Sponsored by:

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Edwards Aquifer Recharge Enhancement Initiative
for Four New Recharge Enhancement Projects

• Sponsored by
• San Antonio Water System
• Nueces River Authority
• Guadalupe-Blanco River Authority
• San Antonio River Authority

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Regional Setting
City of Corpus Christi
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Recharge Projects in Nueces River Basin
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Existing Recharge Projects
View of Middle Verde Creek Recharge Project
View of Parkers Creek Recharge Project Looking
Upstream fromDam Showing Outlet Structure
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How Recharge Projects Work
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Typical Stream at Recharge Project
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Capacities of Recharge Projects
Capacity(acft)
17,500
Frio
8,750
Sabinal
2,800
Hondo
3,600
Verde
32,650
Total
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Size of Outlet Pipes andReservoir Operations
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Additional Edwards Aquifer Recharge
Existing Long-Term Average Recharge653,000
acft/yr
Recharge Enhancement 48,000 acft/yr (7.3)
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Summary of Enhanced Recharge (1934 1996)
400,000
350,000
300,000
250,000
200,000
Total Enhanced Recharge (acft)
Average 48,000 acft/yr
150,000
100,000
Drought Average (1947 1956) 8,900
Critical Drought 5,400
50,000
0
1934
1936
1938
1940
1942
1944
1946
1948
1950
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
Year
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Summary of Effects of Recharge Damsin Nueces
River Basin

• Downstream Run-of-the-River Water Rights
• Well Levels in Carrizo Aquifer
• Firm Yield of CCR/LCC Reservoir System
• System Storage in CCR/LCC System
• Nueces Bay Inflows

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Run-of-the-River Water Rights Location Map
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Example Pass-Throughs toHondo Creek Water Rights
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Selected Carrizo Aquifer Monitoring Well
LocationsSouth Central Texas Regional Water Plan
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Selected Carrizo Aquifer Monitoring Well
HydrographsSouth Central Texas Regional Water
Plan
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Summary of Impacts to Firm Yield of CCR/LCC
Reservoir System(Impacts Shown Do Not Include
Mitigation)
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Water Supply and Demand forCorpus Christi
Service Area(From Regional Water Plan)
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Comparison of CCR/LCC System Storage with and
without Recharge Dams(Without Mary Rhodes
Pipeline)
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Comparison of CCR/LCC System Storage with and
without Recharge Dams(With Mary Rhodes Pipeline)
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Comparison of CCR/LCC System Storage Frequency
with and without Recharge Dams(Without Mary
Rhodes Pipeline)
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Comparison of CCR/LCC System Storage Frequency
with and without Recharge Dams(With Mary Rhodes
Pipeline)
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Nueces Bay Inflow Frequency with and without
Recharge Dams(Without Mary Rhodes Pipeline)
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Nueces Bay Inflow Frequency with and without
Recharge Dams(With Mary Rhodes Pipeline)
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Annual Nueces Bay Inflow with and without
Recharge Dams(Without Mary Rhodes Pipeline)
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Annual Nueces Bay Inflow with and without
Recharge Dams(With Mary Rhodes Pipeline)
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Median Monthly Nueces Bay Inflow with and
without Recharge Dams(Without Mary Rhodes
Pipeline)
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Median Monthly Nueces Bay Inflow with and
without Recharge Dams(With Mary Rhodes Pipeline)
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Drought Effects
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Channel Losses for Frio River for Storm of
October 27 28, 1996
20,000
18,000
Frio R. Tributaries, Near Hwy 90 54,720
acft 100
16,000
14,000
12,000
10,000
Average Daily Flow (cfs)
Frio R., Derby 2 Day Lag from Hwy 90 19,810
acft 36 of Flow at Hwy 90
8,000
6,000
Frio R., Tilden 7 Day Lag from Hwy 90 11,040
acft 20 of Flow at Hwy 90
4,000
2,000
0
10/22/96
10/27/96
11/1/96
11/6/96
11/11/96
11/16/96
Date
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Summary of Benefits of Recharge Dams

• Additional Supply / Pumpage from Edwards Aquifer
• Additional Springflow and Guadalupe River Flows
• High Well Levels in Edwards Aquifer
• Reductions in Drought Management Restrictions
• Economical Water Supply

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Benefits of Additional Recharge
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Springflow Benefits
30
25 cfs (Long-Term)
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20
19 cfs (Initial)
Increase in Springflow (cfs)
15
10
5
0.52 cfs
0.25 cfs
0
San Pedro/
Comal
San Marcos
San Antonio
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Well Level Benefits and Reductions in Drought
Management Restrictions
Average Increase in Well Levels
Uvalde County
Medina County
Bexar County
11 Feet
7 Feet
1 Foot
Reductions in Percent of Time County is in
Drought Management Restrictions
-25
-6
-4
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Benefits Outweigh Impacts
48,000
50,000
45,000
40,000
35,000
30,000
Acre-Feet/Year
25,000
20,000
15,000
10,000
4,600 4,900
2,500
5,000
0
Average Recharge
Nueces Estuary
2030 CCR/LCC System
Enhancement
Inflow Reductions
Yield Reduction (Will be Mitigated)
(Median)
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Cost of Recharge Projects(mid-1999 prices)
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Cost of Water Compared to Other Sources
Unit Cost of Firm Water for Recharge Enhancement
Projects(360 per acft)
50 per acft
770per acft
1,050 per acft
3,300 per acft
Range of Costs of Comparable Water Supply
Options As Determined During Region L SB1
Planning Study
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Summary of Benefits of Recharge Enhancement
Projects

• Additional Aquifer Pumpage of 21,440 acft/yr
• Increases Springflows
• Increases Well Levels
• Reduces Time in Drought Management
• Downstream Effects will be Mitigated
• Low Cost Supply

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