1. Initial Predictive Simulations with High Plains Aquifer System (HPAS) Groundwater Availability Model (GAM) Bill Hutchison, Ph.D., P.E., P.G. GMA 2 Meeting January 6, 2016

2. Final Model and Report Final Report Delivered to TWDB on 8/31/2015 Model Files Obtained in late October/early November 2015

3. INTERA Initial Simulation GMA 1 Part of contract deliverable Attempted to achieve 50/50 for all aquifers – Ogallala – Edwards-Trinity (High Plains) – Dockum

4. GMA 2 Initial Simulations Avoid “arbitrary” management goal Acknowledge historic management practices Focus on physics and economics of pumping groundwater Take advantage of a feature in HPAS related to dynamic reductions in pumping with decreased saturated thickness – No dry cells – No need to adjust input files for pumping (reduce pumping over time)

5. Fifteen Simulations Five alternative initial pumping rates – 50% of 2012 pumping – 75% of 2012 pumping – 100% of 2012 pumping – 125% of 2012 pumping – 150% of 2012 pumping Three saturated thickness thresholds – 20 ft – 30 ft (used in calibration) – 40 ft

6. Summary of Simulations

7. Ogallala Aquifer Results Pumping and Drawdown Results Pumping and Storage Remaining Results

8. Drawdown Results

9. Storage Remaining Results

10. Overall Observations Drawdowns are different in each county Storage remaining is different in each county Equal vs. Fair Focus on comparing pumping with drawdown and storage – Examples from Tech Memo One where 2070 storage is greater than 50% of 2012 One where 2070 storage is less than 50% of 2012 One where 2070 storage is about 50% of 2012

23. Takeaways HPAS dynamically simulates the expected reduction in pumping associated with decreased saturated thickness – No need to change input files to minimize dry cells Equal storage remaining approach (i.e. 50/50) is not recommended – On a county basis, some areas would need to increase pumping, some areas would need to decrease pumping – Long term, pumping would still tend toward the same amount

24. Next Steps - Ogallala Select one of the initial pumping scenarios – 100% to 125% of 2012 pumping Rerun with updates to ETHP and Dockum (next topics)

25. Edwards-Trinity (High Plains) Results Pumping and Drawdown Results

34. ETHP Pumping Recommendations Bailey – Historic Maximum (~1,000 AF/yr) Borden – Historic Maximum (~100 AF/yr) Cochran – Historic Maximum (~400 AF/yr) Dawson – 150% of 2012 (~3,500 AF/yr) Floyd – Historic Maximum (~2,000 AF/yr) Gaines – 150% of 2012 (~20,000 AF/yr) Garza – Historic Maximum (~300 AF/yr)

35. ETHP Pumping Recommendations Hale – 150% of 2012 (Scenario 10, declining to ~4,000 AF/yr by 2070) Hockley – 150% of 2012 (~130 AF/yr) Lamb – 200 AF/yr Lubbock – 150% of 2012 (~1,500 AF/yr) Lynn – 150% of 2012 (~1,800 AF/yr) Terry – Historic Maximum (~1,200 AF/yr) Yoakum – Historic Maximum (~2,000 AF/yr)

36. Dockum Results Pumping and Drawdown Results

46. Dockum Pumping Recommendations Andrews – 1,000 AF/yr Borden – 600 AF/yr Briscoe – 250 AF/yr Castro – 150% of 2012 (~500 AF/yr) Crosby – 150% of 2012 (~4,500 AF/yr) Deaf Smith – 5,000 AF/yr Floyd – 150% of 2012 (~4,000 AF/yr) Gaines – Not relevant for purposes of joint planning (zero pumping)

47. Dockum Pumping Recommendations Garza – Historic maximum (~350 AF/yr) Hale – Historic maximum (~300 AF/yr) Hockley – 600 AF/yr Howard – 150% of 2012 (~650 AF/yr) Martin – 150% of 2012 (~500 AF/yr) Parmer – Not relevant for purposes of joint planning (zero pumping) Swisher – 150% of historic maximum (~1,800 AF/yr)

48. Next Steps – “Final” Simulation Scenario 16 – Ogallala – 100% to 125% of 2012 pumping – ETHP – as recommended – Dockum – as recommended Complete Simulation Draft Technical Memorandum summarizing all results Cost: Not to exceed $4,000

49. ETHP and Dockum Recommendations for Scenario 16 Pumping The recommended pumping can be changed if a district wants them changed Due to other GMA commitments, actual work won’t begin until February – Changes to ETHP and Dockum pumping can be made through end of January – Please coordinate through Jason Coleman

50. Next Steps – Preliminary Explanatory Report Incorporate Scenario 16 into documentation of the 9 factors Complete Draft of Preliminary Explanatory Report Provide Draft to GMA 2 representatives by end of February Discuss at GMA 2 meeting in mid-March Cost: Not to exceed $11,000

51. Next Steps – Other Aquifers Recommend designation as not relevant for purposes of joint planning – Edwards-Trinity (Plateau) – Pecos Valley – Seymour Prepare required documentation by end of February Discuss at meeting in mid-March Cost: Not to exceed $2,000

52. Next Steps – GMA 2 Meetings Mid-March – Discuss Scenario 16 – Discuss Draft of Preliminary Explanatory Report – Discuss Documentation of Aquifers that are not relevant for purposes of joint planning Mid-April – Revised Preliminary Explanatory report – Vote on Proposed DFC – Cost: Not to exceed $4,000

53. Administrative/Invoicing Discussion Proposal dated September 15, 2014 – Three phases proposed – Firm cost estimate for Phase 1 (completed) – Range of costs for Phase 2 and 3 – Discuss initial task of Phase 2

54. Original Proposal Proposal of September 15, 2014 covered 3 phases: – Initial data gathering, DFC strategy, and HPAS review (completed) – Technical assistance in developing Proposed DFC (deadline is May 1, 2016) – Technical assistance after Proposed DFC is adopted

55. Original Proposal Proposal of September 15, 2014 covered 3 phases: – Initial data gathering, DFC strategy, and HPAS review (completed) – Technical assistance in developing Proposed DFC (deadline is May 1, 2016) – Technical assistance after Proposed DFC is adopted

56. Technical Assistance in Developing Proposed DFC Initial cost estimate was $20,000 to $40,000 – Attend GMA 2 meetings – Completing model runs – Complete work associated with nine factors – Prepare draft explanatory report

57. Budget Summary Initial cost estimate was $20,000 to $40,000 – Initial Simulations = $9,000 (completed) – Scenario 16 = $4,000 – Draft Explanatory Report = $11,000 – Not Relevant documentation = $2,000 – Final work associated with mid-April meeting = $4,000 Total to date and proposed is $30,000

58. Next Invoice Breakdown Associated with Initial Simulations DistrictAddressContactEmail Allocation (%) Approximate Invoice High Plains 2930 Ave. Q Lubbock, TX 79411 Jason Coleman jason.coleman@hpwd.com62.415,616.85 Llano Estacado 200 SE Ave. C Seminole, TX 79360 Lori Barnes leuwcdlb@gmail.com7.80702.11 Mesa Box 497 Lamesa, TX 79331 Harvey Everheart harvey.everheart@gmail.com4.95445.81 Permian Basin Box 1314 Stanton, TX 79782 Leatrice Adams permianbasin@sbcglobal.net8.72784.43 Sandy Land Box 130 Plains, TX 79355 Amber Blount amber@sandylandwater.com8.22739.39 South Plains Box 986 Brownfield, TX 79316 Lindy Harris lindy@spuwcd.org7.90711.43 Totals1009,000.00

59. Questions and Discussion Bill Hutchison 512-745-0599 billhutch@texasgw.com