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Springflow Benefits for Pumping Forbearance East and West of Cibolo Creek Edwards Aquifer Habitat Conservation Plan Prepared for: Stakeholder Committees: ASR and VISPO Work Groups. Prepared by: Larry Land, P.E . and Maureen Reilly, P.E. (CA)
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Springflow Benefits for Pumping Forbearance East and West of Cibolo CreekEdwards Aquifer Habitat Conservation Plan Prepared for:Stakeholder Committees: ASR and VISPO Work Groups Prepared by:Larry Land, P.E. and Maureen Reilly, P.E. (CA) Sam Vaugh, P.E. and Phyllis Stanin, P.G.(CA)July 31, 2014
Topics of Discussion • Purpose and Scope • Technical Approach and Assumptions • Modeling Analyses • Summary • Conclusions
Purpose and Scope PURPOSE: Establish the Springflow Benefits of ASR Leases and VISPO Forbearance Agreements East and West of Cibolo Creek SCOPE: Test and Evaluate One Conceptual Scenario
Technical Approach and Assumptions • Tasks • Estimate Availability of Potential Forbearance Agreements for ASR Leases or VISPO East and West of Cibolo Creek • Selected 10,000 acft/yr of IRP for Test and Evaluation • East of Cibolo: 69% from Comal County and 31% from Hays County • West of Cibolo: 60% from Medina County and 40% from Uvalde County • NOTE: 10,000 acft/yr is 13.8 cfs
Technical Approach and Assumptions(Continued) • Tasks (Continued) • Applications of Edwards Aquifer Model • Baseline Scenario • Prepare a Baseline Pumping Dataset for 200,000 acft/yr. Distribution within County is a Prorated Reduction of IRP. Monthly Distribution is Based on Use Type • Turn OFF Critical Period Management Controls • Run the Model
Technical Approach and Assumptions(Continued) • Tasks (Continued) • Applications of Edwards Aquifer Model (Continued) • East of Cibolo Creek Scenario • Prepare a Pumping Data Set with a Forbearance of up to 10,000 acft/yr • Run the Model • West of Cibolo Creek Scenario • Prepare a Pumping Data Set with a Forbearance of up to 10,000 acft/yr • Run the Model
Technical Approach and Assumptions(Continued) • Tasks (Continued) • Applications of Edwards Aquifer Model (Continued) • Calculate Springflow Benefits to Comal and San Marcos Springs • Deliverables, Meeting and Schedule • Powerpoint • Presentation to Work Groups
Flowpaths and Forbearance (acft/yr) East of Cibolo 3,100 6,900 West of Cibolo 6,000 4,000 Source: EAA
Springs in MODFLOW Discharge from Springs • Notes: • Hueco Springs is not in model. • Barton Springs is lumped in with Colorado River and simulated as a “River”. • Las Moras Springs is considered to be insignificant for purposes of this study.
Groundwater Modeling Results • Hydrographs at Springs and Index Wells • Difference between Baseline Scenario and East and West of Cibolo Scenarios • Distribution of Springflow Benefits from Forbearance • Efficiency of Forbearance to Springs
Forbearance BenefitComal and San Marcos 5.6 3.9 8.8 0.4
Distribution of Forbearance Springflow BenefitScenario 1 (East of Cibolo) Leona San Antonio and San Pedro Comal San Marcos
Distribution of Forbearance Springflow BenefitScenario 2 (West of Cibolo) San Antonio and San Pedro Leona Comal San Marcos
Summary • Benefit to Minimum Springflow • Comal Springs • Eastern Forbearance (Scenario 1): +5 cfs • Western Forbearance (Scenario 2): +10 cfs • San Marcos Springs • Eastern Forbearance (Scenario 1): +10 cfs • Western Forbearance (Scenario 2): +0 cfs
Summary • Benefit to Long-Term Average Springflow • Comal Springs • Eastern Forbearance (Scenario 1): +3.9 cfs • Western Forbearance (Scenario 2): +5.6 cfs • San Marcos Springs • Eastern Forbearance (Scenario 1): +8.8 cfs • Western Forbearance (Scenario 2): +0.4 cfs
Conclusions • Forbearance in Comal and Hays Counties (Scenario 1) • About 28% of the Flow Benefit goes to Comal Springs, 64% to San Marcos Springs, and 3% to Other Springs • About 5% goes to Storage (higher water levels), Los MorasSprings and boundaries • Forbearance in Medina and Uvalde Counties: (Scenario 2) • About 41% of the Flow Benefit goes to Comal Springs, 3% to San Marcos Springs, and 44% to Other Springs • About 12% goes to Storage (higher water levels), Los Moras Springs and boundaries • Results are Consistent with the Flowpath Map in Slide 15
Discussion Questions & Answers