DROUGHT CONTINGENCY PLANNING AND COLORADO RIVER RISK STUDY AN OVERVIEW AND STATUS REPORT MARCH 2018 OUTLINE Drought Contingency Planning (DCP) 1. Background 2. Planning Process 2013-Present Colorado River Risk Study (West Slope BRTs) 1. Background 2. Phase I 3. Phase II What’s Next? 53' 53? r: c- c: Snow?atar Equivalent {inohash c: 0.0 Oct??l Upper Colorado River Basin HighlLow Snowpaok Summary Based on Provisional SNDTEL data as of Mar 12, 2013 Current as Current as Current as Current as Normal as Dr?Aug: Pot of Pea Dot of Peak Man-ch al: T956 15% 63% 85% ha Dix-11'4" Pot of Last Year: 50% I vi I'Iull Normal Pa Iul 3k Data: An LU r10 5.Jun {1'1 Feb 01 Mar 01 Apr [1'1 May 01 ?wu:-r ?wur.1 What if drought periods of past 25 years repeated? - Current conditions at Powell: about 60% full Jan 1 2018 - Three recent droughts superimposed on current conditions (drawdowns based on historical record) - No contingency planning actions in place; no water banking in place Elevation 3525: Threshold for Lower Operating Tier; Reclamation is concerned about Hydropower efficiency and hydraulics/cavitation below this level Elevation 3490: Ability to make releases per 2007 Interim Guidelines (and hence Compact Compliance) is jeopardized BACKGROUND AND CATALYST FOR DCP AND RISK STUDY • July 2013: Secretary Jewell asks basin states “if 2000 – 2013” drought conditions continue, are you prepared: ANSWER – NO! • Fall 2013: SNWA and Reclamation analysis for Lower Basin States illustrate possibility of critical storage levels in Mead and Powell and potential for a compact “hole”. • Upper Basin and Lower Basin begin coordinated, but independent development of contingency plans. • Dec 2014 Joint West Slope BRT Meeting, Request was made for additional studies. • Colorado’s Water Plan: Take actions that will minimize risk of compact curtailment actions (pt. 4 of Seven Point Framework) WHAT ARE “CRITICAL ELEVATIONS” AT POWELL? • If Lake Powell drops below el. 3525’ on January 1, 2007 Guideline operations are in the Lower Balancing Tier – This can lead to an increase in releases • Minimum elevation for turbine intakes is el. 3490’, but Reclamation will be concerned about air entrainment and generation efficiency at ~el. 3525’ 7.5 MAF December 2007: Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead UPPER BASIN DROUGHT CONTINGENCY PLANNING Upper Basin Objective: Identify actions that can reduce the risk of either losing power production at Powell or lose ability to meet our compact obligations Three Component Solution: 1. Coordinated Drought Operations of initial CRSP Reservoirs (Powell, Flaming Gorge, Aspinall , Navajo) • First line of defense against critical Powell elevations 2. Explore Voluntary and Compensated Demand Management • System Conservation Pilot Project • Water Bank Work Group 3. Cloud Seeding UPPER BASIN DCP DROUGHT OPERATIONS DETAILS • Initial Storage Units of CRSP (Powell, Flaming Gorge, Aspinall, Navajo) • If August 24-month forecast indicates January 1 Powell elevation will be below the trigger elevation (3525’), implement Drought Operations • 1st option: modify timing of Powell Releases • 2nd option: Utilize Flaming Gorge, Aspinall, Navajo • Move water from those CRSP units to Powell • Implement at all three upper CRSP reservoirs simultaneously • Does not mean all three can necessarily contribute. • Constraints of Contracted water, Records of Decision, Hydrology • Operations covered by current Records of Decision (NO reconsultation) • Formal agreement between Reclamation and UB States is in the works. PROPOSED LOWER BASIN DCP (AND MEXICO) Lower Basin reductions based on Mead elevations, and are in addition to 2007 Interim Guidelines’ Shortage Criteria Lower Basin conservation begins at elevation 1090’ (200 kaf), which is higher than the current IG shortage criteria threshold Could result in as much as 1.325 maf of Lower Basin conservation if Mead is forecast to drop below 1020’ Agreement valid through 2026 (if approved) Minute 323 – U.S. / Mexico Treaty MX participation in shortage sharing pro-rata with 07 Guidelines MX will participate in DCP if and when LB States approve and implement x/ JOWER BASIN DCP CONSERVATION SCHEDU LE Lake Mexico Mead AZ Total CA Total USBR Minute Total 2007 Plan 200? Plan Total 200? Plan Elevatmn 319,, 1,090- 1 ?3'5 0 192,000 192,000 0 3,000 3,000 0 0 0 100,000 0 300,000 1,025- 1 050 320,000 192,000 512,000 13,000 3,000 21,000 0 0 50,000 633,000 1,050- 3353: 1 045 400,000 102,000 592,000 12,000 0,000 25,000 0,000 20,000 202,000 ling; 400,000 240,000 040,000 12,000 10,000 X000 20,000 1,002,000 1035 400,000 240,000 040,000 - 250000 101,20:- 0 20,000 1,002,000 1,035- 2 300000 100,000 20,000 1,132,000 1,030 1,050- 1025 350,000 350000 100,000 20,000 1,132,000 01,025 050,000 050000 100,000 DCP OUTCOMES Powell and Mead are operationally coupled through the ‘07 Guidelines Neither Basin can completely mitigate its own risk: The best solutions require participation by both Upper and Lower Basins. 3525 3490 Preliminary Results – Not for Distribution DCP OUTCOMES Powell and Mead are operationally coupled through the ‘07 Guidelines Neither Basin can completely mitigate its own risk: The best solutions require participation by both Upper and Lower Basins. 3525 3490 Preliminary Results – Not for Distribution COLORADO RIVER RISK STUDY • Originated from joint West Slope BRT discussions and reflection on DCP process • Funding via Colorado River District, Southwestern, West Slope BRTs (CWCB) • Colorado’s Water Plan: Take actions that will minimize risk of compact curtailment actions (pt. 4 of Seven Point Framework) • Phase I completed Fall 2016 • Phase II ongoing (completion Spring 2018) WEST SLOPE BRT STUDY – PHASE I • Questions to answer in Phase I: • What are magnitude and duration of Powell shortages below elevation 3525’? • How much of the above shortages can be met by contributions from Drought Operations of CRSP reservoirs? (A: up to about 2 MAF) • How much consumptive use reduction (“demand management”) would be needed by Upper Basin states - AFTER use of stored CRSP water - in order to maintain Powell pool elevations? • What are possible implications to Colorado River water users? What is range of volumes that Colorado might need to conserve? (Colorado’s apportionment under the 1948 Upper Basin Compact is 51.75%, but we’re currently using about 56-58% of UB total) • Use Reclamation’s “Big River” CRSS Model to address these “What If” questions… HYDROLOGIC i Jan 1 Powell PE 3525' +25yr ISM (1988-2012} Demand A -?Perl'ocl of Record {1950?2012) Demand A +C imate Change Demand A Modeled Frequency of Occurrence 2096 1096 0% - 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 202? 2028 2029 2030 2031 2032 2033 2034 2035 2036 YEAR DEMAND SE Jan 1 Powell PE 3525? 25yr ISM Demand Schedule A Demand Schedule D1 Demand Schedule Modeled Frequency of Occurrence bx 1/ 1096 I 0% 2016 2013'' 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027' 2028 2029' 2030 2031 2032 2033 2034 2035 2036 YEAR CRSP DROUGHT OPERATIONS AND LOWER BASIN CONSERVATION REDUCES THE RISK, BUT DOES NOT ELIMINATE IT Preliminary Results – Not for Distribution r7 1_ TO ?1 Annual 1ll'olumes Needed to Maintain Powell 3525 on Dec 31 2016?2036 Simulation Period 20 13 Demand Schedule A 15 Demand Schedule 9050?100 100? 500 500? 1,000? 1,500? 2,000? 2,500? 1,000 1,500 2,000 2,500 3,000 . WEST SLOPE BRT STUDY – PHASE II Phase II Scope of Work: • Task 1: CRSS “Infilling” - additional model runs and completion of CRSS modeling report • Water Banking • Paleo Hydrology • Sensitivity Analysis (Storage Conditions, Demands) • Task 2: StateMod investigations • Investigate use of StateMod for addressing water use, storage, and demand management questions • Look at coupling of StateMod and CRSS to leverage benefits of each tool. PHASE II STATEMOD WORK • “Evaluate the utility of using StateMod in addressing questions related to voluntary demand management. Understand capabilities and limitations” 1. Uniform reduction in demands / consumptive use across all users a. What is state line “yield” with 5%, 10%, 15% reductions? b. How does this yield change with hydrology and across different basins? 2. What is yield with and without shepherding? a. “Non-Shepherded” Scenario: Junior rights who may have been shorted initially may receive additional water by virtue of upstream reductions, even though their own demands are also reduced b. Shepherded Scenario: reductions arrive undepleted at state line (loss factor may be applied if desired) PHASE II STATEMOD WORK • “Evaluate the utility of using StateMod in addressing questions related to voluntary demand management. Understand capabilities and limitations” 3. How can we represent water banking mechanisms in the model? a. Size and location of reservoir(s) b. Ability to operated water bank using triggers? 4. Comparison to and linking with CRSS a. Data compatibility (hydrology, demands, etc.) b. “linked” simulations: ex: Powell elevations drive demand management, and increased flows accrue to Powell. ALL YEARS (1988-2012) • Reduce CU (demand management) on all direct flow rights • Efficiency is percent of conserved water reaching state line (non-shepherded). DRY YEARS • Reduce CU (demand management) on all direct flow rights • Efficiency is percent of saved water reaching state line (non-shepherded). TAKE-AWAYS • Distribution of yield: • Colorado Main stem ~ 40%-50% • Gunnison and SJ/Dolores ~ 10%-25% each • Yampa / White ~ 10%-20% • Shepherding is important • Especially in dry years • And in basins with relatively higher demands as a % of flow (Colorado main stem, Gunnison*, San Juan/Dolores) • *Gunnison impacted by Aspinall (Blue Mesa) storage right • Note: Shepherding work by Anne Castle, Larry MacDonnell and others • StateMod is the right tool to address demand management questions WATER BANKING CONCEPT • Conserved CU is stored in the Bank • Banked water does not become system water unless released from the Bank. (i.e., not subject to equalization) • Water Bank releases water only to support Lake Powell elevation, after Drought Operations of upstream CRSP Reservoirs. • Challenge: Find sufficient and persistent storage space for banking Flaming Gorge 1.0 MAF Water Bank Reservoir Aspina ll Lake Powell Nava jo CRSS / STATEMOD COUPLING • Colorado River Simulation System (CRSS) • Good: representation of “Big River” operations; Powell/Mead; Drought Operations of CRSP facilities • Bad: does not simulate water right administration in Colorado • StateMod • Good: Simulates priority administration of water, additional yield from demand management activities; the only tool available for detailed analysis of demand management and shepherding issues within Colorado. Can couple with other CDSS tools for estimating CU savings under conservation programs (e.g., StateCU, LeaseFallow Tool) • Bad: model is Colorado-specific; No “knowledge” of Powell/Mead or other “big river” conditions; limited ability to “control” banked water • Concept: Utilize StateMod for development of demand management yields, use CRSS to manage the resulting bank and usage of water at Powell nnEm: nun; Enamng HE 3415 STE _m=.Hm _m=.Hu _m=.Hm _m=.Hm - . - E?m_u - . II. E. .. mm _m=.mm . .. E?mm 1 H. ?Wih Bank'ng ?anking E?mm- - - E?mm E?mm_ acre-Ft 1?0 1?20 20 1?0 1?20 25 1?0 1?20 30 1?0 1?20 35 1?0 1?2040 EDSS.WaterH-ank Eleva?un 3.700.00 3550.00 3500.00 3550.00 3500.00 STATEMOD/CRSS LINKAGE SUMMARY • Need to simulate “Big River” policy and operations together with sub-basin specific water rights administration questions. • StateMod and CRSS each have strengths and weaknesses in this application, but together they can be an effective tool. • There are some remaining challenges. For example: • Ensure “synchronization” of data across models, especially hydrology and demands • How to handle dynamic demand management and yields with specific water users, partial-season fallowing, return flow impact, other conservation activities THE BIG PICTURE • Hydrology, Current Consumptive Use, and Future Demands matter. We can’t control hydrology, but the higher the consumptive use in the UB the higher the risk to existing users. • The most successful DCP requires joint participation by both Upper and Lower Basins. Additional measures in the UB may be necessary to eliminate risk. • Contingency Planning is essential; CRSP reservoir drought operations reduces the risk, but in more severe droughts, demand management (ideally the use of previously conserved water from a bank) could be necessary. • Some of the shortage volumes we are seeing in the model are very large and may not be feasible, need to consider the “trade-offs” and alternative strategies • Demand Management combined with a Water Bank: • Could limit the Annual impact to CU by spreading Conservation over many years • Would provide greater control over conserved water (a “must have” condition) WHAT’S NEXT? • DRAFT Phase I & II Report to Technical Advisory Committee (March) • Individual BRT Webinars (March) • Joint West Slope BRT Meeting (Tentative April 25) • CWCB Board Presentation (March 21) • Phase III • Basin-specific questions as requested by BRTs. • Funding? • Participants? WATER BANK OUTCOMES Effectiveness of water bank? • Needs to be an add-on to Drought Contingency Plan • Does not always keep Powell above 3525, but.. • Can increase minimum Powell elevation by ~15-20 ft. (e.g. 3481.2 to 3497.6 in Scenario 6 above) • UB States need to control “if and when” of banked water releases Preliminary results, not for distribution Available Space for Banking in Colorado, Baseline StateMod Scenario, 1933-2012 1,000,000 900,000 300,000 ?00,000 600,000 500,000 ?100,000 300,000 200,000 100,000 acre-Ft 1?20 20 1?0 1?29 25 1?0 1?29 1?0 1?29 35 1?20-10 CDSS-Water?-ank Paw-ell- Pun-I Elevatinn 5 1-0 1-3} 1-01-2025 1-01-2021} SanJuan Demand Management Fbw.Ou?10w 1-0 1-20 35 1-0 1-2040