hydrologic Sensitivity Storage Reliability for Different Trials (1.0 YOD, Build Out Settings)

14 Upper Colorado Basin Global Climate Model (GCM) Ranges CMIP3 CMIP5 Low Mid High Precipitation Change (%) Average results for 2050 period Temperature Change (F) Current climate

15 Risk Analysis Design In Phase I approximately 100 risks were identified Individual Risks (42 Total) Risk Scenario Storylines Combine risks that would be realized under foreseeable conditions (10 Total) Risk Combinations Learned from 2002 need to combine drought, infrastructure, and administrative risks Mix of short/long term and model all possible combinations Nearly 50,000 model runs total with 40 Hydrologic sequences Reliability Decrease Resiliency Decrease Electricity Natural Gas Water Wastewater

16 Options to Mitigate Risk Demand side management Conservation and education Land use policies New water supply Acquisitions Leasing New storage Where? How much? Conveyance projects When? Combinations? Tradeoffs? Electricity Natural Gas Water Wastewater

17 Searching for Risk Mitigation Measures The objective functions should be considered powerful screening criteria or metrics and not the final answer. Options to mitigate risk (projects, programs and policies) Subset of identified risk

18 MOEA Example Arkansas Basins Levers New Gravel Pit Storage Two Pipeline Conveyance options Agricultural Leases

19 MOEA Example Objective Function Maximize Storage Annual Reliability (1 YOD) Minimize Storage Vulnerability (1 YOD) Minimize Loss of Reusable Returns

20 Search Space Sample

21 Discovery of Inferior Spaces & Tradeoff Initial Performance

22 Next steps Evaluate risk tolerance levels and tradeoffs Develop a robustness measure to support decisions Evaluate options to mitigate risk Improve projected storage and demand metrics Cost Integrate WPAG and other public perspectives Initial Planning Obtain Feedback Electricity Natural Gas Water Wastewater Evaluate Options Recommendations

23 Summary Extensive public process, diverse stakeholders Analytically intensive Broad look at potential risks Broad and robust search for improved solutions Powerful framework to evaluate uncertainty and opportunities. Roadmap for future, signposts and alternate routes

24 Integrated Water Resource Plan Questions Leon Basdekas Colorado Springs Utilities Enrique Triana MWH Global, Inc. Electricity Natural Gas Water Wastewater

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