Using the RGDSS Groundwater Model to Compute Response Functions
The computation of response functions for Subdistrict No. 1 involves making a set of paired model simulations using the Rio Grande Decision Support Groundwater Model (“Model”). In each pair of simulations, one simulation represents a reference case that is referred to as the historical run. The second simulation is referred to as the impact run. The term impact refers to the fact that the simulation is intended to quantify the impact of some change to historical conditions.
The Model is therefore applied in a change mode. The difference in predicted stream gains and losses calculated by subtracting the impact run from the historical run is the quantification of the impact of differences in the Model inputs between the runs.
The impact of well pumping in Subdistrict No. 1 on streams is evaluated by generating a set of model inputs that represent a different level of well pumping inside Subdistrict No. 1. Specifically, the amount of well pumping is adjusted such that the amount of consumption matches the amount of consumption of imported water quantified with the methodologies of the recharge decrees (“Imported Water Offset”). In the impact run the amount of pumping for land served by ditches without recharge decrees is zero.
The impact run for Subdistrict No. 1 is a simulation where the inputs to the model are changed inside Subdistrict No. 1 to reflect that the amount of groundwater consumptive use is equal to the Imported Water Offset. A comparison of the stream­aquifer interaction between the impact run and the historical run reflects changes in the stream flow that result from changes in the inputs.
Response Functions
In order to facilitate prediction of future stream depletions as a function of activities inside Subdistrict No. 1, a response function will be used.
The critical Model input is the difference between consumption due to well pumping and the Imported Water Offset. The Model output of interest is the impact to streams. The goal is therefore to generate a relationship between stream impacts in location, time and the amount from groundwater consumption in excess of the Imported Water Offset. This relationship is called a response function.
The response function is a fraction of the applied stress that translates to a change in stream flow at a particular location at a particular time. It is assumed that when the applied stress is changed, that the change in stream flow changes proportionally. This requires the response to be linear. The Model is, of course, nonlinear, but for moderate changes in the applied stresses the response varies close to linear.
Once the response functions are generated, by applying the model and post­processing the results, stream depletions can be readily calculated. Specifically, the response functions generated for Subdistrict No. 1 translate the annual difference between consumption of groundwater due to well pumping and the Imported Water Offsets to monthly stream depletions by stream. Therefore in order to calculate the impact of well pumping in a particular year on a particular stream for a particular month, what is required is:
1. determine the difference between consumption due to well pumping and the Imported Water Offset (in acre feet annually),
2. multiply it by the appropriate response function value, and
3. the result is the impact to the particular stream for a particular month.
Model Input Data
Consumptive use calculations are done using the StateCU program. This program uses historical irrigated area and crop information to calculate how surface and ground water would be applied and consumed. These calculations are done on a ditch service area basis. Two sets of consumptive use calculations are available. The historical use for the period 1950­2005 is contained in rg2007.dwb and represents the best estimates of historical consumptive use. An alternative scenario which considers the same period but estimates what consumptive use would have occurred had there been no wells is contained in rg2007_noq.dwb. This is the so­called “No Pumping” scenario.
The amount of historical consumptive use under each ditch is estimated by StateCU. Specifically the consumptive use from surface water application (Surface Water Farm Diversion to CU) and from groundwater application (Groundwater Diversion to CU) is reported. Davis Engineering Service, Inc. provided a summary of the Imported Water Offsets. A program called mkrc was used to summarize the amount of historical consumption from surface water and groundwater and compare it to the Imported Water Offsets for those ditches with recharge decrees.
Table 1 shows these results for the four canals with recharge decrees. For each year (column 1), the Imported Water Offset, as reported by Davis Engineering, is listed in column 2. The amount of consumptive use from direct surface irrigation as reported by StateCU is listed in column 3. The amount of groundwater consumptive use of the Imported Water Offset is the difference of columns 2 and 3 and is shown in column 4. The amount of historical groundwater consumptive use estimated by StateCU is shown in column 5. Column 6 is the difference between column 5 and 4, and shows the amount of historical groundwater consumptive use in excess of the Imported Water Offsets. Column 7 shows the ratio of the Imported Water Offset and the historical groundwater consumptive use (column 4 divided by column 5).
The ratio is the key result from this calculation. Groundwater consumptive use is basically the difference between total groundwater pumping (Groundwater Diversion in StateCU) and return flow (Non­Consumed in StateCU). In order to adjust the groundwater consumptive use to match the Imported Water Offset, multiplying all three of these quantities by the ratio will match the groundwater consumption to the Imported Water Offset while maintaining the correct relationship between total pumping and return flow.
The program mkrc creates a file ratio.dat which reports the ratio needed to match groundwater consumptive use to the imported water offsets for each of the ditches with recharge decrees. The program mkrcdwb then reads this table as well as the historical consumptive use budget file rg2007.dwb and the no pumping consumptive use budget file rg2007_noq.dwb and produces a new consumptive use budget file called rg2007_rc.dwb. In rg2007_rc.dwb, the historical ditch water budgets for the ditches with recharge decrees are adjusted by multiplying the groundwater components by the appropriate ratio. This scales the annual and monthly pumping and recharge numbers such that they match the Imported Water Offsets. For those ditches that do not have recharge decrees, the rg2007_rc.dwb file contains the no pumping budgets from rg2007_noq.dwb. The rg2007_rc.dwb budget file contains ditch budgets where groundwater pumping under every ditch is reduced to the amount of the Imported Water Offset, which is zero in the absence of a recharge decree.
StatePP is then used to generate model input files using the historical ditch budget file rg2007.dwb which is called H5P005 and using rg2007_rc.dwb which is called H5P005­87. The output from StatePP is a set of files consisting of an M&I well pumping file (.mi), agricultural well pumping file (.wel), precipitation recharge file (.ppt), irrigation return flow file (.irr), canal leakage file (.can) and rim recharge (.rim), as well as native (.ets) and subirrigation (.sub1, .sub2 and .sub3) evapotranspiration files. These files cover the period 1988­2005 using monthly stresses.
The H5P005­87 files represent a situation where the impact of all groundwater pumping in the model domain would be evaluated. In order to isolate just the pumping in Subdistrict No. 1, the program mksub is used to generate a new set of output files called H5P005a. How the mksub program is run is shown in the file Mksub. The mksub program switches between areas inside Subdistrict No. 1 and outside Subdistrict #1 on a model cell by cell basis so that the H5P005a data contains the H5P005­87 (impact) results inside Subdistrict No. 1 and H5P005 (historical) results outside Subdistrict No. 1. The impact run for Subdistrict No. 1 is therefore performed using the H5P005a data set, while the historical run is performed using the H5P005 data set.
The reason for this multi­step procedure is that Subdistrict No. 1 does not line up with the ditch service areas. By generating an impact data set for the entire model domain, the mksub program can then select the appropriate data for just Subdistrict No. 1.
The mksub program also has a mode where the subdistrict analysis can be done in a response function mode. The ­u flag instructs the mksub program to use the impact data (in this instance H5P005­87) only during the first year. For all years after the first year, the stresses match the historical data. This allows the impact analysis to isolate the effects associated with a particular year. The ­y flag on the mksub program allows the user to select the order of the years. So, for example, using the command line parameters ­y 1997­2005,1988­1996 will instruct mksub to produce an output file where the historical years 1988­2005 are output in the order 1997­2005 followed by 1988­1996.
Input data sets for a response function analysis starting with each year from 1988 to 2005 and cycling through the historical sequence of years 1988 to 2005 was generated using the instructions in Mkurf. The input data for the historical simulation for each year was named H5P005_YY where YY represents the last two digits of the year. The input data for the impact simulation for each year was named H5P005aYY. Numerical experiments with these simulations showed that response functions so derived introduced some dependency on the exact sequence of years that followed the year being analyzed. This is inappropriate because when using the response function to determine the impacts on streams from a particular year, it is unlikely that the following years will occur in exactly the same historical sequence.
In order to avoid this problem, the response functions were generated using average monthly conditions. The Average Monthly simulation is a simulation where stresses for each calendar month is averaged. These stresses represent what each month typically looks like, and captures the seasonal variations throughout the year. The mkurf program was therefore used to generate response function input data sets that consist of the historical and impact inputs for each of the years 1988­2005, followed by average monthly inputs for each year following the first year. Specifically the H5P005=YY data sets represent the historical data for each year from 1988 to 2005 as the first year in the simulation, followed by 99 years of average monthly data. Similarly, the H5P005AYY data sets represent the impact data set for these years, followed by 99 years of average monthly data.
Model Simulations
Thirty six simulations were generated using the Model, eighteen for historical and eighteen for impact conditions. The historical simulations were named H5A00P12=YYX where YY represents the last two digits for the year. For each simulation the starting heads for that calendar year was extracted from the transient calibration simulation. The simulation was then run for 100 years, where the first year represented the specific historical year and the next 99 years represented monthly average conditions.
The impact simulations were named H5A00P12AYYX. The first year represented the specific year but using the pumping levels appropriate for the recharge decrees. The next 99 years represented monthly average conditions.
The Model outputs consist of four main files. The text output produced by MODFLOW is the .out file and contains information about the simulation such as input files read, calculations, volumetric budgets and the like. A detailed budget is saved using the budget package in the .sbb file. This is a binary file in HYDMOD format which contains a detailed budget for every time step in the simulation for subsequent analysis using the mkbgt program. The stream flows for every stream segment in the model and water level observations at selected well locations are stored in the .sfi file using the HYDMOD package. This file is subsequently analyzed using the mksum program to generate detailed stream gain and loss analysis. Heads throughout the domain at selected times are stored in the .head files.
The simulations require 6­8 hours of computer time each.
Response Function Calculation
The water budget calculated by the Model is summarized using two programs. The mkbgt program is used to analyze all components of the water budget using output saved by MODFLOW in the .sbb file. It produces summary tables of budget terms such as well pumping, recharge, evapotranspiration, stream flows, etc. on an annual basis for the domain as a whole, as well as for geographic regions. Alternatively, when presented with two model simulations, the mkbgt program will report the differences in the budget terms between the model simulations. Since for this application the interest is in the differences in the inputs and output of the model between the historical and impact simulations, the mkbgt program was primarily employed in this mode.
The mksum program operates similarly to the mkbgt program, but analyzes stream flows. The program reads detailed stream flow information from the .sfi files and produces a summary of the inflows, outflows, diversions and gains and losses to the streams. Like mkbgt, the mksum program will report the difference in these terms when presented with two simulations.
The mkbgt and mksum programs for the simulations listed above are run using the program MkurfbgtX. The output is summarized in data sets named P12AyyX­bgt and P12AyyX­str. The .htm files are tables in HTML format that can be viewed using a web browser or spreadsheet program. In addition, detailed monthly values are also saved in DBF format which can be accessed using a spreadsheet or database program.
In the application to Subdistrict #1, the mksum was specifically run with the ­x flag. This flag causes the program to summarize stream depletions by specific reaches of interest for purposes of administration. Specifically, on the Rio Grande, the stream depletions are reported for the reach from Del Norte to the Excelsior Ditch headgate, from the Excelsior Ditch to the Chicago Ditch headgate, and from the Chicago Ditch headgate to the State Line.
For smaller streams in the Closed Basin, stream depletions are summarized from the edge of the model to the last diversion. This subdivision of the stream is rather important. Since the Model is a physical flow model, and not a water rights model, the Model cannot increase historical diversions to simulate how stream gains would be put to beneficial use in accordance with the priority system. By limiting the the impact calculation to only those gains and losses that occur upstream of the last water right, the output more accurately estimates depletions that may affect water rights.
Discussion of Response Functions
In order to evaluate the appropriateness of the response functions as well as ascertain the magnitude of the stream depletions, a model simulation was created similar to those used to determine the response functions described above. The paired runs consisted of the calibration simulation from 1970 to 2005 and an impact simulation which applied the Subdistrict #1 impact stresses for all years from 1970 to 2005. By comparing the predicted stream flows in these simulations the cumulative impact of groundwater pumping from the area covered by Subdistrict #1 can be assessed.
Table 2 shows the computed stream depletions as a result of the groundwater pumping in Subdistrict #1 as an annual average for the last ten years of this model simulation. Using 50 acre­feet of average annual depletion as a lower limit for reporting, it was determined that response functions for Subdistrict #1 impacts are appropriate for each of three streams: the Rio Grande, the Conejos River and La Jara Creek.
The Rio Grande was divided into three administrative reaches based on discussions with the State Engineer's Office. The first reach is from Del Norte to the headgate of the Excelsior Ditch. The second reach is from the Excelsior Ditch to the Chicago Ditch. The third reach is from the Chicago Ditch to the State Line and includes the Norton Drain. A response function was generated for each of these three reaches.
For the Conejos River, a single response function was generated for the Conejos River proper, the Rio San Antonio and McIntyre Spring. The response function represents the combined impact to these three sources.
The La Jara Creek response function represents only La Jara Creek.
Table 3 shows the computed Net Groundwater Consumptive Use from the 1970­2005 simulation as well as the stream depletions computed by the model for the five stream reaches for which response functions were calculated. The Net Groundwater Consumptive Use was calculated as the change in groundwater pumping minus the change in recharge in the model simulations. Here the change refers to the difference between the impact and historical simulations.
The stream depletions shown in Table 3 are the cumulative stream depletion for the period 1970­2005. Therefore, these values can be used to test the predictive ability of the response functions.
Table 1A: Rio Grande Canal (200812)
Year
Imported Water
Offsets
(acre-feet)
(1)
(2)
Groundwater
Surface Water
Groundwater
Consumptive Use of
Consumptive Use
Consumptive Use
Imported Water
in StateCU
in StateCU
Offsets (2)-(3)
(acre-feet)
(acre-feet)
(acre-feet)
(3)
(4)
(5)
Excess
Groundwater
Consumptive
Use (5)-(4)
(acre-feet)
Groundwater
Consumptive
Use Ratio (4)/(5)
(6)
(7)
1970
1971
177757
98178
66926
38183
110831
59995
59513
65661
-51318
5666
1.862
0.914
1972
1973
95514
177992
34902
64680
60612
113312
88861
45557
28249
-67755
0.682
2.487
1974
1975
1976
62937
165670
151512
20147
47042
33162
42790
118628
118350
104919
49408
79507
62129
-69220
-38843
0.408
2.401
1.489
1977
1978
48425
74504
8590
13811
39835
60693
110370
68445
70535
7752
0.361
0.887
1979
1980
149812
144971
29010
22412
120802
122559
109089
112794
-11713
-9765
1.107
1.087
1981
1982
88284
174928
12373
18121
75911
156807
110452
102349
34541
-54458
0.687
1.532
1983
1984
170117
196901
18620
20178
151497
176723
107748
120044
-43749
-56679
1.406
1.472
1985
1986
181909
223503
19060
21844
162849
201659
112552
106880
-50297
-94779
1.447
1.887
1987
1988
138492
106927
16624
12385
121868
94542
121494
119267
-374
24725
1.003
0.793
1989
1990
95977
126794
10728
10079
85249
116715
120129
105917
34880
-10798
0.710
1.102
1991
1992
152339
128809
11450
11683
140889
117126
108828
107986
-32061
-9140
1.295
1.085
1993
1994
1995
184171
141440
225230
13821
9178
15485
170350
132262
209745
109742
126600
107533
-60608
-5662
-102212
1.552
1.045
1.951
1996
1997
90750
179139
6252
11909
84498
167230
128607
125851
44109
-41379
0.657
1.329
1998
1999
141562
215692
8587
12320
132975
203372
140920
112437
7945
-90935
0.944
1.809
2000
2001
77480
155741
5122
10759
72358
144982
148936
134618
76578
-10364
0.486
1.077
2002
2003
18152
51556
1248
4122
16904
47434
165266
134119
148362
86685
0.102
0.354
2004
2005
110660
149727
6687
10171
103973
139556
122634
131807
18661
-7749
0.848
1.059
135377
18824
116552
109079
-7473
1.148
1970-2005
Average
Table 1B: Farmers Union Canal (200631)
Year
Imported Water
Offsets
(acre-feet)
(1)
(2)
Groundwater
Surface Water
Groundwater
Consumptive Use of
Consumptive Use
Consumptive Use
Imported Water
in StateCU
in StateCU
Offsets (2)-(3)
(acre-feet)
(acre-feet)
(acre-feet)
(3)
(4)
(5)
Excess
Groundwater
Consumptive
Use (5)-(4)
(acre-feet)
Groundwater
Consumptive
Use Ratio (4)/(5)
(6)
(7)
1970
24539
24365
174
37662
37488
0.005
1971
1972
9156
11406
16936
8949
0
2457
34574
48933
34574
46476
0.000
0.050
1973
1974
55840
3828
27133
9033
28707
0
31994
52860
3287
52860
0.897
0.000
1975
1976
55838
31803
24386
11929
31452
19874
38556
47324
7104
27450
0.816
0.420
1977
1978
5782
23155
732
3678
5050
19477
62110
49336
57060
29859
0.081
0.395
1979
1980
58069
47897
8151
7671
49918
40226
55084
56101
5166
15875
0.906
0.717
1981
7859
1630
6229
64887
58658
0.096
1982
1983
31774
47665
2441
2759
29333
44906
59426
66723
30093
21817
0.494
0.673
1984
1985
40172
66431
2288
2832
37884
63599
76721
68225
38837
4626
0.494
0.932
1986
1987
48682
34166
2586
2504
46096
31662
65328
72611
19232
40949
0.706
0.436
1988
1989
4725
11127
525
1340
4200
9787
70128
75234
65928
65447
0.060
0.130
1990
1991
25461
31523
1316
1497
24145
30026
63587
68305
39442
38279
0.380
0.440
1992
1993
21901
50125
1043
2106
20858
48019
57381
57195
36523
9176
0.364
0.840
1994
1995
32104
54853
1797
2214
30307
52639
72447
61458
42140
8819
0.418
0.857
1996
1997
1998
10334
60325
23383
1057
2601
788
9277
57724
22595
77424
54966
72623
68147
-2758
50028
0.120
1.050
0.311
1999
2000
61857
11432
2245
732
59612
10700
63913
81174
4301
70474
0.933
0.132
2001
2002
44591
1283
1782
2
42809
1281
69291
83509
26482
82228
0.618
0.015
2003
2004
4572
16361
585
837
3987
15524
78233
73655
74246
58131
0.051
0.211
2005
34096
1760
32336
77236
44900
0.419
30670
5118
25913
62395
36482
0.430
1970-2005
Average
Table 1C: Prairie Ditch (200798)
Year
Imported Water
Offsets
(acre-feet)
(1)
(2)
Groundwater
Surface Water
Groundwater
Consumptive Use of
Consumptive Use
Consumptive Use
Imported Water
in StateCU
in StateCU
Offsets (2)-(3)
(acre-feet)
(acre-feet)
(acre-feet)
(3)
(4)
(5)
Excess
Groundwater
Consumptive
Use (5)-(4)
(acre-feet)
Groundwater
Consumptive
Use Ratio (4)/(5)
(6)
(7)
1970
1971
13474
6969
7284
3330
6190
3639
17169
16804
10979
13165
0.361
0.217
1972
1973
10541
16110
4077
5530
6464
10580
19829
17426
13365
6846
0.326
0.607
1974
1975
3647
22434
987
3993
2660
18441
23064
19075
20404
634
0.115
0.967
1976
1977
13802
1004
1432
71
12370
933
21140
24613
8770
23680
0.585
0.038
1978
1979
9868
22694
458
649
9410
22045
21024
23188
11614
1143
0.448
0.951
1980
1981
18150
5771
777
288
17373
5483
22738
23741
5365
18258
0.764
0.231
1982
1983
19101
18844
796
630
18305
18214
22018
24312
3713
6098
0.831
0.749
1984
1985
21715
24256
1077
1227
20638
23029
27819
24892
7181
1863
0.742
0.925
1986
1987
1988
19382
10782
5178
1163
773
388
18219
10009
4790
23869
26322
25223
5650
16313
20433
0.763
0.380
0.190
1989
1990
11251
13735
826
841
10425
12894
27144
23089
16719
10195
0.384
0.558
1991
1992
15928
13473
831
1060
15097
12413
24468
20982
9371
8569
0.617
0.592
1993
1994
18447
15180
1286
969
17161
14211
20654
25775
3493
11564
0.831
0.551
1995
1996
27291
8027
1574
559
25717
7468
21824
27504
-3893
20036
1.178
0.272
1997
1998
23614
14426
1645
1109
21969
13317
20551
25762
-1418
12445
1.069
0.517
1999
2000
26513
11020
1729
757
24784
10263
22543
28694
-2241
18431
1.099
0.358
2001
2002
18686
1806
1186
111
17500
1695
24624
29567
7124
27872
0.711
0.057
2003
2004
2005
4515
10505
16303
459
1065
1354
4056
9440
14949
27717
26134
27476
23661
16694
12527
0.146
0.361
0.544
14290
1453
12838
23577
10740
0.557
1970-2005
Average
Table 1D: San Luis Valley Canal (200829)
Year
Imported Water
Offsets
(acre-feet)
(1)
(2)
Groundwater
Surface Water
Groundwater
Consumptive Use of
Consumptive Use
Consumptive Use
Imported Water
in StateCU
in StateCU
Offsets (2)-(3)
(acre-feet)
(acre-feet)
(acre-feet)
(3)
(4)
(5)
Excess
Groundwater
Consumptive
Use (5)-(4)
(acre-feet)
Groundwater
Consumptive
Use Ratio (4)/(5)
(6)
(7)
1970
1971
18604
7084
8671
3055
9933
4029
11215
12120
1282
8091
0.886
0.332
1972
1973
9830
20183
4234
8353
5596
11830
14821
12848
9225
1018
0.378
0.921
1974
1975
5416
28616
2150
10804
3266
17812
18335
13123
15069
-4689
0.178
1.357
1976
1977
15783
680
5246
200
10537
480
17933
24840
7396
24360
0.588
0.019
1978
1979
10374
26917
2495
5963
7879
20954
21301
21392
13422
438
0.370
0.980
1980
1981
23015
4472
4278
722
18737
3750
24056
26379
5319
22629
0.779
0.142
1982
1983
1984
18221
20714
18597
2896
3189
2952
15325
17525
15645
23610
25543
29152
8285
8018
13507
0.649
0.686
0.537
1985
1986
21060
27313
3429
4500
17631
22813
26330
24847
8699
2034
0.670
0.918
1987
1988
13515
8481
2253
1288
11262
7193
28503
27792
17241
20599
0.395
0.259
1989
1990
10865
11957
1852
1935
9013
10022
29736
25652
20723
15630
0.303
0.391
1991
1992
22990
14087
3082
2218
19908
11869
26770
24277
6862
12408
0.744
0.489
1993
1994
24016
17432
3538
2627
20478
14805
22332
27960
1854
13155
0.917
0.530
1995
1996
33482
8962
3941
806
29541
8156
23242
29866
-6299
21710
1.271
0.273
1997
1998
29010
18016
3791
2682
25219
15334
23443
28396
-1776
13062
1.076
0.540
1999
2000
29920
14557
3877
1475
26043
13082
24548
31869
-1495
18787
1.061
0.410
2001
2002
2003
25287
0
3282
3226
0
527
22061
0
2755
27730
33233
31300
5669
33233
28545
0.796
0.000
0.088
2004
2005
12229
20166
1965
3240
10264
16926
29005
30485
18741
13559
0.354
0.555
16532
3263
13269
24277
11009
0.579
1970-2005
Average
Table 1E: All Four Canals with Recharge Decrees
Year
Imported Water
Offsets
(acre-feet)
(1)
(2)
Groundwater
Surface Water
Groundwater
Consumptive Use of
Consumptive Use
Consumptive Use
Imported Water
in StateCU
in StateCU
Offsets (2)-(3)
(acre-feet)
(acre-feet)
(acre-feet)
(3)
(4)
(5)
Excess
Groundwater
Consumptive
Use (5)-(4)
(acre-feet)
Groundwater
Consumptive
Use Ratio (4)/(5)
(6)
(7)
1970
234374
107246
127128
125559
-1569
1.012
1971
1972
121387
127290
61504
52162
59883
75128
129159
172444
69276
97316
0.464
0.436
1973
1974
1975
270125
75828
272559
105696
32317
86225
164429
43511
186334
107825
199178
120162
-56604
155667
-66172
1.525
0.218
1.551
1976
1977
212901
55892
51769
9593
161132
46299
165904
221933
4772
175634
0.971
0.209
1978
1979
117901
257492
20442
43773
97459
213719
160106
208753
62647
-4966
0.609
1.024
1980
1981
234034
106385
35138
15013
198896
91372
215689
225459
16793
134087
0.922
0.405
1982
1983
244024
257340
24254
25198
219770
232142
207403
224326
-12367
-7816
1.060
1.035
1984
1985
277385
293656
26495
26548
250890
267108
253736
231999
2846
-35109
0.989
1.151
1986
1987
318879
196956
30093
22154
288786
174802
220924
248930
-67862
74128
1.307
0.702
1988
1989
125312
129221
14586
14746
110726
114475
242410
252243
131684
137768
0.457
0.454
1990
1991
177948
222780
14171
16860
163777
205920
218245
228371
54468
22451
0.750
0.902
1992
1993
1994
178271
276759
206157
16004
20751
14571
162267
256008
191586
210626
209923
252782
48359
-46085
61196
0.770
1.220
0.758
1995
1996
340856
118072
23214
8674
317642
109398
214057
263401
-103585
154003
1.484
0.415
1997
1998
292087
197387
19946
13166
272141
184221
224811
267701
-47330
83480
1.211
0.688
1999
2000
333982
114490
20171
8086
313811
106404
223441
290673
-90370
184269
1.404
0.366
2001
2002
244305
21241
16953
1361
227352
19880
256263
311575
28911
291695
0.887
0.064
2003
2004
63925
149756
5693
10554
58232
139202
271369
251428
213137
112226
0.215
0.554
2005
1970-2005
Average
220291
16525
203766
267004
63238
0.763
196868
28657
168211
219328
51117
0.804
Table 2: Subdistrict #1 Computed Stream Depletions
Stream
Rio Grande
LaJara Creek
McIntyre Spring
Werner Arroyo
Alamosa River
Conejos River
Saguache Creek
Norton Drain
San Luis Creek
Rio San Antonio
Sand Creek
Trinchera Creek
Deadman Creek
Big Spring Creek
Rito Alto
Little Spring Creek
Crestone Creek
Willow Creek
SanIsabel Creek
Cottonwood Creek
SangreDeCristo Creek
Culebra Creek
Kerber Creek
Spanish Creek
Cotton Creek
Zapata Creek
Costilla Creek
WildCherry Creek
Major Creek
Ute Creek
Medano Creek
Carnero Creek
Garner Creek
LaGarita Creek
Average Depletions
1996-2005 (af)
5599
136
108
48
44
41
36
24
21
11
10
7
7
5
2
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 3: Modeled Net Groundwater Consumptive Use and Stream Depletions
Year
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
Modeled Stream Depletions (acre-feet)
Modeled Net
Rio Grande
Conejos River
Groundwater
Rio Grande Rio Grande
Chicago
to
Rio
San Antonio
Consumptive Use Del Norte to Excelsior to
State
Line
and
(acre-feet)
Excelsior
Chicago
and Norton Drain
McIntyre Spring
71127
571
96
0
11
76221
1075
240
4
24
95402
1501
289
21
44
32567
1670
275
19
45
117499
1944
366
0
67
55757
2020
318
42
62
70622
2136
338
9
63
142784
2442
412
-12
84
97373
2781
575
79
107
42201
2842
536
41
99
67340
2857
503
26
96
138137
3184
592
42
116
77565
3331
699
38
109
72875
3213
662
24
105
85497
3316
645
34
112
52320
3339
627
40
107
62383
3153
578
24
94
113999
3214
644
24
92
147975
3341
699
33
110
148981
3600
777
34
134
102130
3691
866
52
135
90647
3767
794
35
139
87331
3855
798
24
135
49299
3775
776
38
125
104524
3808
728
26
134
59254
3648
682
8
112
156575
3748
683
25
135
33514
3775
754
86
125
120623
3699
671
17
127
-53610
2627
665
73
113
233148
3109
603
0
121
71835
3777
692
57
138
347807
4334
700
-45
130
259224
6663
991
62
195
149038
8173
1164
85
258
101464
7809
1153
84
267
La Jara
Creek
7
25
37
50
56
70
71
68
84
92
96
93
112
123
133
143
142
137
125
118
121
129
136
149
145
162
136
146
134
139
103
119
88
120
175
203