Prepared by: Larry Land, P.E . and Maureen Reilly, P.E. (CA)
description
Transcript of Prepared by: Larry Land, P.E . and Maureen Reilly, P.E. (CA)
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) Sam Vaugh, P.E. and Phyllis Stanin, P.G.(CA)
July 31, 2014
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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
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Technical Approach and Assumptions
Tasks
1. Estimate Availability of Potential Forbearance Agreements
for ASR Leases or VISPO East and West of Cibolo Creek
a) 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
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Technical Approach and Assumptions(Continued)
Tasks (Continued)
2. Applications of Edwards Aquifer Model
a) 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
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Technical Approach and Assumptions(Continued)
Tasks (Continued)
2. Applications of Edwards Aquifer Model (Continued)
b) East of Cibolo Creek Scenario
• Prepare a Pumping Data Set with a Forbearance of up
to 10,000 acft/yr
• Run the Model
c) West of Cibolo Creek Scenario
• Prepare a Pumping Data Set with a Forbearance of up
to 10,000 acft/yr
• Run the Model6
Technical Approach and Assumptions(Continued)
Tasks (Continued)
2. Applications of Edwards Aquifer Model (Continued)
d) Calculate Springflow Benefits to Comal and San Marcos
Springs
3. Deliverables, Meeting and Schedule
a) Powerpoint
b) Presentation to Work Groups
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Flowpaths and Forbearance (acft/yr)
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Source: EAA
4,000 6,000
6,900
3,100
West of Cibolo
East of Cibolo
Springs in MODFLOW
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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
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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
J-17 and J-27
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Comal and San Marcos
Springs
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Forbearance Benefit
Comal and San Marcos
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5.6
3.9
0.4
8.8
Forbearance BenefitComal and San Marcos Combined
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12.7
6.0
Distribution of Forbearance Springflow BenefitScenario 1 (East of Cibolo)
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Leona San Antonio and San Pedro
Comal
San Marcos
Distribution of Forbearance Springflow BenefitScenario 2 (West of Cibolo)
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San Antonio and San Pedro
San Marcos
Comal
Leona
Summary of Forbearance Benefit to Springs
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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
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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
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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 Moras
Springs 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
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Questions &Answers