Hydrogeologic Assessment of the Uvalde Pool of the Edwards Aquifer by dffhrtcv3

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									  Hydrogeologic Assessment of the
 Uvalde Pool of the Edwards Aquifer
with Comparison to San Antonio Pool




                 Prepared by


      Matthew M. Uliana, Ph.D., P.G.
              In association with

          Robert S. Kier Consulting




                     For




                June 25, 2004




                                       1
                                          Introduction
For the purpose of this report, the Edwards aquifer is separated into the Uvalde pool, defined as the
westernmost part of the aquifer in Uvalde and Kinney counties, and the San Antonio pool to the east
(Figure 1). Water levels in the Uvalde Pool are generally about 200 feet higher than those in the San
Antonio Pool, and groundwater in the Edwards aquifer tends to flow from the Uvalde Pool on the
west to the San Antonio Pool on the east. The Uvalde Pool is distinguished from the San Antonio
Pool because water levels in the western part of the aquifer appear to be less variable than those in
the San Antonio Pool. Maclay and Land (1989) have concluded that these two pools of the aquifer
are separated by a series of barrier faults in the subsurface that impede the flow of groundwater
from the west to the east. These faults create a structural feature known as the “Knippa Gap”,
named for its proximity to the town of Knippa, Texas, that limits the easterly flow of groundwater
and causes it to accumulate in the Uvalde Pool, resulting in decreased variability in water levels in
that part of the aquifer.
The objective of this report is to compare and contrast the hydrogeologic characteristics of each part
of the aquifer based on historical water level data and estimates of recharge to, and discharge from,
the aquifer. The results of this analysis can be used to evaluate the potential for future use of
irrigation water rights in Uvalde County for transfer to Bexar County.

                                          Data Sources
Estimates of annual recharge to the Edwards aquifer (Table 1) and annual discharge from the
aquifer (Table 2) were obtained from the USGS (Slattery and Thomas, 2003). Annual highest and
lowest water levels in selected observation wells from 1934 to 2002 (Table 3) were obtained from
the Edwards Aquifer Authority Hydrologic Data Report for 2002 (EAA, 2003). Water level data for
index wells J-17 and J-27, taken on approximately monthly intervals from 1940 to 2002 (Figure 2)
were obtained from the U.S. Geological Survey (USGS) via the NWISWeb National System
hydrology data website.

Comparison of Recharge and Discharge in Uvalde Pool to the San Antonio Pool
The majority of recharge to the Edwards aquifer is through the beds of losing streams that flow over
the recharge zone (Figure 3a). Estimates of annual recharge to the aquifer are calculated using the
method developed by Puente (1978). This method is based on measurements of stream discharge in
each of the major river basins crossing the recharge zone. Using this method, average annual
recharge to the Edwards aquifer, from 1934 to 2002, is approximately 700,000 ac-ft (Table 1).
Please note that a negligible amount of recharge enters the aquifer from sub-basin 8 (Guadalupe
River Basin); therefore, this basin was not included in Table 1.
Assuming that the boundary between the Uvalde and San Antonio pools is roughly at the
Uvalde/Medina county line, the drainage basins that contribute recharge to the Uvalde pool include
the Nueces and West Nueces basins, the Frio and Dry Frio basins, and the Sabinal River basin
(referred to on the map in Figure 3a as sub-basins 1,2, and 3, respectively). The sum of the average
annual recharge estimates to each of these basins is 298,400 ac-ft, or about 43% of the total
recharge to the aquifer.
More detailed studies of groundwater flow paths in the Edwards aquifer by Maclay and Land (1989)
and Kuniansky et al. (2001) indicate that a westward component of flow exists in the recharge zone
in Uvalde and Medina counties (Figure 3b). This suggests that some of the water recharging


                                                                                                    2
through the area between the Sabinal and the Medina river basins (sub-basin 4) is flowing into the
Uvalde Pool before it turns east to flow towards the San Antonio Pool and Bexar County. If
recharge from sub-basin 4 is added to the three other river basins contributing recharge to the
Uvalde Pool, the total recharge to the pool increases to 409,100 ac-ft, or 58% of the total recharge to
the Edwards aquifer. With our current understanding of the aquifer, it is not possible to determine
exactly how much of the water from sub-basin 4 is flowing into the Uvalde pool; however, these
data suggest that at least 50% of the total recharge to the Edwards aquifer occurs in the Uvalde
Pool.
Estimates of historical annual discharge from the aquifer by county (Table 2) were used to
determine the relative amounts of discharge from each pool of the aquifer. From 1934 to 2002, the
average annual discharge from the aquifer, as reported by Slattery and Thomas (2003), was 676,364
ac-ft with 45% from well pumpage and the remainder from spring discharge. Average annual
discharge from the Uvalde Pool, defined here as the combined discharge from Kinney and Uvalde
counties, was 71,351 ac-ft, or 11% of total aquifer discharge. During the periods of highest
discharge from these two counties (1984-1985 and 1988-1989), discharge exceeded 156,000 ac-ft
per year, and the relative discharge from the Uvalde pool ranged from 17%-22% of the total. These
values indicate that, although the Uvalde Pool receives about half of the recharge to the aquifer, the
overwhelming majority of discharge from the aquifer is from the San Antonio pool. This
relationship is true even during periods of high pumpage from the aquifer. These results suggest that
pumpage from the aquifer may not be distributed in the most efficient manner and that transfer of
water from the Uvalde Pool to the San Antonio Pool may be an appropriate way of better managing
the aquifer resources.

                            Historical Index Well Water Levels
Figure 2 is a time-series graph of index well water levels from 1940 through 2003. Each index well
is used to monitor water levels in their respective counties and determine Critical Period
Management (CPM) pumping restrictions based on specific water levels that trigger various CPM
stages. These water levels are shown on the graph as dashed lines marked Stage I, Stage II, and
Stage III. Bexar County has three CPM levels which respectively represent aquifer pumping
restrictions of 5%, 10%, and 15%. These restrictions are triggered when the J-17 index well reaches
levels of 650 feet, 640 feet, and 630 feet, respectively. Uvalde County has only one CPM stage
(15% pumping restriction) that is triggered when J-27 reaches a level of 845 feet.
The graph shows that the J-17 index well in Bexar County exhibits much greater variability than the
J-27 index well in Uvalde County. On an average annual basis, water levels in J-27 vary less than
10 feet, compared to a variance of over 25 feet for J-17 (Table 3). The graph also indicates that
water levels in index well J-27 have not reached levels that would trigger CPM restrictions since
1958. During that same period index well J-17 reached levels that would have triggered CPM
restrictions in 22 different years (1962, 1963, 1964, 1965, 1966, 1967, 1969, 1971, 1980, 1982,
1983, 1984, 1985, 1986, 1988, 1989, 1990, 1991, 1996, 1997, 1998, and 2000).
Figures 4 and 5 are time-series graphs from 1960 to 2002 that can be used to compare index well
water levels to recharge and discharge in the two pools of the Edwards aquifer. Figure 4 shows that,
during this period, total discharge from the San Antonio Pool has exceeded recharge to the pool in
every year except 2002. Water levels in J-17 appear to correlate well to recharge; years of high
recharge are associated with high water levels in the index well and vice versa. Figure 5 indicates
that, for all but 2 years during the same period, recharge in the Uvalde Pool has exceeded discharge.
Recharge in the Uvalde Pool was much more variable than recharge in the San Antonio Pool, yet J-


                                                                                                     3
27 water levels were much less variable than those in J-17. This indicates that the Uvalde Pool has
much greater stability, and suggests that the Uvalde Pool could sustain greater pumpage without
incurring CPM restrictions, especially during wet years when historic recharge has greatly exceeded
discharge.
In the Uvalde Pool, the period 1 January 1984 through 31 December 1985 (see shaded box a on
Figure 5) exhibited the highest discharge of any two-year period (313,800 ac-ft). The two
preceding years and the first year of this period (i.e., 1982-1984) were years of low recharge
(254,700 ac-ft, 228,100 ac-ft, and 99,700 ac-ft, respectively) that were well below the Uvalde Pool
annual recharge average (409,100 ac-ft). During this period, water levels in J-27 did not reach CPM
restriction trigger levels (Figure 5). Figure 5 also shows that, while high pumping levels persisted
through the end of 1985, relatively high recharge in 1985 (492,000 ac-ft) caused water levels in J-27
to recover to above-average levels by the end of the year.
1 January 1988 through 31 December 1989 (see shaded box b on Figure 5) also exhibited very high
discharge (313,600 ac-ft), and was also associated with a period of very low annual recharge
(346,100 ac-ft). As figure 5 indicates, water levels in J-27 did not trigger CPM restrictions during
this period of extreme stress on the aquifer.
During both of these periods of high stress on the Uvalde Pool, water levels in J-17 did reach levels
that triggered CPM restrictions (Figure 4). This suggests that, during periods of low recharge,
increasing discharge from the Uvalde Pool and transferring that water to Bexar County to reduce
stress on that part of the Edwards aquifer could be a reasonable method for managing the aquifer.
Since the end of the 1980’s, total discharge from the Uvalde Pool has decreased (Figure 6). From
1976 through 1990, annual discharge from the Uvalde Pool averaged 133,433 ac-ft. From 1991
through 2002, average annual discharge was 90,892 ac-ft; a reduction of 42,542 ac-ft or 32%. This
reduction in discharge is due to unused irrigation permits held by Uvalde County landowners. As
the data show, the Uvalde Pool could sustain the 1980’s level of pumping without triggering CPM
restrictions in Uvalde County, even during years of low recharge.
According to a report by the Institute for Economic Development at the University of Texas at San
Antonio (IED, 2002), there is a surplus of irrigation permits in Uvalde County of more than 41,000
ac-ft per year that could be pumped from the Uvalde Pool and piped to San Antonio to help meet
their water needs. Using these otherwise unused irrigation permits for municipal transfers to Bexar
County could reduce the stress on the San Antonio Pool and potentially limit the amount of time
that Bexar County spends in CPM restrictions without severely lowering water levels in the Uvalde
Pool.

           Comments on Previous Edwards Aquifer Groundwater Models
The previous report by Uliana (2004) is a review of a series of groundwater models of the Edwards
aquifer, based on the Texas Water Development Board’s (TWDB) GWSIM-IV model (Klemt et al.,
1979, Thorkildsen and McElhaney, 1992), that were used by HDR Engineering, Inc. (HDR) to
evaluate the potential of future development in the Uvalde Pool. Uliana (2004) pointed out
numerous shortcoming in the general model approach, the model input files, and the model results,
and concluded that the model was not effectively simulating the aquifer and could not be used to
make decisions on future development of the aquifer. Specific shortcomings included uncertainties
about the recharge input files in the model, inconsistencies in the application of pumping cells in the
model, and excessive calibration error at the J-27 well.



                                                                                                     4
Uliana (2004) reported that the total amount of annual recharge applied to the model in the Uvalde
Pool was 230,906 ac-ft. This is considerably less than the 409,100 ac-ft/year stated in this report.
The main reason for this discrepancy is that the determination of model recharge in the previous
report was based on the total amount of recharge applied to the model cells in Uvalde and Kinney
county, while the actual recharge to the aquifer stated in this report was determined based on the
recharge estimates to the river basins crossing the recharge zone, assuming that aquifer flow paths
will carry some of the recharge from Medina County into the Uvalde Pool. The first three recharge
sub-basins (Figure 3a) roughly correspond to the Uvalde Pool model cells assumed in the previous
report; the aquifer flow paths as shown in Figure 3b indicate that there is also a contribution from
sub-basin 4 that was not accounted for in the determination of model recharge. In a sense, this is not
really a straightforward comparison, and the discrepancy does not necessarily mean that the
recharge values applied to the model do not accurately represent the recharge estimates stated by the
U.S. Geological Survey. However, Uliana (2004) does identify a model-wide discrepancy between
total aquifer recharge applied to the model and total aquifer recharge as reported in Klemt et al.
(1979).
Figure 5 suggests that historical water level variations in the Uvalde Pool are more dependant upon
variations in recharge rather than discharge. The figure also shows that low aquifer water levels
(e.g., in 1984) can respond quickly to periods of above-average recharge (e.g., 1985 and 1986) and
recover to levels far above average. This indicates a high sensitivity of the system to variations in
recharge, and demands that models of the aquifer have verifiable methods for developing recharge
inputs. The responsiveness of the Uvalde Pool to recharge rates supports Uliana’s (2004) concerns
about the lack of documentation of the recharge input files in the models developed by HDR.

                                           Conclusions
In this report, the historical hydrogeologic response of the Uvalde Pool of the Edwards aquifer is
compared to the San Antonio Pool of the aquifer. Historical estimates of aquifer recharge and
discharge, as well as water levels in index wells in each pool, were analyzed and compared. The
Uvalde Pool receives approximately half of the total recharge to the aquifer, but historically has
experienced only about 10% of the total discharge from the aquifer. This suggests that redistribution
of pumping from the aquifer could be an effective way of managing the resource. Historical water
level data from the index wells in each pool indicate that the Uvalde Pool has exhibited much less
variability than the San Antonio Pool. Throughout the past 45 years, even during the periods of
highest discharge and lowest recharge, index well J-27 in Uvalde County did not reach levels that
would have triggered CPM restrictions if such restrictions were in place throughout that period.
During the same 45-year period, water levels in J-17 in Bexar County triggered CPM restrictions in
22 different years. This suggests that the Uvalde Pool could sustain greater pumpage without
incurring CPM restrictions.
Discharge from the Uvalde Pool was highest between 1976 and 1990 and has decreased over the
past 12-13 years, primarily due to unused irrigation permits held by Uvalde County landowners.
The data indicate that the Edwards aquifer in the Uvalde Pool was not experiencing severe impacts
during the period of maximum discharge. These results suggest that using these irrigation permits
for municipal transfers to Bexar County could alleviate some of the stresses on the aquifer in Bexar
County and potentially reduce the amount of time that the county spends in CPM restrictions.
The findings presented in this report support the conclusions of a previous report by the author
(Uliana, 2004) which discussed a series of groundwater models used to evaluate the response of the
Uvalde Pool to additional pumping and water transfers. The results presented here emphasizes the


                                                                                                    5
high sensitivity of the Uvalde Pool to changes in recharge, and indicate that any model of the
system must have verifiable recharge inputs. The lack of documentation and verification of the
recharge inputs to the models reviewed in Uliana (2004) is a primary reason for not using the results
of those models.
An evaluation of the potential yield of the Uvalde Pool, and the possible impacts of transferring
water from the irrigation permits, will require more detailed quantitative analysis and the use of the
Texas Water Development Board’s Edwards Aquifer Groundwater Availability Model (GAM).
However, this report indicates that the historical data support the possibility of transfer of Edwards
aquifer water from Uvalde County to Bexar County, and such transfers could be considered in
future through use of the GAM.

                                            References
EAA, 2003, Edwards Aquifer Authority Hydrogeologic Data Report For 2002: Edwards Aquifer
      Authority, 134 p.
IED, 2002, The economic impact of lease payments for irrigation water rights in Uvalde County:
      unpublished report prepared for EdwardsWater.com by the Institute for Economic
      Development at the University of Texas at San Antonio, 17 p.
Klemt, W. B., Knowles, T. R., Edler, G. R., and Sieh, T. W., 1979, Ground-Water Resources and
       Model Applications for the Edwards (Balcones Fault Zone) Aquifer in the San Antonio
       Region: Texas Water Development Board Report 239, 88 p.
Kuniansky, E.L., Fahlquist, L., and Ardis, A,F., 2001, Travel Times Along Selected Flow Paths of
      the Edwards Aquifer, Central Texas: U.S. Geological Survey Water-Resources
      Investigations Report 01-4011, p. 69-77
Maclay, R.W., and Land, L.F., 1989, Simulation of flow in the Edwards Aquifer, San Antonio
      Region, Texas, and refinement of storage and flow concepts: U.S. Geological Survey Water-
      Supply Paper 2336, 48 p.
Puente, C., 1978, Method of estimating natural recharge to the Edwards Aquifer in the San Antonio
       area, Texas: U.S. Geological Survey Water-Resources Investigations Report 78-10, 38 p.
Slattery, R.N. and Thomas, D.E., 2003, Recharge to and discharge from the Edwards Aquifer in the
        San Antonio Area, Texas, 2002: U.S. Geological Survey Report, 4 p.
Thorkildsen, D., and McElhaney, P., 1992, Model Refinement and Applications for the Edwards
       (Balcones Fault Zone) in the San Antonio Region Texas: Texas Water Development Board
       Report 340, 32 p.
Uliana, M.M., 2004, Evaluation of the GWSIM-IV model studies assessing potential development
       of the Uvalde Pool of the Edwards aquifer by HDR Engineering, Inc.: unpublished report
       prepared for EdwardsWater.com by Robert S. Kier Consulting, 8 p., 3 appendices.




                                                                                                    6
                                APPROXIMATE LOCATION
                                OF BOUNDARY BETWEEN
                               THE UVALDE POOL AND THE
                                  SAN ANTONIO POOL




Figure 1. Map of the Edwards aquifer showing the approximate location of the boundary between the Uvalde Pool
                       and the San Antonio Pool (after Thorkildsen and McElhaney, 1992)
                                                    Figure 2. Graph of groundwater levels in Edwards aquifer index wells, with associated
                                                            Critical Period Management restriction levels, from 1940 through 2003
                          900                                                                                                                           775


                                        Uvalde County Index Well (J-27)
                                          State Well # YP-69-50-302
                          875                                                                                                                           750




                          850                                                                                                                           725
                                   J-27 STAGE III



                          825                                                                                                                           700




                          800                                                                                                                           675
                                                                                                                                                              J-17 ELEVATION ASL (ft)




J-27 ELEVATION ASL (ft)
                          775      J-17 STAGE I                                                                                                         650

                                   J-17 STAGE II

                                   J-17 STAGE III
                          750                                                                                                                           625


                                                                          Bexar County Index Well (J-17)
                                                                            State Well # AY-68-37-203
                          725                                                                                                                           600
                            1940       1945        1950     1955          1960      1965      1970         1975   1980   1985   1990   1995   2000   2005
a)



                                                                       9
                                                 8

                 1              2                            7
                                                  5
                                                                   6
                                      3    4




b)




                                                                       0   10       20   30
                                                                            miles



     Figure 3. a) Drainage basins used in estimates of recharge to the Edwards aquifer (modified
      from Puente, 1978; b) flow paths in the aquifer (based on Maclay and Land (1989) and
                                      Kuniansky et al. (2001))
                                                     Figure 4. Comparison of Index Well J-17 water levels to annual recharge to, and discharge
                                                                                   from, the San Antonio Pool
                                       720


                                       700


                                       680


                                       660
                                                                               STAGE I
                                       640                                     STAGE II




        J-17 ELEVATION ASL (ft)
                                                                              STAGE III
                                       620
                                          1960
                                  1,600,000           1965        1970         1975         1980         1985         1990        1995           2000   2005



                                  1,200,000

                                                   TOTAL
                                                 DISCHARGE
                                   800,000




        TOTAL (ac-ft)
                                   400,000


                                                                             RECHARGE




ANNUAL RECHARGE & DISCHARGE
                                         0
                                          1960        1965        1970         1975         1980         1985         1990        1995           2000   2005
                                                                                             DATE
                                                     Figure 5. Comparison of Index Well J-27 water levels to annual recharge to, and discharge
                                                                                     from, the Uvalde Pool
                                   920
                                                                                                        a         b
                                   900


                                   880


                                   860

                                             STAGE III
                                   840




J-27 ELEVATION ASL (ft)
                                   820
                                      1960
                              1,600,000              1965        1970         1975         1980         1985          1990        1995           2000   2005




                              1,200,000

                                                               RECHARGE


                               800,000




        TOTAL (ac-ft)
                               400,000
                                                                        TOTAL
                                                                     DISCHARGE




ANNUAL RECHARGE & DISCHARGE
                                     0
                                      1960           1965         1970         1975        1980         1985          1990        1995           2000   2005
                                                                                          DATE
                                             Figure 6. Comparison of Index Well J-27 water levels to annual discharge from the Uvalde Pool
                             920


                             900


                             880


                             860

                                       STAGE III
                             840




J-27 ELEVATION ASL (ft)
                             820
                                1960
                          175,000             1965        1970         1975         1980         1985         1990         1995         2000   2005


                          150,000

                          125,000

                          100,000




         (ac-ft)
                           75,000

                           50,000




ANNUAL DISCHARGE TOTAL
                           25,000

                               0
                                1960          1965        1970         1975         1980         1985         1990         1995         2000   2005
                                                                                  DATE
                                     UVALDE POOL                                                      SAN ANTONIO POOL
           1                2           3              4                              5             6             7             9
       Nueces and       Frio and      Sabinal    Area between                       Medina    Area between    Cibolo and   Blanco River   Pool      % of    Aquifer
Year   West Nueces      Dry Frio       River     Sabinal and     Pool       % of    River     Cibolo Creek    Dry Comal     basin and     Total     Total    Total
       River basins   River basins    basin      Medina River    Total      Total   basin     and Medina     Creek basins adjacent area
                                                    basins                                    River basins
1934        8,600         27,900         7,500        19,900      63,900     36%     46,500       21,000         28,400         19,800    115,700    64%      179,600
1935      411,300        192,300        56,600       166,200     826,400     66%     71,100      138,200        182,700         39,800    431,800    34%    1,258,200
1936      176,500        157,400        43,500       142,900     520,300     57%     91,600      108,900        146,100         42,700    389,300    43%     909,600
1937       28,800         75,700        21,500        61,300     187,300     47%     80,500       47,800         63,900         21,200    213,400    53%     400,700
1938       63,500         69,300        20,900        54,100     207,800     48%     65,500       46,200         76,800         36,400    224,900    52%     432,700
1939      227,000         49,500        17,000        33,100     326,600     82%     42,400        9,300          9,600         11,100     72,400    18%     399,000
1940       50,400         60,300        23,800        56,600     191,100     62%     38,800       29,300         30,800         18,800    117,700    38%     308,800
1941       89,900        151,800        50,600       139,000     431,300     51%     54,100      116,300        191,200         57,800    419,400    49%     850,700
1942      103,500         95,100        34,000        84,400     317,000     57%     51,700       66,900         93,600         28,600    240,800    43%     557,800
1943       36,500         42,300        11,100        33,800     123,700     45%     41,500       29,500         58,300         20,100    149,400    55%     273,100
1944       64,100         76,000        24,800        74,300     239,200     43%     50,500       72,500        152,500         46,200    321,700    57%     560,900
1945       47,300         71,100        30,800        78,600     227,800     43%     54,800       79,600        129,900         35,700    300,000    57%     527,800
1946       80,900         54,200        16,500        52,000     203,600     37%     51,400      105,100        155,300         40,700    352,500    63%     556,100
1947       72,400         77,700        16,700        45,200     212,000     50%     44,000       55,500         79,500         31,600    210,600    50%     422,600
1948       41,100         25,600        26,000        20,200     112,900     63%     14,800       17,500         19,900         13,200     65,400    37%     178,300
1949      166,000         86,100        31,500        70,300     353,900     70%     33,000       41,800         55,900         23,500    154,200    30%     508,100
1950       41,500         35,500        13,300        27,000     117,300     59%     23,600       17,300         24,600         17,400     82,900    41%     200,200
1951       18,300         28,400         7,300        26,400      80,400     57%     21,100        15,300        12,500         10,600     59,500    43%     139,900
1952       27,900         15,700         3,200        30,200      77,000     28%     25,400        50,100       102,300         20,700    198,500    72%     275,500
1953       21,400         15,100         3,200         4,400      44,100     26%     36,200        20,100        42,300         24,900    123,500    74%     167,600
1954       61,300         31,600         7,100        11,900     111,900     69%     25,300         4,200        10,000         10,700     50,200    31%     162,100
1955      128,000         22,100           600         7,700     158,400     83%     16,500         4,300         3,300          9,500     33,600    18%     192,000
1956       15,600          4,200        1,600          3,600       25,000    57%      6,300        2,000          2,200          8,200     18,700    43%       43,700
1957      108,600        133,600       65,400        129,500      437,100    38%     55,600      175,600        397,900         76,400    705,500    62%    1,142,600
1958      266,700        300,000      223,800        294,900    1,085,400    63%     95,500      190,900        268,700         70,700    625,800    37%    1,711,200
1959      109,600        158,900       61,600         96,700      426,800    62%     94,700       57,400         77,900         33,600    263,600    38%      690,400
1960       88,700        128,100       64,900        127,000      408,700    50%    104,000       89,700        160,000         62,400    416,100    50%      824,800
1961       85,200        151,300        57,400       105,400     399,300     56%     88,300        69,300       110,800         49,400    317,800    44%     717,100
1962       47,400         46,600         4,300        23,500     121,800     51%     57,300        16,700        24,700         18,900    117,600    49%     239,400
1963       39,700         27,000         5,000        10,300      82,000     48%     41,900         9,300        21,300         16,200     88,700    52%     170,700
1964      126,100         57,100        16,300        61,300     260,800     63%     43,300        35,800        51,100         22,200    152,400    37%     413,200
1965       97,900         83,000        23,200       104,000     308,100     49%     54,600        78,800       115,300         66,700    315,400    51%     623,500
1966      169,200        134,000        37,700        78,200     419,100     68%     50,500        44,500        66,500         34,600    196,100    32%     615,200
1967       82,200        137,900        30,400        64,800     315,300     68%     44,700        30,200        57,300         19,000    151,200    32%     466,500
1968      130,800        176,000        66,400       198,700     571,900     65%     59,900        83,100       120,500         49,300    312,800    35%     884,700
1969      119,700        113,800        30,700        84,200     348,400     57%     55,400        60,200        99,900         46,600    262,100    43%     610,500
1970      112,600        141,900        35,400        81,600     371,500     56%     68,000        68,800       113,800         39,500    290,100    44%     661,600

                            Table 1. Estimated Annual Recharge to the Edwards (Balcones Fault Zone) Aquifer
            All values in acre-feet; pool divisions are based on flow paths reported in Maclay and Land (1989) and Kuniansky et al., 2001
                                       UVALDE POOL                                                      SAN ANTONIO POOL
            1                 2           3              4                              5             6             7             9
        Nueces and        Frio and      Sabinal    Area between                       Medina    Area between    Cibolo and   Blanco River    Pool       % of    Aquifer
Year    West Nueces       Dry Frio       River     Sabinal and     Pool       % of    River     Cibolo Creek    Dry Comal     basin and      Total      Total    Total
        River basins    River basins    basin      Medina River    Total      Total   basin     and Medina     Creek basins adjacent area
                                                      basins                                    River basins

1971       263,400         212,400       39,200        155,600     670,600     72%     68,700       81,400         82,400         22,200     254,700     28%      925,300
1972       108,400         144,600       49,000        154,600     456,600     60%     87,900       74,300        104,200         33,400     299,800     40%      756,400
1973       190,600         256,900      123,900        286,400     857,800     58%     97,600      237,200        211,700         82,200     628,700     42%    1,486,500
1974        91,100         135,700       36,100        115,300     378,200     57%     96,200       68,100         76,900         39,100     280,300     43%      658,500
1975        71,800         143,600       47,900        195,900     459,200     47%     93,400      138,800        195,700         85,900     513,800     53%      973,000
1976       150,700         238,600        68,200       182,000     639,500     72%     94,500        47,900        54,300         57,900     254,600     28%      894,100
1977       102,900         193,000        62,700       159,500     518,100     54%     77,700        97,900       191,600         66,700     433,900     46%      952,000
1978        69,800          73,100        30,900       103,700     277,500     55%     76,700        49,600        72,400         26,300     225,000     45%      502,500
1979       128,400         201,400        68,600       203,100     601,500     54%     89,400        85,400       266,300         75,200     516,300     46%    1,117,800
1980        58,600          85,600        42,600        25,300     212,100     52%     88,300        18,800        55,400         31,800     194,300     48%      406,400
1981       205,000         365,200      105,600        252,100     927,900     64%     91,300      165,000        196,800         67,300     520,400     36%    1,448,300
1982        19,400         123,400       21,000         90,900     254,700     60%     76,800       22,600         44,800         23,500     167,700     40%      422,400
1983        79,200          85,900       20,100         42,900     228,100     54%     74,400       31,900         62,500         23,200     192,000     46%      420,100
1984        32,400          40,400        8,800         18,100      99,700     50%     43,900       11,300         16,900         25,900      98,000     50%      197,700
1985       105,900         186,900       50,700        148,500     492,000     49%     64,700      136,700        259,200         50,700     511,300     51%    1,003,300
1986       188,400         192,800       42,200        173,600      597,000    52%     74,700      170,200        267,400        44,500      556,800     48%    1,153,800
1987       308,500         473,300      110,700        405,500    1,298,000    65%     90,400      229,300        270,900       114,900      705,500     35%    2,003,500
1988        59,200         117,900       17,000         24,900      219,000    62%     69,900       12,600         28,500        25,500      136,500     38%      355,500
1989        52,600          52,600        8,400         13,500      127,100    59%     46,900        4,600         12,300        23,600       87,400     41%      214,400
1990       479,300         255,000       54,600        131,200      920,100    82%     54,000       35,900         71,800        41,300      203,000     18%    1,123,100
1991       325,200         421,000      103,100        315,200    1,164,500    77%     52,800       84,500        109,700        96,900      343,900     23%    1,508,400
1992       234,100         586,900      201,100        566,100    1,588,200    64%     91,400      290,600        286,600       226,900      895,500     36%    2,486,000
1993        32,600          78,500       29,600         60,800      201,500    45%     78,500       38,900         90,900        37,800      246,100     55%      447,600
1994       124,600         151,500       29,500         45,100      350,700    65%     61,100       34,100         55,600        36,600      187,400     35%      538,100
1995       107,100         147,600       34,700         62,400      351,800    66%     61,700       36,200         51,100        30,600      179,600     34%      531,300
1996       130,000          92,000        11,400         9,400     242,800     75%     42,300       10,600         14,700        13,900       81,500     25%      324,300
1997       176,900         209,100        57,000       208,400     651,400     57%     63,300      193,400        144,200        82,300      483,200     43%    1,134,600
1998       141,500         214,800        72,500       201,400     630,200     55%     80,300       86,200        240,900       104,700      512,100     45%    1,142,300
1999       101,400         136,800        30,800        57,200     326,200     69%     77,100       21,200         27,900        21,000      147,200     31%      473,400
2000       238,400         123,000        33,100        55,200     449,700     73%     53,400       28,600         48,600        34,100      164,700     27%      614,500
2001       297,500         126,700        66,200       124,100     614,500     57%     90,000      101,500        173,700        89,700       454,900    43%    1,069,400
2002        83,600         207,300        70,600       345,200     706,700     42%     93,700      175,500        593,300       150,000     1,012,500    61%    1,665,200
 AVG:      120,648         135,183       42,600        110,671      409,101    58%     62,367       71,446        112,123        44,642       290,578    42%      699,680
 MAX:      479,300         586,900      223,800        566,100    1,588,200    83%    104,000      290,600        593,300       226,900     1,012,500    74%    2,486,000
 MIN:        8,600           4,200          600          3,600       25,000    26%      6,300        2,000          2,200         8,200        18,700    18%       43,700


                       Table 1. Estimated Annual Recharge to the Edwards (Balcones Fault Zone) Aquifer (continued)
             All values in acre-feet; pool divisions are based on flow paths reported in Maclay and Land (1989) and Kuniansky et al., 2001
        UVALDE POOL                                    SAN ANTONIO POOL
Year   Kinney &    % of        Medina      Bexar        Comal         Hays        San Antonio     % of     Aquifer     Total     Total
        Uvalde    Total        County      County       County       County        Pool Total    Total      Total      Well     Spring
       Counties Discharge                                                                      Discharge            discharge discharge
1934      12,600        3%         1,300    109,300       229,100        85,600        425,300       97%    437,900    101,900   336,000
1935      12,200        2%         1,500    171,800       237,200        96,900        507,400       98%    519,600    103,700   415,900
1936      26,600          4%       1,500    215,200       261,700        93,200        571,600      96%     598,200   112,700   485,500
1937      28,300          5%       1,500    201,800       252,500        87,100        542,900      95%     571,200   120,200   451,000
1938      25,200          5%       1,600    187,600       250,000        93,400        532,600      95%     557,800   120,100   437,700
1939      18,200          4%       1,600    122,500       219,400        71,100        414,600      96%     432,800   118,900   313,900
1940      16,100          4%       1,600    116,700       203,800        78,400        400,500      96%     416,600   120,100   296,500
1941      17,900          3%       1,600    197,400       250,000       134,300        583,300      97%     601,200   136,800   464,400
1942      22,500          4%       1,700    203,200       255,100       112,200        572,200      96%     594,700   144,600   450,100
1943      19,200          4%       1,700    172,000       249,200        97,200        520,100      96%     539,300   149,100   390,200
1944      11,600          2%       1,700    166,300       252,500       135,300        555,800      98%     567,400   147,300   420,100
1945      12,400          2%       1,700    199,800       263,100       137,800        602,400      98%     614,800   153,300   461,500
1946       6,200          1%       1,700    180,100       261,900       134,000        577,700      99%     583,900   155,000   428,900
1947      13,800          2%       2,000    193,300       256,800       127,600        579,700      98%     593,500   167,000   426,500
1948       9,200          2%       1,900    159,200       203,000        77,300        441,400      98%     450,600   168,700   281,900
1949      13,200          3%       2,000    165,300       209,500        89,800        466,600      97%     479,800   179,400   300,400
1950      17,800          4%       2,200    177,300       191,100        78,300        448,900      96%     466,700   193,800   272,900
1951      16,900          4%       2,200    186,900       150,500        69,100        408,700      96%     425,600   209,700   215,900
1952      22,700          5%       3,100    187,100       133,200        78,800        402,200      95%     424,900   215,400   209,500
1953      27,500          6%       4,000    193,700       141,700       101,400        440,800      94%     468,300   229,800   238,500
1954      26,600          6%       6,300    208,900       101,000        81,500        397,700      94%     424,300   246,200   178,100
1955      28,300          7%      11,100    215,200        70,100        64,100        360,500      93%     388,800   261,000   127,800
1956      59,600         15%      17,700    229,600        33,600        50,400        331,300      85%     390,900   321,100    69,800
1957      29,000          6%      11,900    189,400       113,200       113,000        427,500      94%     456,500   237,300   219,200
1958      23,700          4%       6,600    199,500       231,800       155,900        593,800      96%     617,500   219,300   398,200
1959      43,000          7%       8,300    217,500       231,700       118,500        576,000      93%     619,000   234,500   384,500
1960      53,700          8%       7,600    215,400       235,200       143,500        601,700      92%     655,400   227,100   428,300
1961      56,500          8%       6,400    230,300       249,500       140,800        627,000      92%     683,500   228,200   455,300
1962      64,600         11%       8,100    220,000       197,500        98,800        524,400      89%     589,000   267,900   321,100
1963      51,400         10%       9,700    217,300       155,700        81,900        464,600      90%     516,000   276,400   239,600
1964      49,300         10%       8,600    201,000       141,800        73,300        424,700      90%     474,000   260,200   213,800
1965      46,800          8%      10,000    201,100       194,700       126,300        532,100      92%     578,900   256,100   322,800
1966      48,500          8%      10,400    198,000       198,900       115,400        522,700      92%     571,200   255,900   315,300
1967      81,100         15%      15,200    239,700       139,100        82,300        476,300      85%     557,400   341,300   216,100
1968      58,000          9%       9,900    207,100       238,200       146,800        602,000      91%     660,000   251,700   408,300
1969      88,500         13%      13,600    216,300       218,200       122,100        570,200      87%     658,700   307,500   351,200
1970     100,900         14%      16,500    230,600       229,200       149,900        626,200      86%     727,100   329,400   397,700

                   Table 2. Estimated Annual Discharge to the Edwards (Balcones Fault Zone) Aquifer
                                                      All values in acre-feet
                  UVALDE POOL                                   SAN ANTONIO POOL
   Year          Kinney &       % of     Medina     Bexar        Comal         Hays        San Antonio        % of     Aquifer        Total     Total
                  Uvalde       Total     County     County       County       County        Pool Total       Total      Total         Well     Spring
                 Counties    Discharge                                                                     Discharge               discharge discharge
   1971            117,000        17%      32,400    262,800       168,200        99,100        562,500         83%     679,500      406,800   272,700
   1972            112,600        15%      28,800    247,700       234,300       123,700        634,500         85%     747,100      371,300   375,800
   1973             96,500        12%      14,900    273,000       289,300       164,300        741,500         88%     838,000      310,400   527,600
   1974            133,300        15%      28,600    272,100       286,100       141,100        727,900         85%     861,200      377,400   483,800
   1975            112,000        13%      22,600    259,000       296,000       178,600        756,200         87%     868,200      327,800   540,400
   1976            136,400        16%      19,400    253,200       279,700       164,700        717,000         84%     853,400      349,500   503,900
   1977            156,500        16%      19,900    317,500       295,000       172,000        804,400         84%     960,900      380,600   580,300
   1978            154,300        19%      38,700    269,500       245,700        99,100        653,000         81%     807,300      431,800   375,500
   1979            130,100        14%      32,900    294,500       300,000       157,000        784,400         86%     914,500      391,500   523,000
   1980            151,000        18%      39,900    300,300       220,300       107,900        668,400         82%     819,400      491,100   328,300
   1981            104,200        13%      26,100    280,700       241,800       141,600        690,200         87%     794,400      387,100   407,300
   1982            129,200        16%      33,400    305,100       213,200       105,500        657,200         84%     786,400      453,100   333,300
   1983            107,700        15%      29,700    277,600       186,600       118,500        612,400         85%     720,100      418,500   301,600
   1984            156,900        22%      46,900    309,700       108,900        85,700        551,200         78%     708,100      529,800   178,300
   1985            156,900        18%      59,200    295,500       200,000       144,900        699,600         82%     856,500      522,500   334,000
   1986             91,700        11%      41,900    294,000       229,300       160,400        725,600         89%     817,300      429,300   388,000
   1987             94,900        10%      15,900    326,600       286,200       198,400        827,100         90%     922,000      364,100   557,900
   1988            156,700        17%      82,200    317,400       236,500       116,900        753,000         83%     909,700      540,000   369,700
   1989            156,900        20%      70,500    305,600       147,900        85,600        609,600         80%     766,500      542,400   224,100
   1990            118,100        16%      69,700    276,800       171,300        94,100        611,900         84%     730,000      489,400   240,600
   1991             76,600        10%      25,600    315,500       221,900       151,000         714,000        90%      790,600     436,000   354,600
   1992             76,500         7%       9,300    370,500       412,400       261,300       1,053,500        93%    1,130,000     327,200   802,800
   1993            107,500        11%      17,800    371,000       349,500       151,000         889,300        89%      996,700     407,300   589,400
   1994             95,500        12%      41,100    297,700       269,800       110,600         719,200        88%      814,800     424,600   390,200
   1995             90,800        12%      35,200    272,100       235,000       127,800         670,100        88%      761,000     399,600   361,300
   1996            117,600        17%      66,300    286,800       150,200        84,700        588,000         83%     705,600      493,600   212,000
   1997             77,000        10%      31,400    260,200       243,300       149,200        684,100         90%     761,100      377,100   383,900
   1998            113,100        12%      51,300    312,400       271,800       168,800        804,300         88%     917,600      453,500   464,100
   1999            104,000        12%      49,200    307,100       295,500       143,000        794,800         88%     898,800      442,700   456,100
   2000             89,100        12%      45,100    283,600       226,100       108,400        663,200         88%     752,300      414,800   337,500
   2001             68,600         8%      33,900    291,600       327,700       175,400        828,600         93%     890,000      367,700   529,400
   2002             74,400         8%      39,500    314,100       346,900       202,200        902,700         92%     977,100      367,200   609,900
AVG ('76-'90):     133,433        16%      41,753    294,933       224,160       130,153         691,000        84%     824,433      448,047   376,387
AVG ('91-'02):      90,892        11%      37,142    306,883       279,175       152,783         775,983        89%     866,300      409,275   457,600
AVG ('34-'02):      71,351        11%      20,512    240,067       223,726       120,809         605,113        89%      676,364     304,265   372,199
MAX ('34-'02):     156,900        22%      82,200    371,000       412,400       261,300       1,053,500        99%    1,130,000     542,400   802,800
MIN ('34-'02):       6,200         1%       1,300    109,300        33,600        50,400         331,300        78%      388,800     101,900    69,800

                    Table 2. Estimated Annual Discharge to the Edwards (Balcones Fault Zone) Aquifer (continued)
                                                               All values in acre-feet
             City Of Uvalde          Castroville            San Antonio            New Braunfels
             Uvalde County         Medina County           Bexar County            Comal County
               YP-69-50-302         TD-68-41-301           AY-68-37-203            DX-68-23-302
                  (J-27)                                       (J-17)
Year     High      Low Range    High    Low     Range   High    Low Range       High    Low     Range
  1934    ----      ----         ----    ----           675.2 666.8      8.4     ----    ----
  1935    ----      ----         ----    ----           681.3 666.8     14.5     ----    ----
  1936   876.6   876.5    0.1   ----    ----              683    676.6    6.4   ----    ----
  1937   878.1   877.1      1   ----    ----             682.1   674.9    7.2   ----    ----
  1938   875.8    874     1.8   ----    ----             681.4   673.6    7.8   ----    ----
  1939   873.4   869.6    3.8   ----    ----             674.1   665.7    8.4   ----    ----
  1940   872.3   868.5    3.8   ----    ----             671.4    661    10.4   ----    ----
  1941   875.7   867.7      8   ----    ----             682.5   668.3   14.2   ----    ----
  1942   875.8   871.9    3.9   ----    ----             685.4   669.7   15.7   ----    ----
  1943   874.5    868     6.5   ----    ----             679.6   668.5   11.1   ----    ----
  1944   869.3   866.8    2.5   ----    ----             677.6   667.1   10.5   ----    ----
  1945   870.1   865.2    4.9   ----    ----             681.9   668.8   13.1   ----    ----
  1946   867.1   862.9    4.2   ----    ----             681.2   663.6   17.6   ----    ----
  1947   870.7   867.1    3.6   ----    ----             680.7   665.8   14.9   ----    ----
  1948   868.4   860.5    7.9   ----    ----             667.7   653.7    14    624.4   624.3      0.1
  1949   871.2   859.1   12.1   ----    ----             671.6   655.6    16    626.7   624.1      2.6
  1950   871.2   861.8    9.4     687   674.9   12.1     665.4   653.8   11.6   625.2     624      1.2
  1951   861.8   846.8    15    675.2   659.9   15.3      656    640.6   15.4   624.2   622.5      1.7
  1952   846.8   834.9   11.9   663.8   649.9   13.9     650.5   633.4   17.1    623    621.5      1.5
  1953   835.2   817.8   17.4   665.1   647.7   17.4     651.5   630.5    21    623.6   621.1      2.5
  1954   836.7   823.1   13.6   660.3   642.4   17.9     646.3   628.9   17.4   623.1   620.5      2.6
  1955   834.3   824.1   10.2   649.1   635.6   13.5     638.5   624.2   14.3   621.9   619.8      2.1
  1956   834.2   814.2    20    641.6   622.3   19.3     632.2   612.5   19.7    621    613.3      7.7
  1957   840.9    811    29.9   666.1    633    33.1     653.8   624.4   29.4   624.7   620.1      4.6
  1958   866.1   840.8   25.3   704.4   665.7   38.7     679.6   653.3   26.3   626.6   624.6        2
  1959   876.1   866.2    9.9   703.8    689    14.8     677.7   661.5   16.2   627.1   625.1        2
  1960   876.9   873.1    3.8   706.3    686    20.3     679.4   657.9   21.5   627.1   624.9      2.2
  1961   878.5   875.6    2.9   710.3   693.4   16.9     681.2   663.9   17.3   627.3   625.7      1.6
  1962   878.3   867.7   10.6   703.6   676.3   27.3     675.5   646.9   28.6   626.3   623.2      3.1
  1963   869.7   860.9    8.8   689.1   659.2   29.9     665.8    635    30.8    625    621.7      3.3
  1964   860.9    849    11.9   676.3   654.8   21.5     657.1   632.8   24.3   624.1   621.6      2.5
  1965   865.8   860.3    5.5   689.6   666.8   22.8      675    645.6   29.4   626.6   623.5      3.1
  1966   867.2   860.2      7   686.1    665    21.1     668.8   642.7   26.1   625.9   623.1      2.8
  1967   867.4   856.4    11    679.4   645.2   34.2     659.7   624.9   34.8   624.6    620       4.6
  1968   873.3   864.8    8.5    702    679.2   22.8     678.3   655.9   22.4   627.2   624.6      2.6
  1969    875    866.5    8.5   694.8   670.5   24.3     676.1   642.8   33.3   626.3   623.4      2.9
  1970   876.1   871.3    4.8   700.7   678.8   21.9     677.1   650.4   26.7   627.2   624.3      2.9

   Table 3. Annual water level ranges for index wells in the Edwards-BFZ aquifer
                                        All values in feet
             City Of Uvalde          Castroville              San Antonio          New Braunfels
             Uvalde County         Medina County             Bexar County          Comal County
              YP-69-50-302          TD-68-41-301             AY-68-37-203          DX-68-23-302
                  (J-27)                                         (J-17)
 Year     High     Low Range     High    Low     Range    High    Low Range      High    Low     Range
   1971   877.7    864    13.7   701.3   646.4     54.9   674.6   627.9   46.7   626.2    621       5.2
   1972   877.8   874.6    3.2   704.6   676.7     27.9    679    651.2   27.8   626.7   624.1      2.6
   1973   881.6   874.5    7.1   731.2   690.1     41.1   696.5   665.9   30.6   629.8   626.1      3.7
   1974   881.4    876     5.4   723.8    696      27.8   689.2   660.9   28.3   629.1   625.8      3.3
   1975   882.1   879.4    2.7    721    708.2     12.8   686.9    672    14.9   629.3   626.5      2.8
   1976   884.9    876     8.9   732.4   694.9     37.5   693.1   663.8   29.3   629.4   625.8      3.6
   1977   886.2   881.3    4.9   737.8   715.3     22.5    696    675.6   20.4   630.2   627.6      2.6
   1978   882.6   875.6      7   722.4   681.7     40.7   684.1   650.1    34    628.1   624.5      3.6
   1979    882    876.1    5.9   728.2   710.3     17.9   690.5   676.4   14.1    629    627.3      1.7
   1980   879.1    868    11.1   716.1   666.8     49.3   680.3   640.8   39.5   627.5    623       4.5
   1981   881.8   867.9   13.9   723.2   698.8     24.4    686    668.6   17.4    628    625.5      2.5
   1982   881.8   876.4    5.4   717.1   682.8     34.3   680.5   645.3   35.2   627.3   623.6      3.7
   1983   877.1   871.3    5.8   698.2   667.7     30.5    670    642.1   27.9   625.6    623       2.6
   1984   873.3   856.9   16.4   684.5    642      42.5    657    623.3   33.7   624.4   619.6      4.8
   1985   876.9   862.2   14.7    699    670.7     28.3   674.5   644.1   30.4   626.8   623.3      3.5
   1986   877.8   872.2    5.6   704.6   674.2     30.4   685.6   649.8   35.8   627.7   624.1      3.6
   1987   889.1   877.9   11.2   743.5   711.1     32.4   699.2   676.9   22.3   630.4   627.2      3.2
   1988    887     878       9   725.3   679.9     45.4   684.9   647.7   37.2   627.9   623.9        4
   1989    879    866.6   12.4   695.3   650.5     44.8   663.9   626.4   37.5   624.9   620.5      4.4
   1990   872.9   861.6   11.3   679.5   640.8     38.7   658.1   622.7   35.4   624.3   620.3        4
   1991   873.8   865.4    8.4   703.8   666.1     37.7   680.3   640.5   39.8    627    623.3      3.7
   1992   885.2   872.9   12.3   743.6   704.3     39.3   703.3   680.7   22.6   630.9    627       3.9
   1993   884.9   877.3    7.6   730.2   706.6     23.6   692.8    672    20.8   629.4   626.9      2.5
   1994   ----    ----           718.6   684.1     34.5   679.2   652.1   27.1   627.2   624.7      2.5
   1995   877.2   871.1    6.1    703    681.8     21.2   676.5   651.1   25.4   626.8   624.5      2.3
   1996   874.2    859    15.2    693    650.2     42.8   664.9   627.5   37.4   625.3   621.2      4.1
   1997   882.3   868.2   14.1   700.5   672.7     27.8   677.9   648.7   29.2   626.4   623.6      2.8
   1998   880.6   868.7   11.9   717.1   669.1      48    688.9    640    48.9   629.6   622.9      6.7
   1999   880.7   876.8    3.9   716.4   682.9     33.5   686.4   656.9   29.5   628.7   624.9      3.8
   2000   878.3    868    10.3   700.4   662.5     37.9   676.7   635.5   41.2   626.8   622.2      4.6
   2001   877.2   872.7    4.5   713.4   685.9     27.5   682.8   652.8    30    628.3   624.5      3.8
   2002   883.2   876.3    6.9   732.7   685.8     46.9   697.9    650    47.9   630.2   624.6      5.6
  AVG:    872.5   863.2    9.4   702.2   672.7     29.5   675.6   649.9   25.7   626.7   623.5      3.2
MEDIAN:   876.1   867.7    8.5   703.6   674.2     27.9   678.3   650.4   26.3   626.8   623.9      3.1
  MAX:    889.1           29.9   743.6             54.9   703.3           48.9   630.9              7.7
   MIN:           811.0    2.5           622.3     12.1           612.5   10.4           613.3      0.1

 Table 3. Annual water level ranges for index wells in the Edwards-BFZ aquifer            (continued)
                                         All values in feet

								
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