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Reports Utah Water Research Laboratory
January 1984
Management of Groundwater Recharge Areas in the Mouth of Weber Canyon
Calvin G. Clyde
Christopher J. Duffy
Edward P. Fisk
Daniel H. Hoggan
David E. Hansen
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Recommended Citation Clyde, Calvin G.; Duffy, Christopher J.; Fisk, Edward P.; Hoggan, Daniel H.; and Hansen, David E., "Management of Groundwater Recharge Areas in the Mouth of Weber Canyon" (1984). Reports. Paper 539. https://digitalcommons.usu.edu/water_rep/539
This Report is brought to you for free and open access by the Utah Water Research Laboratory at DigitalCommons@USU. It has been accepted for inclusion in Reports by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. MANAGEMENT OF GROUNDWATER. RECHARGE AREAS
IN THE MOUTH OF WEBER. CANYON
by
Calvin G. Clyde, Christopher J. Duffy, Edward P. Fisk, Daniel H. Hoggan, and David E. Hansen
HYDRAULICS AND HYDROLOGY SERIES UWRL/H-84/01
Utah Water Research Laboratory Utah State University Logan, Utah 84322
May 1984
ABSTRACT
Proper management of surface and groundwater resources is important for their prolonged and beneficial use. Within the Weber Delta area there has existed a continual decline in the piezometric surface of the deep confined aquifer over the last 40 years. This decline ranges from approximately 20 feet along the eastern shore of the Great Salt Lake to 50 feet in the vicinity of Hill Air Force Base. Declines in the piezometric surface are undesirable because of increased we 11 installation costs, in creased pumping costs, decreased aquifer storage, increased risk of salt water intrusion, and the possibility of land subsidence. Declines in the piezometric surface can be prevented or reduced by utilizing artificial groundwater recharge.
The purpose of this study was to develop and operate a basin groundwater model with stochastic recharge inputs to determine the feasibility of utilizing available Weber River water for the improvement of the groundwater availability. This was accom plished by preparing auxiliary computer models which generated statistically similar river flows from which river water rights were subtracted. The feasibility of utilizing this type of recharge input was examined by comparing the economic benefit gained by reducing areawide pumping lifts through artificial recharge with the costs of the recharge operations. Institutions for implementing a recharge program were examined.
Through· this process a greater understanding of the geo hydrologic conditions of the area was obtained. piezomet r ic surface contour maps, geologic profiles, calibrated values for geologic and hydrologic variables, as well as system response to change were quantified.
iii ACKNOWLEDGMENTS
Funding of this proj ect by the Utah Water Research Labora tory is gratefully recognized. The writers appreciate the ready cooperation and assistance given by federal, state, and county agencies, the Weber Basin Water Conservancy District, and private individuals.
iv TABLE OF CONTENTS
Page
INTRODUCTION 1
Problem Description and Opportunity 1 Need for Artificial Recharge . 1 Past Recharge Studies 3 Previous Studies and Data Sources 5
GEOHYDROLOGIC DESCRIPTION 7
Location 7 Phys iography 7 Geology . 9
Geologic Profiles 9 Underlying Bedrock Complex 9 Older Valley Fill . 10 Delta Aquifer 10 Lake Bonneville Group 18 Recent Sediments 18
Groundwater Hydrology 18
Recharge 18
Surface Water Hydrology 19
Storage 20 Discharge 21 Delta Aquifer Water Levels 21 Regimen of Flow 25 Groundwater Quality 25
ARTIFICIAL RECHARGE 27
Overview 27
Water Spreading 28 Recharge Basins 28 Inj ect ion We 11s 28
Field Conditions at the Weber Delta Site 29 Discharge Hydrographs and Water Availability 30 Proposed Operation for Artificial Recharge 31
v TABLE OF CONTENTS (Continued)
Page·
APPLICATION OF COMPUTER MODELS 35
Groundwater Model 35
Conceptualization 36 Finite Element Grid 38 Computer Input . 40 Limitations and Neglected Features 47
Statistical Models 48
Annual Time Series Generation 49 Monthly Time Series Generation 52
MODEL RESULTS 55
Statistical Models 55
Yearly Flow Generation 55 Monthly Flow Generation 55 Available Flows 57
Groundwater Model 57
Steady State Calibration 58 Transient Calibration 60 Verification 64 Sensitivity Analysis . 67 Recharge Simulation Runs 80
INSTITUTIONAL AND ECONOMIC CONSIDERATIONS 91
Water Resources Management 91 Water Rights 91 Institutional Arrangements for Groundwater Recharge System 92 Prompt Action to Obtain Land . 93
Recharge Pit Construction and Operation 93 Recharge Operation 93 Other Economic Benefits . 94
SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS 95
Summary . 95 Cone lusions Recommendations 95
SELECTED BIBLIOGRAPHY . 96 vi LIST OF FIGURES
Figure Page
1. Change in piezometric surface for the Delta Aquifer between 1937 and 1980 2
2. Locations of the recharge area, geologic profiles, Weber Delta, and the Weber Delta subdistrict 8
3. Geologic profile NW-E, Weber Delta Subdistrict, East Shore area of Great Salt Lake, Utah 11
4. Geologic profile W-E, Weber Delta Subdistrict, East Shore area of Great Salt Lake, Utah 13
5. Geologic profile SW-E, Weber Delta Subdistrict, East Shore area of Great Salt Lake, Utah 15
6. Yearly discharges for the Weber River at Gateway 20
7. 1937 piezometric contour map for the Delta Aquifer 22
8. 1945 piezometric contour map for the Delta Aquifer 22
9. 1955 piezometric contour map for the Delta Aquifer 22
10. 1964 piezometric contour map for the Delta Aquifer 22
11. 1970 piezometric contour map for the Delta Aquifer 23
12. 1974 piezometric contour map for the Delta Aquifer 23
13. 1980 piezometric contour map for the Delta Aquifer 23
14. 4300-ft piezometric contour line plotted at advancing time intervals 24
vii LIST OF FIGURES (Continued)
Figure Page
15. 4280-ft piezometric contour line plotted at advanc~ng time intervals . 24
16. Average monthly flows, Weber River at Gateway, 10136500 32
17. Flow duration curves for the Weber River at Gateway, 1921-1957 and 1958-1978 32
18. Flow duration curves for the Weber River near Plain City 33
19. Average monthly flows for the Weber River near Plain City, 10141000 33
20. Computer model boundaries and simplified land use patterns 37
21. Contours on the top of the main Delta Aquifer 39
22. Contours on the effective bottom of the Delta Aquifer 40
,23. Effective thickness of the Delta Aquifer 41
24. Nodal numbering system for the finite element grid . 42
25. Element numbering system for the finite element grid 42
26. Distribution for mountain front recharge showing percent of average flow per foot 44
27. Project area pumping withdrawal as percentage of East Shore are totals as a function of time. 45
28. Historical pumping rates used for the Weber Delta area 47
29. Municipal and industrial, irrigation, and. military pumping reg10ns . 48
30. Double mass flow plot for the Weber River at Gateway and the Weber River at Oakley, Utah 50
31. Comparisons between spectral density functions for the Weber River 51
32. Calibrated permeability distribution in ft/yr 61
viii LIST OF FIGURES (Continued)
Figure Page
33. Calibrated K'/B' distribution in l/yr 61
34. Distribution of calibrated specific yield and storativity coefficients . 61
35. Calibrated and assumed 1937 contour lines 62
36. Regression of well B-5-l-36bbb (node 10) versus well B-4-l-30bba (node 95) 63
37. Comparisons between unaltered and regressed well B-5-1-36bbb (node 10) and mountain front recharge 64
38. 1940-1970 simulated vs. historical hydrographs for well B-5-l-37bbb (node 10) 65
39. 1940-1970 simulated vs. historical hydrographs for well B-5-1-33cda (node 62) 65
40. 1940-1970 simulated vs. historical hydrographs for well B-4-l-30bba (node 95) 65
41. 1940-1970 simulated vs. historical hydrographs for well B-4-2-12bcd (node 97) . 65
42. 1940-1970 simulated vs. historical hydrographs for well B-6-1-30cca (node 104) 65
43. 1940-1970 simulated vs. historical hydrographs for well B-5-2-33ddc (node 129) 65
44. 1940-1970 simulated vs. historical hydrographs for well B-5-2-4ddc (node 133) 66
45. 1940-1970 simulated vs. historical hydrographs for well B-4-2-20ada (node 138) 66
46. 1940-1970 simulated vs. historical hydrographs for well B-4-2-8dcc (node 139) 66
47. 1940-1970 simulated vs. historical hydrographs for well B-5-3-13ddc (node 152) 66
48. 1940-1970 simulated vs. historical hydrographs for well B-5-3-15dda (node 161) 66
49. Nodes used for comparison of simulated vs. historical well response during calibration and verification 67 ix LIST OF FIGURES (Continued)
Figure Page
50. Comparison between assumed and simulated piezometric contours for 1940 68
51. Comparison between assumed and simulated piezometric contours for 1945 69
52. Comparison between assumed and simulated piezometric contours for 1955 70
53. Comparison between assumed and simulated piezometric contours for 1964 71
54. Comparison between assumed and simulated piezometric contours for 1970 72
55. 1970-1981 simulated vs. historical hydrographs for well B-5-l-33baa (node 63) . 73
56. 1970-1981 simulated vs. historical hydrographs for well B-4-l-l6bdd (node 72) . 73
57. 1970-1981 simulated vs. historical hydrographs for well B-4-1-7baa (node 86) 74
58. 1970-1981 simulated vs. historical hydrographs for well B-5-l-18abb (node 90) . 74
59. 1970-1981 simulated vs. historical hydrographs for well B-4-1-30bba (node 95) . 75
60. 1970-1981 simulated vs. historical hydrographs for well B-4-2-20aaa (node 115) 75
61. 1970-1981 simulated vs. historical hydrographs for well B-5-2-33ddc (node 129) 76
62. 1970-1981 simulated vs. historical hydrographs for well B-5-2-l6dcd (node 131) 76
63. 1970-1981 simulated vs. historical hydrographs for well B-4-2-20ada (node 138) 77
64. 1970-1981 simulated vs. historical hydrographs for well B-5-3-12add (node 153) 77
65. 1970-1981 simulated vs. historical hydrographs for well B-5-3-15dda (node 161) 78
66. Comparison between assumed and simulated piezometric contours for 1974 78
x LIST OF FIGURES (Continued)
Figure Page
67. Comparison between assumed and simulated piezometric contours for 1980 79
68. Central nodes and surrounding elements used in the sensitivity analysis. 19
69. Sensitivity plots for node 86 81
70. Sensitivity plots for node 90 82
71. Sensitivity plots for node 131 83
72. Recharge hydrograph comparisons for node 63 with a maximum recharge rate of 1350 ac-ft per month . 84
73. Recharge hydrograph comparisons for node 72 with a maximum recharge rate of 1350 ac-ft per mont h . 84
74. Recharge hydrograph comparisons for node 86 with a maximum recharge rate of 1350 ac-ft per month . 85
75. Recharge hydrograph comparisons for node 90 with a maximum recharge rate of 1350 ac-ft per month . 85
76. Recharge hydrograph comparisons for node 129 with a maximum recharge rate of 1350 ac-ft per month . 86
77. Recharge hydrograph compar.isons for node 131 with a maximum recharge rate of 1350 ac-ft per month . 86
78. Recharge hydrograph comparisons for node 86 utilizing all available water at Gateway and plain City 88
79. Recharge hydrograph comparisons for node 90 utilizing all available water at Gateway and Plain City 89
80. Recharge hydrograph comparisons for node 153 utilizing all available water at Gateway and Plain City 89
xi LIST OF TABLES
Table Page
1. Modeling capabilities of AQUIFEM-l 37
2. Aquifer properties for the main member of the Delta Aquifer and sources of information 43
3. Project withdrawal percentage of East Shore area totals 45
4. Summary of well discharge history for East Shore area, Utah (ac-ft) . 46
5. Calculated spectral densities for the Weber River for the period 1921-1977 51
6. Spectral density for the Weber River at Gateway using FFT.FOR . 51
7. Difference between monthly means and lagged monthly means 52
8. Comparison between the theoretical and generated means, standard deviations and sk~ws for GENSPEC.FOR . 55
9. Comparison between generated and observed monthly statistics (mean/standard deviation) 56
10. Correlation between January through December Weber River flows at Gateway 56
11. Average wasted Weber River flows into the Great Salt Lake (1956-1977) . 58
12. Monthly estimates for utilized Weber River water rights (ac-ft) 59
13. Maximum available water at Gateway and Plain City (ac-ft/mo) . 87
14. Hypothetical quantities and distribution of recharge for extreme recharge conditions 87
15. Cost estimate of recharge systems 94 xii INTRODUCTION
Problem Description reservo1r the quant ity of water stored and Opportunity and the amount available for use is reduced by losses from the system. In Water availability and economics surface reservoirs these losses result are of primary concern when contemplat from infiltration into the ground and ing further development of any area. from evaporation. The loss due to Suffic ient wa ter suppl ies have been evaporation may be a significant quan available in the past to accommodate the tity of water. needs of the growing population along tQe Wasatch Front. The water easiest to System losses 1n groundwater obtain was utilized first. As these reservoirs can consist of water moving easy sources became fully appropriated, out of the system in any direction and Or as expansion increased into areas not 1n shallow aqui fers by evapotranspira supplied by surface water, groundwater tion. In groundwater systems water became an important alternate supply. movement occurs very slowly compared to surface water movement. This allows Weber and Davis Counties, Utah, groundwater systems to be used as have typically been areas where sub storage reservoirs wherein ev'aporation surface water has been utilized to is usually negligible. augment the surface water supply. During the early to mid 1900s the major Artificial groundwater recharge use of groundwater was for agriculture. could be an important means, not only Within the last 20 years industrial and to stop, but also to reverse the long municipal water uses have greatly term downward t rend in groundwater increased. In some locations, including pumping levels. Artificially intro the Weber Delta subdistric t of the East ducing water into the ground can be Shore area, this extraction has con accomplished by surface spreading, tinued at a higher rate than the natural ponding, or injection into wells. The recharge to the area, and has resulted area considered herein appears to be 1n a net depletion in groundwater ideally suited to recharge through storage. In the Weber Delta region, ponding due to the extremely porous overdraft of the groundwater supply not alluvial materials found near the only has increased pumping lifts and mountain front. Beginning a short hence operational costs, but could also distance west of the mountain front at init iate land subsidence. Moreover, the mouth of Weber Canyon, a confined Some potential exists for salt water aquifer system extends westward through intrusion from the Great Salt Lake. out the region. Many water users pump from this confined groundwater Artificial groundwater recharge is system and would benefit from the a technique of introducing water into a decrease in pumping lifts caused by groundwater system to enhance ground artificial recharge. water quality, reduce pumping lifts, store water, or salvage storm runoff or Need for Artificial Recharge waste waters. Groundwater aquifers, just like surface reservoirs, can be Water level records have been used as storage facilities. In any obtained for selected wells in the East
I Shore area starting 1n 1937 and water wells over the 1937-1980 period, a map level contour maps have been prepared was developed to show the areas of major for spec ific years since that time. It drawdown in the principal artesian appears that since the mid-1950s there aquifer. Figure 1 shows the change in has been a gradual trend towards de piezometric surface between 1937 and c! ining groundwater levels. From the 1980 as we 11 as other sal ient features changes which have occurred in selected of the area.
R3W R2W RIW
T5N
T4N
Scale
3 2 o 3 miles bi 2 3 4 5 km
Figure 1. Change in piezometric surface for the Delta Aquifer between 1937 and 1980. Contours are lines of equal change in feet.
2 Since 1940 the groundwater reser continued for approximately 7 years only VOIr in the confined Delta Aquifer a small portion of the applied water system has dec1 ined by more than 50 ft reach ed the c onfi ned aqui fe r s ys t em (15 m) in the vicinity of Hill Air Force through a more pervious zone west of the Base. If allowed to continue, the recharge area. Perhaps the most impor decline will result in increasing energy tant conclusion was that water spreading costs and at the same time will reduce techniques are not universally applic the storage and recovery potential of able along the Wasatch Front, and the groundwater aquifer. This long term ext reme care should be taken to insure downward groundwater trend shows that an that the recharge waters can effectively imbalance between the natural recharge reach the artesian aquifers. and groundwater usage has caused a depletion of aquifer storage. However, The most thorough study of artifi there has been no appreciable change in cial groundwater recharge in Utah was piezometric surface on the outer fringes conducted by the United States Bureau of of the map of Figure 1. If artificial Reclamation (Feth et al. 1966). Exten recharge c oul d revers e t he downward sive drilling, research, and testing trend in water levels, economic benefits were completed in the Weber Delta area would accrue to present and future users near the mouth of Weber Canyon during of this groundwater resource. the early 1950s.
Past Recharge Studies Four recharge experiments were conducted between 1953 and 1958 to test Past art i fi-c ial groundwa ter re the response of the deep artesian Delta charge stud ies c ompl eted wi thin the Aquifer system to artificial recharge. State of Utah are centralized along the Recharge waters were diverted from the highly populated areas of the Wasatch Weber River into an abandoned gravel pit Front. Stud ies have been compl eted In approximately 0.25 mi (0.40 km) west of Ut ah Valley, Sal t Lake Valley, and In the canyon mouth. The first two experi Davis, Weber, and Box Elder Counties. ments diverted an average of 7 cfs/ac (490 l/sec/ha) into the gravel pit The first study for the Salt Lake during February and March of 1953. area was done by A. J. Lazenby (1936). After 3 days from the start of recharge, Two tests were performed within an area an observation well 0.25 mi (0.40 km) of approximately 5 m2 (13 km2 ) located we s t 0 f the r e c h a r g e pit s tar ted along the east side of Salt Lake City. responding to the recharge waters and The general conclusions of these re rose a total of 34 ft (10 m) during the charge tests were that groundwater experiment. Water levels in other wells recharge should be implemented to being monitored from 3 to 6 mi (5 to 10 improve the capacity of groundwater km) west of the recharge pit rose within wi thd rawal and to prevent mining of the a month. groundwater reservoir. The third recharge experiment was Water spreading via canals was conducted from December 1954 to March adopted by the City of Bountiful, 1955. Exceptionally cold weather and Utah, in 1941 (Thomas 1949). The turbid water reduced the effectiveness original intent of the spreading of the test, but the response times and operation was to supply water to an effect s were simi lar to experiments 1 ar t e s ian a qui fer s y stem d uri n g non and 2. irrigation periods so that it might later be reclaimed for use. Unfor The fourth recharge experiment was tunately the spreading sites were not in conducted from November 1957 to February direct hydraulic communication with the 1958. The resul ts showed an average of aquifer. Although the spreading project 3.5 ft (1.1 rn) of increased head within
3 the confined aqui fer system after the that the water is already fully appro groundwa ter mound in the recharge area priated and any recharged water would had dissipated. The u.s. Bureau of have to be purchased, and that a re Reclamation concluded that recharge charge project is not needed. None of water can be infiltrated successfully in the potential problems of decreasing the experiment area and that it does water levels, increased aquifer demands, reach the princ ipal aqui fer as demon land subsidence, or maintenance of water strated by the increase of water levels quality exist in Utah County. 1n observation wells up to 6 miles west of the recharge point (Feth 1966). Hansen (1978) completed a study in Salt Lake County for the Utah Division Land surface infiltration of water of Water Rights under the same legisla 1S feasible for the Weber Delta area due tive mandate. Included in his report to the high vert ic al hyd raul ic conduc are brief reviews of two preV10US tiviti.es at the recharge site. In studies conducted 1n the Salt Lake contrast, conditions at the Bountiful Valley. Four potential recharge sites site were not suitable for surface were chosen and brief feasibility spreading due to low vertical hydraulic analyses were completed on them. conductivities. However, artificial Recommendations made by Hansen were: recharge through inject ion we lIs might be possible at Bountiful if the hori 1- The state should purchase the zontal conductivities prove to be property needed for future artificial adequate. recharge.
The Utah Geological and Mineral 2. Purchased recharge areas could Survey conducted a recharge related be temporarily leased as sand and gravel study in the Mount Olympus Cove area.. of operations where appropriate. With Salt Lake City in the fall of 1974 which proper supervision these areas could be deal t wi th the physical terrain and the so excavated as to become future re factors relating to urban growth and charge pits. also discussed methods whereby runoff water could be introduced into the 3. Exhausted gravel pits not subsurface environment. The study immediately needed for recharge should concluded that artificial groundwater be developed as parks, thus allowing recharge could be introduced through the later convers ion into recharge areas as use of injection wells. needed.
The 1977 State Legislature directed 4. Appropriate sites could b.e the Utah Division of Water Rights to converted into golf courses with evaluate the feasibility and cost of certain low-lying areas utilized for diverting excess and surplus water to recharge as required. increase the recharge to aquifers along the Wasatch Front. Nielsen, Maxwell & 5 . Te s t an d 0 b s e rv a t ion we 11 s Wangsgard compl eted a feasibil ity study should be completed to observe if under the direction of the State Engi the water will enter the proper aquifer neer in which geology, water supply, system. and specific sites in Utah County were considered (Carpenter 1978). Six major 6. The use of the proposed county recharge areas were chosen and a brief wide storm drain and reservoir system as evaluation of each site was documented a possible source of recharge water inc luding discussion of the location, shoul d be stud ied . \Yater sources, required facilities, costs, and other considerations. The The final study for the Utah conclusions reached by the s~udy are Division of Water Rights was completed
4 by Valley Engineering (1978) and in Weber Delta area. Much of the geologic cluded Davis, Weber, and Box Elder research was done by the U.S. Bureau of Counties. Fifteen recharge sites were Reclamation (USBR) during the 1950s. identified, and brief descriptions as to The data taken up to that time were 10 cat ion, 0 wn e r s hip, g eo log y , wa t e r summarized in the U. S. Geological source, water diversion point, existing Survey, Professional Paper 518 (Feth et local we 11s, possibilities of success, a1. 1966). The USBR (1982) g'enerouslY and estimated costs were given. Of all provided old unpublished records and the recharge sites considered, the data pertaining to the study area. one which was chosen as having the most promise of success is the one proposed Another source of information in this investigation near the mouth of titled "Groundwater Conditions in Weber Canyon. Utahl! ~s pub lished by the Utah Depart ment of Natural Resources, Division Previous Studies and of Water Resources (1964-81) and the Data Sources U.S. Geological Survey in the spring of each year. Especially relevant from The most complete report pertaining these report s are the contour maps of to the East Shore area of Weber County groundwater level changes for the East was prepared by the U. S. Geological Shore area. Survey in cooperation with the Utah Department of Natural Resources (Bolke Water well level records extend and Waddell 1972). The report describes back to the mid 1930s, but only a few the area, well construction, aquifer are cont inuous or compl ete. Addit ional discharges, water level fluctuations, water related records have been obtained changes in storage, and chemical qual from U.S. Geological Survey, Water ity. Supply Papers, Utah Basic Data Report • No. 1 (Smith "1961), and from personal Extensive data are available on communications with the U.S. Geological geologic and water conditions in the Survey (Herbert et al. 1982).
5 iti ~rR. -- IBON ,...,c~ -leON Q:, -' Well USBR No. 34, (B-5-1) 20ddd, Bend in section Weber Della No.2, So. Weber No.1
-ISDN
Weber R.
r o "0. C/l !;; o "-..
Well (B-5-\1 26 bbc Bend in section ... --.---
_leON
Weber R. tD ~ --I'""::r"O "0 US S9 - Well (B-5-1136bbb .a.. *Co -'-~---- [ 1>g Gravel Pit i I J
;u~ ~; rT1 0 III .I> (]I ...... ~ 0 '"0 0 0 0 0 0 0 0 0 0 0 '"0 0 0 0 0 0 0 0 ELEVATION IN FEET ABOVE MEAN SEA LEVEL
• ",:~_ ••• :".: "", , •••••• y' -;,'~.;,;;.t.,:;;:,,*,.ol'~~r.,;~~U;-~"""""-';i;'-"''''''-=-7''''''''--- , I
E Wasalch Range .!?'" ------u------~7000 ~ c: Proposed ".. Recharge Area CD'"
.<> i .., .<>1 6000 .<> J .Q ..,1 o a ~I o "'I '", Della Aquifer ~ ;;;:e Ir i c Surface ! ~~~---t--j:~~~~~~;~~;;~~RiIiGi~~MI~~m~~lll 2000 ---...... --..... ----.. ----.- -- --.------l- 1000 ke, Ut ah. E WASATCH c c E 0 RANGE U u ------: ------~------:: ------7000 c c "'C "'C '" C ______~ CD'" CD'" Weber River Valley 0 u 6000 0 u Proposed .Q "'C '" I"- Recharoe Area :::'" '" l 0 (J') .0 oJ , , o CD .Q -'. o .Q I&J Ii> Ii> Ii> en <0 , , 1<)::> .., > CD I&J CD oJ .. I co Ii> 10 .. I&J ;I: ~ , . III'" ~ ~ 5000 Z 'i -; <[ -r~ ~ I&J ::r: ---- loll ---- > 0 CD <[ 4000 ~ I&J 11.1 Wasatch !o.. Fault ~ Zone Z 0 ~ > I&J 3000 oJ !&J 2000 ------~IOOO Utah. and some adjoining areas. It is com away from their apex areas and inter posed mainly of coarse-grained sands and finger with other basin sediments around gravels with thin interfingering layers their peripheries. This 1S evident ly of clay, silt, and sand. Much of it is true of the Delta Aquifer. desc ribed in drillers' logs as "boulders and clay," thus indicating chaotic The uppermost approximately 100 ft conditions of deposition characteristic (30 m) (not stippled in the geologic of mudflows. The Delta Aquifer probably profiles) of the Delta Aquifer are represents a large alluvial fan of mixed particularly more lenticular and are mud flow and braided-streamflow or1g1n finer grained than the main body of the which has coalesced with minor alluvial aquifer below. In the recharge area fans and colluvium of the Wasatch Front. they are separated from the main body by It evidently formed near the beginning a clay stratum. It is believed that of a pluvial stage of the Ple.istocene most of the groundwater of the aqui fer Epoch as increasing precipitation and is transmitted through the main body of runoff dislodged accumul ated alluvial more cont inuous and coarser-grained and glacial sediments of the upper Weber sediments. This uppennost portion of Valley. The coarse-grained sediment s the aquifer probably represents inter that underlie the Delta Aquifer and fingering deposits of an encroaching but which are assumed to be hydraulically widely fluctuating lake interrupting the interconnected with it could be of alluvial fan deposition. PI eistocene or even of upper Tertiary age. Alluvial fans usually make excel lent aquifers', especially those of Although the Delta is the principal braided-stream deposition and to a aquifer of the Weber Delta subdistrict, lesser extent those of mixed braided few we 11 s h a v e f u 1 1 y pen e t rat e d it. streamflow and mudflow origin. Drillers' Therefore, its lower boundary, water logs of wells in the apex area 'of the bearing properties, and stratigraphy are Delta Aquifer reveal that very coarse nat well defined. The exceptionally grained sediments predominate. Although coarse-grained main section of the Delta the Delta Aquifer has been covered Aquifer ranges in thickness from at with hundreds of feet of deltaic and least 300 ft (90 m) along the Wasatch other deposits, the apex of the main fault zone to less than 100 ft (30 m) Delta Aquifer fan has been reached by west of the Weber Delta. Similar the incision of the Weber River at the gravelly aquifers below the Delta proposed artificial recharge site where Aquifer near the mountain front virtual the river debouches from Weber Canyon. ly disappear in the same distance The top of the main Delta Aquifer westward. These aquifers may be con decreases in elevation radially to the sidered a part of the Delta Aquifer as west and consequent ly is covered with an they are probably in direct hydraulic inc reased thickness of sed iments which communication with it along the mountain part ially and inc reasingly confine it front. hydraulically in that direction. Fonnational thinning of the Delta In its deeply buried position, with Aquifer is accomplished by both pinching its apex or recharge area exposed by out and by lateral gradation to finer erosion, this aquifer is in an excellent grained materials westward and radially situation to receive both natural and away from the source of the sed iment s. art ific ial recharge. Usually alluvial Geophysical surveys indicate that fan aqui fers are situated very c lose to coarser sediments predominate in the the land surface and are not recharged eastern part of the Weber Delta sub by large perennial streams. The main district (Wantland 1956). Alluvial Delta Aquifer has the advantage of being fan deposits typically thin out radially submerged below the regional water table 17 1.n all of its area except at its apex, stationary for some time. The Weber where the perennial Weber River now Delta was then planed off to levels provides a continuous natural source of below 4800 ft (1460 m) and relatively recharge. The Delta Aquifer is probably thin deposits of the Provo Formation fully saturated and confined in all but were left on the top of the delta and in its apex area. In that area and along a few surrounding areas (Feth et al. the nearby mountain front, natural 1966). The ancient lake generally recharge has been occurring, but it receded thereafter leaving the Weber could be increased readily by artificial River to incise its channel across the recharge. A relatively deep water table delta in late Pleistocene and into and apparently high vertical and radial Holocene (recent) time. ly horizontal permeabilities in the Delta and underlying aquifers are Recent Sediments prevalent cond it ions favorab Ie for the success of artificial recharge at the Subsequent ly t he Weber River has proposed site. greatly diminished in flow but it has continued to deposit its fine-grained Deposition of the Delta Aquifer sediments, including reworked deltaic obviously predated the overlying Lake deposits, beyond the delta and has Bonneville delta deposits of the Alpine deposited its coarse-grained sediments Formation of the Wisconsin stage of the in the floodplain of its incised channel Pleistocene Epoch. Pre-Lake Bonnevi lIe through the delta. There may be silts deposits are distinguished in the Weber and clays beneath these coarse-grained Delta subdistrict beneath an unconform sediments in the floodplain, but they ity at the base of the Alpine Formation are probably absent or are of little ( Fe the tal. 1 9 6 6 ) . It i s bel i ev e d consequence in the apex area as observed that the Delta Aquifer is among the in gravel pits and we lls there. Feth uppermost deposits of these inferred et al. (1966), however, suggest the pre-Alpine Pleistocene formations. possibility that impermeable strata capable of impeding recharge may be Lake Bonneville Group present 1.n the proposed artificial recharge area. The intervening Sunset Aquifer probably represents a transition Groundwater Hydrology period as the encroaching Alpine Lake overlapped both older and contemporane Recharge ous alluvial fan deposits of the study area. Thus the Sunset Aquifer could be Underground formations of the Weber assigned to either the early Alpine or Delta subdistrict are recharged prin pre-Alpine stages, but is probably early cipally by the Weber River, underflow Alpine. The Alpine Lake-delta deposits from the Wasatch Front, direct infiltra form practically all of the Weber Delta. tion of precipitation, and probably by Thickness of the Alpine deltaic deposits Some canals and irrigation waters. Most ranges up to a few hundred feet (100 m). of the soils and subsoils along the After formation of the main lake delta mountain front and atop the Weber Delta during the Alpine stage of deposition, are very sandy and porous. Precipita the ancient lake rose from about 5100 ft tion, irrigation waters, and runoff from (1550 m) elevation to its maximum numerous streamlets along the mountain level at about 5200 ft (1580 m), called front seep into these porous materials the Bonneville level. Perhaps the delta and recharge groundwater reservoirs. was enlarged somewhat during that time, Beyond the delta the soils are relative but the lake suddenly was lowered to ly impermeable and recharge to the about 4800 ft (1460 m), called the principal aquifers is considered Provo level, where it remained fairly negligible. Furthermore, the principal 18 aquifers there are mainly confined and west of a point about 1.5 m1 (2.4 km) water 1S leaking upward from them. from the Wasatch Front. The proposed recharge area is safely east of and The average annual flow 0 f the stratigraphically below this area where Weber River for the 20-year period recharge may be prevented by the clay ending in 1947 was 360,000 ac-ft (44,400 layer. This c lay format ion is bel ieved hec tare-me ters) (Fe th et al. 1966). to be that member which caps the main Water available for artificial recharge Delta Aquifer, thus recharge .is acces and long-term flow analysis of the Weber sible to the aquifer stratigraphically River are addressed in the following only below the clay. chapter of this report. Some measure ments have been made of the natural Recharge along the mountain front seepage losses from the Weber River in from subsidiary streams and underflow the apex area. The mean value has been from basement rocks ac ross the Wasatch estimated to be 14,000 ac-ft (2000 ha-m) fault zone was estimated to be approxi annually for the 20-year period end ing mately 33,000 ac-ft (4100 ha-m) annually in 1947 (Feth et al. 1966). Natural for the ent ire 30 mi (48 km) of Wasatch recharge probably fluctuates annually in Front bordering the Weber Delta ground proport ion more to the wet ted area of water district, according to Feth et al. the stream bed than to stream discharge. (1966). Beneath the eastern flank of the Weber Delta alone this may be The shape 0 f the regional piezo roughly 10,000 ac-ft (1200 ha-m) or metric surface of the Delta Aquifer about 8200 ft 3 per lineal ft (770 m3 /m) is clear evidence that it is being along the mountain front annually. Feth recharged by sources along the mountain et al. (1966) further estimate an appre front with a strong component coming ciable amount of water is recharged by from the Weber River itself and/or from d ire c tin f i 1 t rat ion 0 f r a i n fall and fractured substrata in the vicinity of seepage from irrigated areas and canals, the Weber River near the mountain front. but probably very little of this actual Feth et al. (1966) give some estimates ly reaches the Delta Aquifer as most of of flows expected from the Weber River this inferred recharge takes place 1n and from the mountain front. Further areas where the· Delta Aqui fer is c on more, chemistry of the Delta Aquifer fined. In fact, so far as the Delta groundwater is sufficiently similar to Aquifer is concerned, a small portion of that of Weber River water to confirm the the preceding recharge estimate may not Weber River as a source of recharge reach that aqui fer at all, and, there (Feth et al. 1966). Underflow from the fore, a value of 8000 ft 3 /ft (740 m3 /m) mountain front could also be expected to may be a reasonab Ie first est imate of be of similar water chemistry as it all recharge to the Delta Aquifer along would have contact with the same rock the Wasatch Front in the area of the types that the Weber River water Weber Delta, exclusive of recharge encounters upstream. The same similar provided by the Weber River. ities of water chemistry and piezometric gradients exist with regard to recharge Surface Water Hydrology of the Sunset Aquifer. Recharge to the shallower aquifers of the western Weber The Weber River is the prime source Delta subdistrict is from various of water for the Weber Delta area. Its sources including upward leakage from flow is regulated by several dams up the principal aquifers beneath them. stream and water is diverted mainly for agricul tural purposes. Figure 6 shows Feth et al. (1966) report the discharges for the Weber River at Gate existence of a clay formation that way for the years 1920 through 1981. prevents recharge to the deeper aquifers Water available for natural and artifi in the floodplain of the Weber River cial recharge has been quite variable. 19 450,000~------1 300,000 I- W W IJ... I W a:: 250,000 U« ~ 0 ....J IJ... 150,000 50,0004------,------,------,------~------_,------~----~ 1920 1930 1940 1950 1960 1970 I9 a:! YEAR Figure 6. Yearly discharges for the Weber River at Gateway. Statistical analysis is needed to pre water intrusion into these valuable dict future average supplies that might aquifers. Fortunately the lake is very be available physically for artificial shallow and is partially shielded from recharge. these aquifers by lake sediments of very low permeability. The Great Salt Lake is the ultimate sink or discharge level of the East Storage Shore area for both surface waters and groundwaters. Al though the lake is a Feth et al. (1966) have estimated considerable distance from the proposed that roughly 13 x 10 6 ac-ft 0.6 x recharge site, its level does have an 106 ha-m) of usable-quality groundwater indirect effect upon recharge and are stored in the artesian aquifers of ground wa ter fl ow by c ont ro 11 i ng down the Weber Delta subdistrict. They admit stream piezometric levels and hydraulic t hat ina p r act i cal sen s e s om e t h in g g r ad i e n t s. 0 v e r d eve 1 0 pm e n t 0 f the between 380,000 ac-ft and 700,000 ac-ft artesian aquifers in the East Shore area (47,000 ha-m and 86,000 ha-m) may be all could reverse the present lakeward that is recoverable if the head in the hydraulic gradients and induce salt artesian aquifers were pumped down and 20 the upper 50 ft (15 m) were dewatered in groundwater annually flowed through the the Weber Delta subdistrict. They Weber Delta subdistrict between the land estimate that between 80,000 ac-ft and surface and a depth of 1300 ft (400 m). 100,000 ac-ft (10,000 ha-m and 12,000 They believed about one-half of this ha-m) of the foregoing amounts could be groundwater underflow was lost to the readily developed and manipulated as Great Salt Lake and estimated that about active groundwater storage without 9000 ac-ft (1100 ha-m) were wasted dewatering the artesian aquifers. Their annually by flowing wells put to little estimates appear to be very conservative or no beneficial use in the district. for they evidently omitted from their calculations the additional water that leakage between aquifers would afford Delta Aquifer Water Levels when the aqui fers are pumped heavi ly, and they apparently dealt only with the Delta Aquifer. Piezometric contour maps have been developed for the Delta Aquifer and are Discharge shown in Figures 7 through 13 for the Under natural conditions ground ye a r s 1 9 3 7, 1 94 5 , 1 9 5 5 , 1 9 64 , 1 9 7 0 , water discharge is nearly equal to the 1974, and 1980, respectively. The 1964 recharge in a given basin. The total map was taken from Arnow et al. (1964); water in storage normally changes very however, alterations were made to their little in response to climatic fluctu original map. The al tered map depic ts ations. Groundwater discharge in the more of a line source of recharge Weber Delta subdistrict occurs naturally emanat ing from 'the Wasatch Range rather by means of seeps and springs, evapora than a stream source emanating from the tion and transpiration from wetlands, Weber River. The 1974 map was taken and upward seepage into the Great Salt from Stephens et al. (1974) without Lake. modifications. Ad d i t ion aIr e c h a r g e from can a 1 Figures 14 and 15 illustrate the leakage and irrigation return flow as time response of particular piezometric well as increased discharge by wells and contours within the Delta Aquifer. drains have upset the natural balance in Figure 14 illustrates that during the recent years. Increased use of ground period from 1937 to 1955 the 4300-foot water is now being made for municipal piezometric contour fluctuated very and domestic purposes in the sub little. By 1964 the line had traveled district . Piezometric levels have about 6 miles (10 km) to the east, and declined in response to increased has held relatively constant since. discharge for these and other uses. The Figure 15 shows that the 4280-foot needs of this year-round water demand contour line went through the same can be satisfied more effectively by the transition between 1974 and 1980 after a proposed groundwater basin-management steady period from 1937 to 1974. scheme. Feth et al. estimated that in Combined, the two figures show that a 1952 nearly 145,000 ac-ft (18,000 ha-m) 20-foot (6 m) decline in piezometric of water were discharged from cattail levels occurred over a span of approxi areas, salt barrens, water surfaces, and mately 15 years. leakage to Great Salt Lake in the Weber Delta district. Much of this surface The drop in piezometric levels in water and groundwater wastage could be Figures 14 and 15 illustrates that usage salvaged for continued development of from the Delta Aquifer has exceeded the the d ist rict. natural recha-rge. Apparently this condition has accelerated in more recent Feth et al. (1966) estimated that 'years and may continue with anticipated about 40,000 ac-ft (5000 ha-m) of population and land development growth. 21 R3W R2W RIW R3W R2W RIW T6N TSN T3N T3H G'1l ~.... ~'f'.... ~ \ .... ~... <""- <11 ~ ~ t t " " " .---t I T4H S~·GI. I 'tal, .~.. , 9 ... un i-~="1"''''''iF=====;;." .. Figure 7. 1937 piezometric contour map Figure 8. 1945 piezometric contour map for the Delta Aquifer. for the Delta Aquifer. R3W R2W RIW R3W RIW T6N T6N T1!H T3N G'~ G'~ ".... -...... ~ ~.... ~.... <"" <""- '1-", ~ t T4N t 1- -- Scal. &'=~ J:!.... ~ "~-.::::::J ~7-=::=t , .- = I 0 J",,, .. I~' ) ""I .. . , Figure 9. 1955 piezometric contour map Figure 10. 1964 piezometric contour map for the Delta Aquifer. for the Delta Aquifer. 22 tll" '\'1'", '", <~ t ~ T4" Figure 11. 1970 piezometric contour map for the Delta Aquifer. R~W R2W RIW Figure 12. 1974 piezometric contour map Figure 13. 1980 piezometric contour map for the Delta Aquifer. for the Delta Aquifer. 23 R3W R2W RIW LEGEND 1937 1945 T6N ------1955 •••••••••••• e ...... 1964 ------1970 .--.-.- 1974 TSN t Scale Figure 14. 4300-ft piezometric contour line plotted at advancing time intervals. R3W R2W RIW ~ 1937 1945 T6N ------1955 ...... 1964 ------1970 -.--._-. 1974 _0._ .. _- 1980 TSN t Figure 15. 4280-ft piezometric contour line plotted at advancing time intervals. 24 Regimen of Flow Lake or from some hot springs 1.n the East Shore area. The internal structure of an alluvial fan strongly influences The low water table in the recharge the movement 0 f groundwa ter through area is evidence that recharge could be it. Alluvial fans typically have increased artificially. Hydraulic buried channels of coarse-grained gradients can be increased and the Delta deposits radiating outward from their and other aquifers can transmit more apex. These channels are often braided water to areas of heavy groundwater and interconnected as the fan was withdrawals along the general paths built by deposits of the parent stream indicated, but modified somewhat by which played across the fan 1.n numer artificially imposed gradients. ous configurations. Despite the chaotic depositional patterns of alluv Groundwater Quality ial fans when viewed in detail, they tend to conduct groundwater radially In the Weber Delta subdistrict, outward and sl ightly downward when groundwater derived from recharge viewed from a broad perspective. by waters of the Wasatch range is Apparently this occurs in the Delta usually of the calcium bicarbonate Aquifer (see Figures 7 through 13) and a type, but there is evidence that some reserve capacity to transmit water deeper Delta Aquifer horizons yield radially outward from the apex area sodium bicarbonate water (BoIke and still exists. Less extensive alluvial Waddell 1972). This increased sodium fan de po sit s are bel i eve d too c cur concentration probably is due to natural both above and below the main water cation exchange or some other complex bearing member of the Delta Aquifer. reactions underground, and presumably They are believed to be in hydraulic does not render the calcium water communication with one another to incompatible for artificial recharge various degrees. These alluvial fans to these horizons. and other associated deposits readily conduct groundwater away from the Total dissolvea solids (residue mountain front to points of discharge to at l80 0 e) of the calcium bicarbonate the we st. Delta Aquifer well water average be tween 300 mg/l and 400 mg/l and seldom As the coarse-grained materials exceed 500 mg/I. Dissolved solids diminish and .permeabilities are re generally increase with well depth duced westward, the water flow ex 1.n the Weber Delta area. Further pands horizontally (radially 1.n the mo r e, dis sol v e d sol ids are s 1 i g h t 1 y horizontal fan deposits) and sub lower (less than 250 mg/l) in the sequent ly moves generally upward. As groundwater along the mountain front the bedrock formations become con south of and a little north of the siderably deeper at the middle of Weber River than they are close to the basin, a little water can move the River (BoIke and Waddell 1972, downward into the expand ing sedimentary Plate 3) suggesting that recharge sequence, but those deeper formations from the m 0 u n t a i n fro n t may b e 0 f are less permeable and accommodate slightly better quality than that little water movement. What water does of the river. Dissolved solids (res move downward probably moves very idue at l80 0 e) of the Weber River slowly, deteriorates in quality, and water average between 250 mg/l and 350 eventually may emerge in the Great Salt mg/l. 25 ARTIFICIAL RECHARGE Overview stabilization or raising of groundwater levels to reduce pumping lifts and In recent years our understanding costs, and 4) the investigation of of the geology and hydraulics of ground seasonal groundwater augmentation to water reservoirs has improved signifi increase reservoir storage during cantly. These advances in understanding periods of peak demand. are closely related to the accelerated groundwater development and exploitation The second phase of the research witnessed during the last three decades. description is a compilation and analy Al though extensive groundwater suppl ies sis of local geologic and hydrologic exist in Utah, careful management of conditions in the Weber Delta region. this resource will be essential for Because of the complex nature of aqui meeting long term needs. In some areas fers, implementation of any artificial increased groundwater development has recharge project requires a thorough and led to a series of interrelated problems detailed examination of local geologic which have the potential to limit or and hydrologic data to avoid unwanted terminate groundwater usage. Among the impacts from the project. This aquifer most significant of these problems are: investigation phase is the first step in the depletion of storage in groundwater the assessment of reservo~r potential reservoirs leading to reduced well for artificial recharge. The most yields, increased pumping lifts and im po r tan t h yd r 0 g e 0 log i cpa ram e t e r s costs, settlement and subsidence as a include the following: result of decreased pore pressures in fine-grained strata, and water quality 1. Geologic boundaries and lithol de teriora t ion. Consequent 1 y, wa ter ogy of the aquiferCs) and adjacent resource managers are recognizing the units. need for artificially augmenting and managing groundwater supplies in much 2. Hydraulic boundaries including the same way as surface waters are depth to water table, aquifer extent, managed. The primary difference between thickness, etc. surface water and groundwater manage ment is that a new set of rules and 3. Available storage capacity of decisions are necessary which take the groundwater reservoir. This will into account the physics and chemistry depend on the storage coefficient of the of groundwater flow as well as spatial reservo~r as well as the thickness of and temporal variations ~n storage of the unsaturated zone above the reser groundwater reservoirs. vo~r. This report deals first with the 4. Vertical and horizontal com- remedial benefits of artificial recharge ponents of hydraulic conductivity or in general terms. Specific object ives permeability of the groundwater reser include: 1) the conservation and voir. Vertical components are especial disposal of excess runoff and flood ly significant for water spreading or waters, 2) the augmentation of ground basin ponding methods of artificial water storage to maintain or improve recharge. Since groundwater must move present levels of utilization, 3) the vertically to effectively recharge an 27 aquifer, low vertical permeability flat, the vegetative ground cover 1S even in combination with high horizontal left undisturbed, and the soils at the permeability may not be suitable for point of application allow a high such recharge as was shown by the early rate of vertical infiltration (Walton Bountiful experiments (Thomas 1949). 1970). Another problem, common to all types of recharge methods, is the 5. Natural recharge mechanisms. clogging 0 f soil pores by part icul ate In order to be able to quantify the matter. Whenever rec harge water con water balance in a particular reservoir, tains significant quantities of sus it 1S essential to understand the pended material, the sediment must be natural inputs to the system. Since removed before attempting to recharge natural recharge areas are often the the water. Surface spreading of water most likely sites for artificial re is the most economical method in tenns charge, the mechanisms, volumes, and of land preparation when compared extent of recharge should be well with other spreading options. defined. Recharge Basins 6. Volume and timing of water available for artific ial recharge. Recharge basin operating principles Artificial recharge can be implemented are similar to those for water spread to benefit surface water conservation ing. Recharge basins or pits are and flood control. Excess runoff may be excavated or fonned by dikes and wa ter diverted during flood periods or it may is routed or pumped from a nearby source be stored in reservoirs and released into them. Unfortunately, large amounts slowly depending on the mode of oper of silt were introduced into the re ation at the recharge facility. charge basin during the last recharge experiment conduc ted by the USBR in 7. Geochemical compatibility of 1957-58. This resulted in a substantial the recharge water with the groundwater decrease in the rate of recharge. One reserv01r. method of removing undesirable suspended material is to divert the water through The third aspect of the research settling ponds prior to the main re plan involves the assessment of the most charge pits. This method not only effective method of perfonning artifi protects the infiltration perfonnance of cial recharge in the study area. The the ma1n pits, but also introduces most cost-effective practice not only smaller amounts of recharge water will take into account the cost of the into the subsurface from the settling recharge facilities, but also the net ponds. Usually, periodic cleaning of regional benefit s of the art ific ial the basins is required by sc rap1ng the recharge. Three different methods of bottom between recharge periods to recharge have been developed to allow ma in t a i n hi g her in f i 1 t rat ion rat e s . recharge under diverse conditions. Since the infiltration rate is directly These methods are water spreading, proportional to the head maintained recharge basins or pits, and injection in t he basin, 1 arge infil t rat ion rates wells (Walton 1970). can be expected under favorable condi tions. Water Spreading Inject ion Wells Water spreading on the land surface is accomplished through the use of Of all the recharge methods, feeder ditches and outlets to evenly recharge of the groundwater reserV01r distribute water over the desired area. through wells encounters the most This method of recharge is most e ffi difficulties of operation. Sever<1l cient if the land surface is relatively potential problems, which directly 28 affect recharge rates, must be addressed either surface spreading or recharge before injection wells are operated. basins but the ability to deliver These are summarized in two basic recharge within an aquifer at any categories. desired location may in some cases override the cost considerations or be 1. C logging of the aqui fer by the only method physically possible at a suspended particles, entrained air, given site. algae, and microorganisms. Any sediment or floating material carried into the The fourth phase of artificial well will be filtered out in the aquifer recharge pI anning for this research zone surrounding the well. Micro involves the prediction of the effec organisms growing within the well and in tiveness of the proposed recharge method the surrounding aqui fer also reduc e the and its potential impact on groundwater hydraulic transmitting capacity of the users. This was accomplished by first aquifer. Entrained air carried into the calibrating a computer model of the aquifer effectively reduces the hydrau groundwater reservoir based on the data lic conductivity by reducing the avail compiled in phase 2 of this investi able pore space for conveyance of gation. The computer model was then water. used to simulate historical ground water level behavior and to estimate the 2. Physico-chemical processes spa t i a 1 and tern p 0 r aId is t rib uti 0 n 0 f which also clog the aquifer. Sometimes natural recharge and basin discharge. the injected water is of such a nature Alternate artific ial recharge prac t ices that chemical reactions take place and their impact on groundwater levels when commingled with the groundwater. ~re then examined. Ox ida t ion s tat e s, pH, t em per a t u res , solubility levels, and other character Field Conditions at the istics may differ to the point that Weber Delta Site physical and chemical reactions take place fonning colloids or precipitates. In the first section of this report Chemical reactions on silts and clays a review of the published geohydrologic may reduce aquifer hydraulic conduc data was presented including some inter tivity through ion exchange, floccula pretation from the present research. It tion of clays, and other reactions is evident that much infonnation on the between the aquifer and the recharge geology and hydrology of the Weber Delta water. subbasin is available and extensive field invest igat ions are not necessary. These problems are very difficult Feth et al. (1966) describe the zone to correct because they occur deep most favorable for rec'harge as a strip within the aquifer system. Desilting of of land in the Weber River valley about a clogged well must be accompl ished by 1. 5 mil e s (2. 4 km ) in wid t had j ace n t reverse pumping or intense development to the mountain front. The writers work instead of the easier less expen identify this strip as the principal sive method of surface scraping utilized rec harge area. in recharge basins. Biological growth removal would require special pro Natural recharge consists of two ced ures. These proc edures migh t inc 1 ud e parts: 1) Channel seepage where int roduc tion of a killing agent, then the Weber River crosses the prin reverse pumping and proper disposal to cipal recharge area (estimated to be remove the contaminant and microorganic 16,000 acre-feet (2,370 ha-m) annually) growth. and 2) mountain front recharge or underflow from the Wasatch Range plus Ope rat i on of r ec harge we lIs may direct recharge from precipitation and have considerably higher costs than irrigation seepage (estimated to be 29 approximately 46,000 acre-feet (5,520 canyons to store high runoff streamflow ha-m) annually). The principal recharge for use during the low flow seasons zo n e i s c h a r act e r i zed a s abe 1 t 0 f of the year. Water use expanded to the gravel and sand deposits that will groundwater system. The municipalities readily absorb the water made available at last occupied so much farmland that by nat ural recharge. water supply requi rements in the Ogden area began to shift from irrigation to Artificial recharge experiments domestic use. were performed in the principal recharge area in 1953 (Feth et ale 1966) and in Beginning in 1908 the flows of the subsequent years using surplus flows Weber River near Plain City were mea from the Weber River. Water was divert sured. A stream gage was also installed ed into a pit having an area of 3.25 on the Weber River near Gateway and acres (1.32 ha). The experiment demon began operation in 1921. Other stream strated that a continuous infiltration gages have been used at various loca of 7 cfs/acre (490 Msec/ha) of pit tions but their records are quite short. could produce a temporary increase in a The stream gages near Plain City and nearby observation well of 34 ft (10.4 Gateway demonstrate the changes in m) • The i.nitial depth to water is at water use and the present availability least 217 ft (66.1 m) which indicates of water. signific ant storage c apaci ty exists for artificial recharge in the principal In the early 1950s the U.S. Bureau aqui fers there. These experiments also of Reclamation began construction of the demonstrated that the vert ic ial hyd rau Weber Basin project. This project lic conductivity in the principal included construction or enlargement of recharge area is relatively large. dams, installation of diversion struc Horizontal hydraulic conductivities in tures and conveyance systems, building the water table aquifer of the Weber of power systems, drilling wells, and Delta District have been estimated from diking a portion of the Great Salt Lake pumping tests to be on the order of for storage of fresh water. This system 30,000 to 40,000 gal/ft2 /day (1,222 to was essentially in operation by 1958. 1,630 m3 /m2 /day) and it is likely There have been no major changes in the that vertical conductivities are nearly system since that time. as large as this value. Water for artificial recharge The volume and timing of water purposes must be available at the available will depend on the avail Ga teway gage to be of us e at the pro ability of surplus water, and will be posed site. In 1936 the Weber River discussed subsequently. Decree specified about 1500 cfs of water rights between the Gateway gage and the Discharge Hydrographs and confluence with the Ogden River. In Water Availability conjunction with the Weber Basin pro ject, the USBR filed on most of the Early settlers 1n the Ogden area remaining water in the Weber Basin. diverted surface water to irrigate Since the 1936 decree, some water uses the crops required to sustain the lives have changed. Some power rights have of the settlers and their animals. been transferred as have some water Municipal use was very small. As rights. It would seem that the current additional settlers arrived, more water high water right should be higher than was diverted to supply the increased the 1500 cfs specified in 1936. How agricultural needs. Eventually, munici ever, the Weber River Water Commissioner pal d istribut ion sys terns were required has stated that the current demands can for Ogden and nearby commun1t1es. Dams be met with 700 cfs at Gateway. This were built in the Weber and Ogden conforms to the pattern of filing for 30 more water than can be used at the physically there appears to be 5 to time of filing so that water will 10 cfs of excess water available. Some be available for increased future of the options for obtaining the water needs. The major use of water below for recharge operations are: the gage near Plain City is for the bird refuge which requires a maximum of 1. File for water rights on excess ab out 200 c f s . Maximum us e is not runoff. These flows would occur for continuous as the maintenance of a only 3 months at the most and would constant water level during the nesting involve very high flow rates. High season only is critical. During the fl ows are very di fficult to handle for remainder of the year, the water re recharge. quirement is governed by maintenance of the habitat. 2. Purchase sufficient water rights from individuals. Figure 16 shows the average monthly flows at the Gateway gage for the 3. Purchase water from the Weber period of record prior to the Weber Water Conservancy District. project (1921-1957), and for the peri od subsequent to the project (1958- 4. The District might choose to 1977). Obviously major changes have donate the 5 cfs to help water users in occurred during the annual high run the lower areas who have been paying off period due to the increase 1n taxes as well as water use fees for many storage capacity upstream from the years. gage. The fl ows from Jul y through March have decreased only slightly. 5. A fil ing could be made on an The changes during April through June old USBR appl ication that has not been have been from 200 to 500 cfs. Figure perfected and the point of diversion 17 shows the duration curves for these could be changed. same two periods of record. The maxi mum flows have been significantly In summary, there seems to be reduced while the flow greater than sufficient water to provide 7500 ac-ft 700 cfs has been reduced from 23 per per year for artificial groundwater cent to 16 percent of the time. Figure recharge. This wou1 d be only about 2.5 18 gives the duration curves for the percent of the amount of water passing Weber River near Plain City for three the gage at Plain City from 1958-1977. periods (1908-1957, 1958-1977, and The main problems are to complete the 1908-1977). The maximum flows have needed 1 egal and insti tut ional arrange been reduced to about one-half of ments, obtain the cooperation necessary the preproject value, and the flows to get the desired amount of water to occurring up to about 75 percent the recharge site, and have the needed of the time have been reduced. Flows facilities constructed and operated at greater than 200 cfs occur just under 50 optimum costs. percent of the time. Figure 19 shows mean monthly flows near Plain City. Proposed Operation for Since 1958 there has been about 300,000 Artificial Recharge ac-ft per year flow past the Plain City gage. A significant portion of that The proposed operating system for flow goes to the Great Salt Lake. It the Weber Delta artificial recharge would seem that 5 to 10 cfs of flow project would consist of a diversion would be avail ab"le at 1 east 50 percent works and two basins in series. The of the time. However, physical and first basin would act as a settling pond institutional availability do not always to remove sediment before the water coincide. This problem would have to be rea c h est hem a i n r e c h a r'g e bas in. reso lved. Floating debris will also be removed 31 2000 -- 1921-1957 ---- 1958-1977 ~ 1500 ....en rEQL (.) 1075 -'200- 1000 -94Ef ----- 809 I _5_~~_ 500 481 F----- L~_~~_ 350 255 269 247 234~ 446 217-l i6"Ef -I175t263"l-205- o OCT NOV. DEC. JAN. FEB. MAR APR MAY JUN. JUL. AUG. SEP. Figure 16. Average monthly flows, Weber River at Gateway, 10136500. 4000 -- 1921-57 3400 .... 0.··· 1958-78 2800 q en - 2200 -(.) 9 g3: l.L 1600 ~... 1000 ~. ·o.~ 400 ····· .... 0··· .••. 0····· ... 0 ...... ~ 00 25 50 75 100 FLOW EXCEEDANCE I N PERCENT Figure 17. Flow duration curves for the Weber River at Gateway, 1921-1957 and 1958-1978. 32 1.0 -- 1908-1957 - --- 1958-1977 0.9 · .. ·····1908-1977 0.8 - 0.7 --n 0.6 : ~I.J.. ~ W 0: 0.5 : I CJ) ~ c3 0.4: Z 2500 2348 -- 1908-1957 ----- 1958-1977 2000 1872 en 1500 ...... o 1144 1000 895 ----1019 885 1---- 500 432 483 604 -572 383 249 354 263 301- III 69 r 148 ·1'246 l 277 281 106--t-, ,-;--80 1' '1 o OCT NOV DEC. JAN. FEB. MAR. APR. MA~ JUN. JUL. AUG. SEP Figure 19. Average monthly flows for the Weber River near Plain City, 10141000. 33 before reaching the main basin. These water are wasted into the Great Salt basins will be divided into subbasins Lake annually as a result of high spring fo r opera t i onal purpo ses . Th e fi r s t runoff. If utilized, this water would basin would also act as a recharge basin allow high head operating condit ions in although its capacity to function as the recharge basin. Increased infiltra such will reduce with time. Previous tion rates are obtained as water depth tests using recharge basins have proven increases. During low flow periods any this method tobe appropriate for available water would still be used and artificially recharging the groundwater the recharge basin operated under low supply. head conditions. A computer mode I can be used to determine the quant it ies of Preliminary studies on water avail recharge water needed and the periods in ability indicate that vast quantities of which they should be applied. 34 APPLICATION OF COMPUTER MODELS As part of this invest igation, a Groundwater Model computer model simulation of regional groundwater flow in the Weber Delta area The steps for model implementation was developed. The model uses the desc ribed by Townley and Wilson (1981) recharge basin method for applying for AQUIFEM-l are: recharge water and places the basin in the proposed recharge area which 1. Data collection. Required occupies the same location ut il ized by model input s must be defined and col- the USBR during the recharge experiments lected. of the 1950s (see Figure 2). 2. Conceptual izat ion. The avail The use of a computer model facili able data and knowledge about the system tates the analysis and forecasts of must be transformed into a readily possible outcomes of an artificial understandable form. This step includes recharge project. Effects upon piezo such things as definition of boundary metric water levels under diverse conditions, initial conditions, system conditions can be predicted, and inputs, and governing equations. decisions made regarding the economic implications of alternative conditions. 3. Discretization. Each known condition must be altered in some manner Discharges of the Weber River and such that continuous events or bounda their related probabilities had to be ries are changed to discrete events or analyzed first using stochastic river boundaries. This includes approximating flow models. The results of this a well by a node or element, or by using mode 1 ing were as ses sed wi th known wa ter a series of straight lines to approxi rights to obtain a net probable flow mate a curved boundary, etc. available for use as recharge water. These results then allowed decisions to 4. Parameterization. In this be made concerning alternate water stage inputs such as permeability, etc., supply sources availab Ie for art ific ial are changed to obtain a closer match groundwater recharge. between simulated and historical events. This is also known as calibration/ Three models were utilized during verification of the model. this study. The first is a finite element hydrologic groundwater model 5 • A P P 1 i cat ion. Th e c om pIe ted developed at the Massachusetts Institute model can be run to simulate or predict of Technology (MIT) and known as the results of various management AQUIFEM-l. The second is based upon a options. stochastic generation method developed at Utah State University (Canfield Since the data used for this study 1983) which generates yearly river were compiled from other sources and not flows. The third is a statistical by additional field work, the model disaggregation model which calculates implementation process will begin with monthly streamflows from generated conceptualization and the data will ye arly streamfl ows. be presented in later sections. 35 Conceptualization Q = Q(x,y,t) net flux into the aquifer from point Governing equation. Groundwater or distributed movement throughout the study region is sources (and three dimensional in nature. Not only sinks), [LfT] does water move westward from the mountain front, but it also radiates K' K' (x, y) = v e r tic alp e rm e- ou twa rd as it move sand strong ve rt ic al ability of the flow components may occur. However, leaky semi-pervious, three-dimensional flow models require a layer a b ov e 0 r great deal more data concerning the below the principal adjacent aquifers than is available in aquifer simulated, the Weber Delta area. For this reason a [ LfT] two dimensional model with a leaky B' = B'(x,y) = thickness of the aquifer option was chosen to represent . sem1-perV10US. flow in the horizontal (x-y) plane. layer, [L] AQUIFEM-l is a two-dimensional, ha = ha(x,y,t)= piezometric head in finite element model capable of simu a vertically lating a wide variety of geohydrologic adjacent aqui conditions. The governing differ fer, separated ential equation used in the model for from the ma1n essentially horizontal groundwater aquifer by the flow in a nonhomogeneous, anisotropic semi-pervious aquifer with leakage is: layer, [L] a S ah + T ah) x,y Cartesian co ay ( yy ay at ordinates (princi K' pal axes of the + Q + (h - h) (1) hyd raul ic c onduc B' a tivity or trans missivity tensor), where [ L] S S(x,y,t) = aquifer storage co t = time [T] efficient Boundary conditions. Specific h h(x,y;t) = depth averaged boundaries must be defined for the model pie zome t ric head, which relate as closely as possible to usually denoted natural field conditions. Table 1 lists cP for confined the available modeling capabilities of aquifers, expressed AQUIFEM-l which must be considered for in units of length proper model application. For further [L] details see Townley and Wilson (1981). aqui fe r t ransm i s sivity in the x Groundwater recharge in the study direction, express area originates mainly from infiltration ed in units of through the bed of the Weber River and length and time subsurface inflow through faults and [L2fT] fissures along the mountain front. The Wasatch mountain front with groundwater aqui fe r t ransmi s flow across it was selected as the sivity in the y eastern boundary marked A-B in Figure direction, [L2fT] 20. 36 Table 1. Modeling capabilities of AQUIFEM-l. Boundary Conditions 1. Specified heads are known 2. Specified heads are known with time 3. Fluxes are known (if flux is zero a streamline exists) Sources and Sinks 1. Point or area sources 2. Constant head source with leakage flux 3. Leakage from an adjacent aquifer 4. Flowing wells 5. Evapotranspiration 6. Springs 7. Land drainage B. Geologic faul t s 9. Partial penetration of wells, streams, lakes, and springs 10. Excavation dewatering ...... R3W R2W RIW EIr--~-_.... ...... ' .. ' r Agricultural Area T5N ' ...... ,... '. u~ •••••• '=9,.>. ••••••• Base ---lI1------=::...... ------"r------:------'\c-t-Military ----;~-----.---+-- ~ .' Area <',.>. • <~ use boundry...;-············ ~ .... ,.. - ... ". •••• .•.....• e \'\ G -...... ~~ ...... " ...... sq';:' ...,;>0 Scale 3.!1!FMi.l>l,,~ss~§SI!!=2 ===rSSSS>SSSSli1"~,o!======:!~ mi les Figure 20. Comp~ter model boundaries and simplified land use patterns. 37 The northern and southern model simpl ified into an elemental flux over boundaries were obtained after piezomet one or more finite elements much easier ric contour m.aps were prepared for the than developing a finite element grid years 1937 through 1980 (Figures 7 to with a node at each well location. 13). The general orientation of contour The Weber River is a substantial lines along the northern and southern source of recharge for the Weber Delta· sections of the map were virtually un and appropriate nodes are identified changed through time. These contour later to represent its inflow. lines represent lines of equal piezomet ric head and groundwater moves along Figures 7, 10, and 12 indicate the streamlines perpendicular to them. possible existence of a recharge source Therefore, boundaries B-C and E-A of producing a piezometric mound along the Figure 20 were selected along stream western boundary. This recharge was lines across which no flow occurs. This modeled using an elemental source whose constitutes a no-flow boundary condition value was altered in direct proportion for the model. to mountain front recharge. How this water moves from the mountain front to A no-flow boundary condition was the mound is not known. A poss ib Ie also used along the western boundary mechanism for such an occurrence could C-D-E. Well logs indicate that lower be the lenticular structure of the Delta permeability silts and clays predominate Aquifer. Direct bedrock (deep) connec in the main Delta Aquifer to the west. tion is also possible. This tightening of the aqui fer system Well pumpage was modeled by elemen has the effect of increasing the move tal sinks. The large number of wells ment of water vertically, thus feeqing made it impractical to model them as shallow aquifers in the vicinity of the point sources. Pumping data and est i Great Salt Lake. The presence of mates were obtained from Thomas et al. numerous springs and artesian wells in (1952), BoIke and Waddell (1972), Feth the western reaches of the study area et al. (1966), and from open files of support this concept. the United States Geological Survey in In order to model the principal Salt Lake City, Utah. Those records aquifer, its thickness and elevation revealed the three main water uses are must be known. The elevations for the irrigation, munic ipal and industrial, top and effective bottom of the main and mil i tary. member of the Delta Aquifer were taken Land used for irrigation, municipal from Figures 3 through 5 and also and industrial, and military purposes estimated from logs of intervening was obtained (Weber River Water Qual ity we lIs. Contour maps showing the top of Planning Council 1977) and generalized the main member of the Delta Aquifer into the areas shown in Figure 20. Each (Figure 21), the effective bottom of the area will be redefined 1n a later aqui fer (Figure 22), and its effective section after the finite element grid 1S thickness (Figure 23) were constructed developed. using these data. Finite Element Grid Sources and sinks. Two basic approaches are available for modeling A finite element grid is a type of water sources or sinks (withdrawals). graphical representat ion 0 f an area to The first method uses a point source or be modeled. Each node can represent a sink, which best simulates the effects point source or sink as well as a of individual wells. The second method location reference for either known uses elemental sources or sinks which or calculated heads. Lines connecting can simulate discharge conditions or nodes can represent line sources such as withdrawal spread over an area. Also, mountain front or river recharge. an area with numerous wells could be Similarly each element can represent an 38 R3W R2W RIW T6N T5N T4N I I I I ..... --- -- ..... ------+i_ 1.r :~. .' Ylii Figure 21. Contours on the top of the main Delta Aquifer. areal source or sink. Such flexible remainder of the river was not modeled conformation to boundary conditions and for two reasons; first, the permeability natural features is not as easily oft her i v e r bot tom dec rea s e s wit h accompl ished us ing a finite difference distance from the mountain front and model due to its required rectangular second, the confining layers which grid structure. produce pressurized conditions within the Delta Aquifer prohibit river re In the initial stages of developing charge from entering directly into the the finite element grid, nodes were deep aquifer system. placed at as many principal well loca tions as possible. This was done AQUIFEM-l utilizes simplex trian so that the historical data for those gles and calculates values based on wells could be easily compared with the linear interpolation between nodal model results. Nodes 2,6,11,18,28, points. For this reason computational 39, and 52 were used to represent accuracy increases with decreased the contribution due to the Weber River distance between nodes. It ~s desirable (see Figures 20, 24, and 25). The to place a larger number of nodes in 39 R3W R2W RIW Figure 22. Contours on the effective bottom of the Delta Aquifer. regions where conditions vary more 2. Triangular elements should be rapidly than in others. Since recharge kept as nearly equilateral as possible comes mainly from the Weber River and to avoid unnecessary computational the mountain front, a larger number of error. nodes were placed in that zone so that 3. The rat ios of the areas of two better hydrol~gic simulation could be adjacent elements should not exceed obtained. Similarly, fewer nodes were the range of 1/5 to 5/1. placed toward the western boundary because groundwater conditions are much Figures 24 and 25 illustrate the more stable there. finite element grid selected for the Weber Delta area with the numbering sys Three important rules were followed tems to identify the nodes and elements. for the construction of the grid: Computer Input 1. All nodes must be at the This sect ion discusses the basic vertexes of the triangular elements. principles of computer input and its 4(} R'3W R2W RIW T5N Sl...l~ll:: c:.:.~~~:.s..'\."il-_ -- .-L'I,~,,::,::~ ... __ . "3? C Figure 23. Effective thickness of the Delta Aquifer. formulation based on knowledge about the report s obtained from the United St ates system. There are 168 nodes and 294 Bureau of Reclamation (1982) and Feth et elements in the computer model grid. At al. (1966). These data along with data each of these nodes or elements there generated by the authors gave aqui fer must exist data defining the conditions properties which describe the system which either exist or are imposed upon insofar as the data permit. Aquifer the system. The computer input data properties required for input are listed include: 1) initial hydraulic head, 2) ~n Tab Ie 2. recharge, 3) hydraulic conductivity or Hydrologic characteristics. Sever transmissivity, 4) storage coefficient, al hydrologic parameters are required and 5) pumping rate. Each of these are before a computer model can be imple discussed below. mented. These are discussed below. Aquifer characteristics. Much of 1. Recharge. Best estimates of the data utilized came from notes and subsurface mountain front recharge (Feth 41 55 45 44 123 Figure 24. Nodal numbering system for the finite element grid Figure 25. Element numbering system for the finite element grid. 42 Table 2. Aquifer properties for the main member of the Delta Aquifer and sources of information. Aquifer Property Sources of Information Bottom elevation Effective bottom elevation as shown in Figure 22. Thickness Effective thickness as shown in Figure 23. Hyd raul ic conduc tivity Initial values came from well testing done ~n the 1950s (Feth et al. 1966). Storativity Initial values were obtained from well testing done ~n the 1950s (Feth et al. 1966). Storage coefficient A uniform value typical of unconfined aquifers was used since no data were available. K' /B' Hydraulic conductivity of the leaky layer divided by its thickness was initially taken as a constant and was based on data from Feth et al. (1966). et al. 1966) indicated that the flow 2. Discharge. Discharge occurs volume should be in the order of 30,000 within the system through one of two ac-ft (3700 ha-m) per year. This was methods, natural flow paths or well distributed along the mountain front in discharges. Natural discharges of water a manner which weighted the areas adja through the confining layer into the cent to the canyon mouth more heavily Sunset Aquifer were calcul ated by the than those distant from it. The distri computer mode 1. bution in terms of percent of average flow as utilized in the model is shown Pumping discharges were extremely ~n Figure 26. difficult to acquire. The region contains numerous wells many of which As explained earlier the piezo are no longer on record with the State metric contour maps indicate that there Engineer's office. Also many of these is an apparent source of recharge in the wells are small domestic or irrigation western part of the study area. The wells for which pumping data are not computer model included this recharge recorded. The best data, available as an additional part of mountain front for a determination of what pumping has recharge. A later section will discuss occurred were found to be that published the amount of this recharge source as yearly by the United States Geological derived during calibration. Survey in the annual report s on Ground water Conditions in Utah. These data, Weber River recharge fo r the area however, have only limited information was based solely on river seepage with regards to both the specific study studies completed in the 1950 by the area and the pumping distribution within Bureau of Reclamation. In those studies that area. river recharge was found to vary from 0 to 15 percent of the total river flow. The yearly data published include A constant value of 7.8 percent of the the ent ire region known as the East river flow was utilized throughout time Shore area of which the study area is a and applied as equivalent quantities portion. Values taken from the Weber of nodal recharge along the appropriate River 208 report (Weber River Water length of the river. Quality Planning Council 1977) indicate 43 NORTH SOUTH lLI v_ lLI 0 0 0 lLIlLI 0 Z 00 Z zz00 Figure 26. Distribut ion for mountain front recharge showing percent 0 f average fl ow per foot. that the study area includes approxi Municipal and industrial pumping mately 50 percent of the total East estimates were obtained on a yearly Shore area agricul tural acreage. By basis from the United States Geological assuming an equal utilization of water Survey. These values were used without per acre of land the quantities given on al terations. Figure 28 was prepared to a yearly basis c an be broken down into illustrate the recorded changes in project area pumped irrigation totals. municipal and industrial pumping with These values are then added to indus time. trial and munic ipal pumping rates for the year to obtain a project yearly Areal withdrawal distributions were to ta 1 . obtained with the aid of the Weber River 208 study (Weber River Water Quality This process was continued for the Planning Council· 1977). Utilizing land years 1968 to 1981. The values were use patterns presented therein and then compared with the pub lished East knowledge about the locations of munici Shore area totals and tabulated as shown pal and industrial wells, three separate in Tab le 3. When plot ted as in Figure pumping regions were defined as shown in 27 it is seen that there is a break in Figure 29. Region 1 represent s the the slope around the year 1972. After agricultural pumping zone, region 2 the that time there appears to be no change municipal and industrial zone, and in t he annual average pumping rate region 3 a zone of high pumping concen of approximately 63 percent of the total tration consisting of wells operated by East Shore area pumping. This percent Hill Air Force Base. age was held constant after 1972. Table 4 lists the pumping data and 3. Adjacent aquifer heads. references which were used in conjunc Piezometric heads within the Sunset tion with the above method to obtain Aquifer overlying the Delta Aquifer have pumping withdrawals throughout time. an important impact upon leakage either 44 Table 3. Project withdrawal percentage of East Shore area tota1s. a USGS Proj ect Municipal GWC Percent Year Irrigation Irrigation & Industrial Total Report of Estimate Est imate Tota1b Total 1968 27,100 13,550 10;359 23,909 46,400 51.53 1969 27,400 13,700 11,777 25,477 48,400 52.64 1970 17,000 8,500 13,061 21,561 39,000 55.53 1971 17,700 8,850 13,722 22,572 40,600 55.60 1972 16,400 8,200 16,170 24,370 40,000 60.93 1973 1974 17,500 8,750 21,778 30,528 47,000 64.95 1975 17,300 8,650 15,029 23,679 38,000 62.31 1976 17,000 8,500 14,177 22,677 37,000 61. 29 1977 15,800 7,900 23,881 31,781 48,000 66.21 1978 15,700 7,850 13,884 21,734 36,000 60.37 1979 1980 16,000 8,000 20,877 28,877 45,000 64.17 1981 8,600 4,300 19,294 23,594 36,000 65.54 aTabu1ated values are in ac-ft/yr. bVa1ues obtained from Yearly Groundwater Conditions ~n Utah reports. C,!) 100 Z a.. :E 90 ::> a.. --l 80 ~ 0 70 t- lJ... 0 60 lJ.J C,!) 50 ~ Z lJ.J U a:: lLJ a.. 1965 1970 1975 1980 YEAR Figure 27. Project area pumping withdrawal as percentage of East Shore are totals as a function of time. 45 Table 4. Summary of well discharge history for East Shore area, Utah (ac-ft). Year Irrlgation Industrial Pub11C Domestlc Total Sourcea Comments + Stock (Areas are for East Shore area unless otherwise noted) 1939 15000 2 Davis County wells 26000 3 Small diameter wells 1946 8800 15000 2 Davis County wells 1954 33400 4 Weber Delta District (T3N-T7N) 1960 10000 3 1961 15000 3 1962 13000 3 1963 36000 1 15000 3 ·1964 55000 1 19000 3 1965 59000 1 21000 3 1966 55000 1 22000 3 1967 53000 1 24000 3 .j::- 1968 27100 6800 12500 b 46400 1 0'> 20000 3 1969 27400 6600 14400 b 48400 1 21000 3 1970 17000 6400 15600 b 39000 1 1971 17700 6500 16400 b 40600 1 1972 16400 6900 18100 b 40000c 1 1973 41000C 1 1974 17500 7800 24400 b 47000c 1 1975 17300 6300 17600 b 38000c 1 1976 17000 6100 17500 b 37000c 1 1977 15800 6700 29300 b 48000c 1 1978 15700 5900 18100 b 36000c 1 1979 46000c 1 1980 16000 45000c 1 1981 8600 6300 21000 b 36000c 1 a1 Utah Division of Water Resources, U.S. Geological Survey, 1963-1981; 2 Thomas et al. 1952; 3 BoIke and Waddell 1972; 4 Feth et a1. 1966. bIncluded in irrigation estimate. CAdjusted values given in 1982 Groundwater Conditions in Utah Report, page 8. -Q) - Total pumping ~ Q) 40,000 Municipal and Industrial (Region I) o~ Irrigation (Region 2) ... . -o Hill Air Force Base (Region 3) .' 0...... • ••• 0 . 30,000 · . • ,0-', ::. ,,' . " '. . ·'0.'· '.'",', .': : ',. ~. 20,000 10,000 ------_./""- .... 1950 1960 1970 1980 YEAR Figure 28. Historical pumping rates used for the Weber Delta area. into or out of the Delta Aquifer. Early Limitations and Neglected Features estimates of the heads in the Sunset Aquifer were obtained from several Several limitations to the model Water-Supply Papers published by the and input exist. Perhaps the greatest United States Geologic Survey. These is the fact that a three-dimensional publications, however, contain very aquifer system is being modeled by a little data for this adjacent aquifer two-dimensional model with vertical after mid 1960. leakage. Any vert ic al fl ow from the Sunset Aquifer would tend to decrease 4. Fixed head nodes. In 0 rder fo r the heads in that aquifer. The computer the computer model to converge upon a model is unable to account for that solution it is usually required that one dependent interaction internally and any or more nodes be specified as a constant head adjustments must be done manually. head node(s). With the physical bound ary conditions as given in the modeled To the wr iters I knowl edge only one area, a we 11 de fined cons tant head estimate of mountain front recharge has node does not exist. The only region been made for the proj ect area. Addi which might be suitable for such a tional study would probably firm up this condition is along the western reaches estimate. The unknown quantity of deep of the model in the area of the Great recharge occurring along the western Salt Lake. Node 164 was chosen as an reaches of the project area has already approximation to a constant head node been ment ioned . due to the fact that the piezometric heads of the Delta Aquifer appeared to Pumping rates include some error change less in that region than any ~n terms of quantity and also in terms othe r. of areal distribution. 47 R3W R2W RIW Municipal and T5N Industrial Pumping (Region ) T4N ------~-I---! c...'~.~ ~ ~.},,~ ---, -, - . --~ rr. I,." Figure 29. Municipal and industrial, irrigation, and military pump~ng regions. Weber River recharge is not a distributed by regions as assumed, but constant percentage of the streamflow as consists rather of an unknown distribu assumed but varies with depth of flow tion. and submerged area. The aquifers involved consist of a The streamlines which make up the wi d eran g e 0 f all uv i a 1 mat e ria lsi n northern and southern boundaries of the a complex array and distribution. Any model actually somewhat vary with time. values defined as pertaining to such a Since a gridwork .cannot change within system are obviously an estimate or the model at advancing time steps, an simplification of true conditions. average streamline posit ion was chosen. Statistical Models The withdrawal of wat~r from In this study a statistical model the Delta Aquifer ~s not uniformly was developed ~n order to study the 48 probabil ity of having water availab Ie historical sequence there must be for groundwater recharge. Water sufficient data available for analysis. may be considered available when the A rough estimate of the minimum number flows within the Weber River are greater of required data points for a valid than the concurrent water rights. If a model 1S in the order of 60 (Canfield statistical model shows that water 1983). This does not indicate that only availability occurs with a small prob 5 years of monthly data are required for ability, then an alternate plan must be monthly generation in spite of the fact considered. Such a plan might include that 60 data points would be available. options such as operation only during In keeping with the above rough estimate available flow periods, or utilizing we would need 60 data point s for each purchased water. period over which natural changes occur. Therefore if a yearly trend was desired The time period for which any we wo u 1 d r e qui r e 6 0 yea r s 0 fda t a . generated river flows are calculated The determination of whether or not is an important factor when considering there exists sufficient data for the available water. If the generated Weber River at Gateway to perform a series and thus the available water are stochastic analysis was done with the based on yearly intervals alone, impor aid of a doub Ie mass plot. Figure 30 tant fluctuations in river flows would compares cumulative flows for the be totally missed. For example, during Weber River at Gateway versus those low flow periods with a simultaneously for the Weber River near Oak 1 ey, Utah. low water right demand a small change in The _ Oakley station is above any major river flow would result in available development and the flows in the Weber wa ter dur ing that period. The same River at that point are taken as un sequence of flows when averaged over the altered. When cumulative flows occur entire year might, however, be very ring at one station are plotted against different and even indicate that no flow the natural cumul ative unaltered fl ows was availab Ie. at another, an indication of the usable length of record of the first can be The degree to which a model is made. Figure 30 shows that there exists broken down depends upon the degree a b rea kin s lop e bet we en the two of accuracy desired and the amount of stations around the year 1968. What information available. The decision this means is that for a statisti therefore hinges upon factors 1n both cal model only the data obtained after the resource and time domains. Much of that date should be used in the analy the data gathered for analysis in this sis. If this rule is followed explicit project is based on monthly values and ly, then only 14 years of record exist therefore the resources would support a over which statistical parameters can be similar breakdown of the statistical obtained. In order to accurately model. The time constraints likewise generate both seasonal and long term indicate that a monthly breakdown should streamflow fluctuations, the statistical be used. mode 1 wa s divided into two part s : 1) The statist ical procedure involves annual time series generation based on a the artificial generation of a sequence comparison with nearby long record gages of river flows which possess the same and 2) monthly time series generation to statistical characteristics as the establish seasonal flows. original series, and is not intended to suggest that future events will follow Annual Time Series Generation the same pat tern as those produc ed by the generated series of flows. The most widely used form of stochastic generation uses the auto In order to reliably reproduce correlation funct ion. The autocorrela the statistical characteristics of a tion funct ion desc ribes the degree of 49 xlO S 5.0 f' I 4.0 Co) 0 -.s:: 0 :;) - 3.0 >-.. 0 •G) 0 -(!) a 2.0 -~ G) a::.~ ~ G) .Q 1.0 G) ~ O.O+------r------,------r------~----~ 0.0 1.0 2.0 3.0 4.0 5.0 xI05 Weber River near Oakley. Utah (ac-ft) Figure 30. Double mass flow plot for the Weber River at Gateway and the Weber River at Oakley, Utah. sequential dependence or correlation in those found at the Gateway Station. a historical time series. If the James et al. (1979) published what autocorrelation function is transformed they called present modified flows to the frequency domain it is known as for the Weber River at Plain City. the spec tral dens ity funct ion (Jenkins These values were calculated on a and Watts 1968). Once such a conversion yearly basis so as to account for man I s is made the spectral density can be used act ~v~ ties as though they had occurred directly to generate stochastic series. since the beginning of the available The benefit of using the spectral record. A comparison between the dens ity is that if a river stat ion can characteristics of the said modified be found with a similar spectral density flows and the Gateway Station is out and a longer record, the spectral lined next. density of the longer record can be utilized to forecast flows at the A program utilized to calculate the desired location (Canfield 1983). spectral density function (called . STAT. FOR) can be found in Appendix B. Since the purpose of the statis The reader is referred to Jenkins and tical model ~s to simulate present Watts (1968) for a detailed discussion conditions, it was desirable to locate a of spectral analysis of time ser~es. river station with similar conditions to The results of an analysis on the 50 Weber River are shown 1n Table 5 and 3.0 Figure 31. Another method of calculating the spectral density is to utilize the Fast Fourier Trans form (Canfield 1982). A program named FFT.FOR utilizing this > t- method is also found 1n Appendix C and 2.0 the results are shown in Table 6. OO Z WEBER RIVER AT W Since the spectral density can be o l'./ GATEWA'( calculated using either method, the I I choice is left to the user. The values «..J from the two methods are not exactly the a:: same. This is due to the method of t 1.0 smoothing the raw spectral density O (Jenkins and Watts 1968). W a. 00 From Figure 31 it can be seen that the spectral density of the present modified flows on the Weber River at Plain City is a reasonable estimate of that found at the Gateway Station and o.o~------.------. 1S therefore used in the remaining 0.00 0.25 0.50 analysis. FREQUENCY Table 5. Calculated spectral densities Figure 31. Comparisons between spectral for the Weber River for the density functions for the period 1921-1977. We ber River. Spectral Density Table 6. Spectral density for the Weber Frequency Modified Weber River at Gateway using Weber River River at FFT. FOR. at Gate~ay Plain City Frequency Spectral Density 0 2.71 0.00 2.10 2.90 0.03 3.47 0.04 2.46 2.92 0.07 2.20 0.07 1.97 2.03 0.10 1.04 0.11 1. 35 1. 27 0.13 1.71 0.14 1. 61 1.57 0.17 1. 51 0.18 1.43 1.40 0.20 1. 32 0.21 0.91 0.80 0.23 0.62 0.25 0.57 0.50 0.27 0.49 0.29 0.63 0.58 0.30 0.66 0.32 0.54 0.42 0.33 0.48 0.36 0.23 0.15 0.37 0.17 0.39 0.17 0.12 0.40 0.11 0.43 0.29 0.26 0.43 0.13 0.46 0.49 0.37 0.47 0.33 0.50 0.57 0.37 0.50 0.39 51 Once the spectral density is 5. Average recorded yearly flow. calcul ated a sequence of generated flows can be developed utilizing the 6. Previous year's flows which the program named GENSPEC as 1 isted 1n model uses as initial values. The model Appendix D. Details of the generation allows average monthly values to be used procedure can be found in Canfield and asks which option is desired during (1982). Since the result of generation execut ion. based on the spectral density is a normal distribution with zero mean and a The amount of data available limits standard deviation of one, the results the input for items 1, 3, and 4. must be modified. This is done by Numbers 1 and 3 can contain data corre mUltiplying each generated value by the lating present year's flows with one or sample standard deviation and then all of last year's flows. If all adding the mean. This is accompl ished of last year's flows are utilized the within the above mentioned program. matrix described in number 1 would be a 24 by 24. The maximum possible maxtrix For verification that generated and size for the Weber River at Gateway is observed inflows were statistically limited to 13 (N-l) since there exists similar, a series of 50 generated only 14 data points. The following sequences of 7 annual values each was discussion will be somewhat more general found to be N(0.02,1.03) as compared to in that it wi 11 be assumed that corre the theoretical N(O,l) distribution. lations can be made with last year's October, November, and December flows. Monthly Time Series Generation The concept is' then presented in theo retical form and the matrices can be Once yearly values have been expanded or contracted as required. obtained, some method must be used to disaggregate them into a proper distribution for further monthly Table 7 . Difference between monthly analysis. The method used herein is means and lagged monthly based upon natural flow character means. i s tic s d e r i v e d from the a v ail a b 1 e record. The disaggregation model (called MONGEN in Appendix E) requires Month a the following data inputs (Canfield Year January December December 1983) . 1968 7,095 7,913 7,337 1. Variance-covariance matrix 1969 14,656 8,362 7,913 between monthly data transformed 1970 8,735 6,734 8,362 to common logarithms. 1971 12,443 8,497 6,734 1972 12,488 4,394 8,497 2. Mean monthly streamflows. 1973 6,143 4,018 4,394 1974 7,631 2,949 4,018 3. The lagged monthly means for 1975 3,008 11,107 2,949 any of the previous .year's months which 1976 9,986 2,749 11,107 have a significant correlation with the 1977 2,226 2,768 2,749 present year's months. For an illustra 1978 2,630 3,800 2,768 tion note Table 7. For large data sets 1979 6,533 2,502 3,800 the difference will be negligible and 1980 7,743 3,539 2,502 the regul ar data mean value can be 1981 2,823 3,454 3,539 used. Means 7,240 5,199 5,476 4. Yearly total flows to be disaggregated. aData have been lagged one year. 52 The required vectors and matrices are: mean monthly flows ( ~IX*)~ = data vector (w) = 10'1l0* 0'111* 0'112* I , I 0'210* , , I , , I , , , I , Variance - , I Covariance Symmetrical , I Matrix from 10'1210* 0'1212* Data Set (Z~*) I~;:-0'10*1l* ~0~2: Transpose of upper I 2 right quadrant I 0'11* 0'11*12* I Symmetrical 2 I 0'12* 53 where: Now Ix = A[ll *AT which resu1 t s 1n a 16 x 16 matrix of the form Xi = mean monthly flow for month 1 'f.y 1 'f.yw Xi* = mean lagged monthly flow for (12x12) I (12x4) month i as illustrated in h = I Table 7 -----+--- 'f.ywT 1 'f.w Xi* = previous year's flow for 1 month 1 (4x12) 1 (4x4) T = this year's total flow 0i2 = variance of month i flows 0'1J • = covar1ance between months i and j = covariance between month i and previous year's month J 2 0i * = variance of previous year's From the above matrix a var1ance month i flows (for lar~e covar1ance matrix for the system can data sets this equals 0i ) be found by the equation: 0'* .*= covariance between previous 1 J year's i and j flows (2) If This is a 12 x 12 matrix and is used as input into the RNVR subroutine of the program MONGEN along with the mean vector 11~/w as calculated from Equation 3. then find [A] such that A ~ x * = 0 x (3) the A matrix is then 10 ------I where 010 1 -; 010 \ = vector of monthly means I 010 a's 1 111: 1 010 1 ll~ = mean w vector 1 010 1 1 010 1 all other terms are as presented 1n 1 010 1 the above discussion A 1 010 1 1 a's 010 I The results obtained from MONGEN I 010 1 are a series of iength N < the number of 1 010 1 data points which simulate the statis 1 010 1 tical characteristics of the series. 1 010 1 ____ ---01 Model ing resul t s are presented 1n the following section. 111111111111000 54 MODEL RESULTS Statistical Models as shown in Table 9. The results could be improved if more data points were Yearly Flow Generation available from which to obtain a better estimate of the true monthly statistics. The accuracy of the yearly genera tion program named GENSPEC listed The results presented herein ~re in Appendix D was checked by comparing also limited by the fact that the i:E.* the generated versus theoretical (ideal) matrix described in the preceding statistics as shown in Table 8. section was limited in size due to the lack of river data. Since the variance Upon generating a yearly sequence, covariance matrix is the means whereby the historical mean and standard devi the model simulates the correlation ation were used to convert the N(O,l) between monthly flows, its completeness distribution back into one with histori ~s important. In most natural systems cal statistics. This is accomplished by the dependence of the present months mUltiplying each generated value by the surface flow on'those of previous months standard deviation and then adding the will decay rapidly. Since the Weber mean. River ~s highly regul ated the char acteristics of management are also Monthly Flow Generation included within the monthly correla tions. Table 10 shows the correlation The monthly disaggregation program matrix for the January through December called MONGEN as listed in Appendix E flows for the Weber River at Gateway. converts yearly streamflow into monthly From Table 10 the general trend of streamflow according to the historical correlations ~s to decrease with time statistics at the Weber River Gateway for a few months then inc rease somewhat station. Disaggregated monthly flow before continuing a downward trend. statistics generated by MaNGEN were This lagged correlation increase might . compared to the monthly flow statistics very well be explained by management of the observed data and the results are practices on the river, however, its source ~s not confirmed nor studied further here. l'ab le 8.' Comparison between the theo ~. ret ical and generated means, From Table 10 it is also noted that standard deviations and skews correlations can be made between any two for GENSPEC.FOR. months of the present year. However, the complete variance-covariance matrix described ~n the preceding section Standard contains o,nly one column which corre Mean Deviation Skew lates each of the present years months with last years December flows. There fore January can only be correlated with Theoretical o 1 o the previous December which is a one month correlation. On the other hand Generated -0.0 1. 01 -0.04 this years December can be correlated with the previous years December giving 55 I. I. Table 9. Comparison between generated and observed monthly statistics (mean/standard deviation). Month Historical Values Run 1 Run 2 Run 3 Run 4 Run Avgs. Jan 7440/3968 7452/4258 8345/7338 7731/4494 8161/ 5809 7922/5475 Feb 8252/4496 8406/4947 8909/5452 9225/5220 9072/5648 8903/5317 Mar 18844/12031 18238/7950 20693/10211 20067/9372 19174/9334 19543/9217 Apr 30774/17430 30228/14730 33431/16617 32845/15147 30337/13028 31710/14880 May 47276/21478 48943/17959 43771/16593 46081/15800 46194/18595 46247/17237 Jun 33756/16742 35027/16640 33917/16554 32308/15577 33512/17167 33691/16485 Jul 17016/6016 16189/5778 16432/6343 16431/ 604 7 16568/6023 16405/6048 Aug 13957/2128 13338/4579 12938/4477 13267/4624 13608/4709 13288/4597 Sep 10725/2070 10321/3771 10114/3441 10281/3672 10717/4022 . 10358/3727 Oct 7210/2552 6827/3027 6790/3129 7021/2959 7316/3344 6989/3115 Nov 5092/2594 5285/2538 4691/2401 4991/2432 5270/2425 5059/2449 Dec 5199/2767 5038/2621 5261/4150 5042/2863 '\':th')/'lOOrl 'H76/3129 Table 10. Correlat ion between January through December Weber River flows at Gateway. \.Jl ~ Jan Feb Mar Apr May Jun Ju1 Aug Sep Oct Nov Feb 0.845 Mar 0.737 0.848 Apr 0.586 0.812 0.933 May 0.382 0.570 0.762 0.859 Jun 0.009 0.124 0.341 0.490 0.762 Jul 0.181 0.368 0.502 0.613 0.713 0.735 Aug 0.658 0.652 0.759 0.769 0.833 0.625 0.769 Sep 0.494 0.585 0.735 0.715 0.724 0.514 0.711 0.855 Oc t 0.470 0.610 0.634 0.638 0.623 0.579 0.760 0.770 0.715 Nov 0.357 0.395 0.517 0.485 0.660 0.636 0.769 0.774 0.604 0.848 Dec 0.236 0.163 0.248 0.257 0.401 0.614 0.759 0.634 0.423 0.756 0.849 a 12 month correlation. The inability there is a significant quantity of water to correlate this years monthly flows wasted each year to the Great Salt Lake. wi th the January through November fl ows A groundwater recharge simulation from the previous year is a noted discussed in the next section is based disadvantage. on the p rem i set hat wa t e r wo u 1 d be available for much of the year as is Available Flows shown in Table 11. Since the wasted water flow at Plain Ci ty also inc ludes Available river flow for recharge Ogden River water, care would have to purposes can be determined in two ways. be taken to ensure that the water right First, if t he total legal water right allocation was filled between the point for the Weber River between Gateway and of the recharge divers ion on the Weber the Great Salt Lake were determined, net River and the joining of the two nver available water could be found by systems. subtracting rights from river flows. This method is very campl ex due to the Since water rights along the Weber large number of water right holders River are so complex, and perhaps along the Weber River whose rights artificially high in terms of available vary according to time of year and water, a simplification was sought which climatologic conditions. It is further \oOuld be a more realistic estimate of complicated by the fact that the court actual water use. Water use estimates decreed legal right is often not used to are broken into two parts. The first is its fullest extent. In some cases for the normal withdrawal of water by quantities may be based upon the carry small users as administered by the Weber ~ng capacity of the ditch, canal, River commissioner and the second is the pump, or pipe and may not be truly average withdrawal of water for Willard representat ive of the ac tual water Bay to be used for subsequent pumping used. and distribution by the Weber Basin Water Conservancy District. Since The second method involves deter a clear and consistent withdrawal mining the quantity of water being pattern for Willard Bay does not exist, wast ed into the Great Salt Lake. This three values for total withdrawal can be accomplished by either a direct will be used for each month as shown in measurement of the flows as they enter Table 12. The first value includes" the the lake or by subtracting the water Willard Bay calculated mean plus one rights of downstream users after the standard deviation flow, the second its Weber River passes· the Pl ain ci ty gaging calculated mean, and the third its Station. The number of users downstream calculated mean m~nus one standard of said station are few and the task deviation. For recharge purposes these would be much simpler than using three values approximately represent the legal water rights. This method drought, normal, and flood conditions, would appear to allow more recharge respectively. input because it would be a measure of actual use rather than legal right. Computer"input values for available recharge water were obtained by sub Estimates for the average wasted tracting the values shown in Table 12 water entering the Great Salt Lake were from the series of monthly streamflows obtained by subtracting the water right generated by the statistical models held by the Ogden Bay Bird Refuge from previously mentioned. the 21 year average river flows near Plain City. The values shown in Table Groundwater Model 11 do not include the few water right holders downstream of the Plain City In order to forecast the results of gaging station, but they do show that any action through the use of a computer 57 Table 11. Average wasted Weber River flows into the Great Salt Lake (1956-1977). Month Average Monthly Ogden Bay Refuge Average Wasted Flow Flow (cfs) Right (cfs) cfs Ac re-feet7mont h Jan 307 20 287 17,647 Feb 376 20 356 14,218 Mar 622 50 572 35,171 Apr 878 135 743 44,212 May 1060 135 925 56,876 Jun 576 135 441 20,241 Jul 101 80 21 1,291 Aug 65 80 0 0 Sep 135 80 55 3,273 Oct 237 150 87 5,349 Nov 275 150 125 7,438 Dec 288 150 138 8,485 model, the following three main steps If man's influence on the flows cont1nue must be successfully completed: to change throughout the period of record, it may be impossible to deter 1. Steady state calibration mine an initial steady state condition. 2. Transient calibration In such a case an initial starting 3. Verification condition must be assumed based on the historical sequence of events and their Steady State Calibration effect on the system. One common problem encountered in Recorded wa ter we 11 1 eve 1 data for model calibration is the selection of a the Weber Delta area began in the late period of time during which conditions 1930s. From these data two types of do not change. In natural systems this contour maps were prepared. is often difficult because of the many sources of recharge and discharge all of The first type 1S presented 1n which are seldom constant. Figures 7-13 as piezometric contour maps for the period 1937 through 1980. In the Weber Delta area the Weber The second type is shown in Figures River is a direct source of recharge 14 and 15. Figure 15 illustrates the which varies continuously with time. change in position of the 4280-ft Sequent ial periods of time which have contour line with time. Figure 14 the same distributions and quantities of in a similar fashion compares the recharge seldom occur. Ot her recharge changes made by the 4300-ft contour sources such as mountain front recharge over the same time interval. Com are more constant than the river re parison of these figures indicate charge. These sources, however, can that the early period of history be also vary in sufficient amounts to make tween 1937 and 1945 appears to be an the selection of a period of steady adequate starting point for a steady state conditions difficult. state calibration. Figure 28 also suggests that early pumping rates Man's activities also influence the were quite constant prior to 1956 Occurrence of steady state conditions. showing that the early recorded history 58 Table 12. Monthly estimates for utilized Weber River water rights (ac-ft). Jan Feb Mar Apr May Jun Ju1 Aug Sep Oct Nov Dec Mean plus 15827 15926 28773 42998 81122 58794 39393 38262 38152 41280 1662 7172 one standard devi ation Mean 9025 8465 16893 25407 63165 45696 37163 36547 36586 37804 646 3418 Mean minus 2223 1004 5013 7816 45208 36000 36000 36000 36000 36000 0 0 one standard deviation Ln 1.0 would be suitable for a steady state the distributions of K'/B' and S are analysis. shown in Figures 33 and 34 respectively. Values of flow (Q) include both recharge The equation of groundwater motion and discharge. The final calibrated presented in the preceding section 1S recharge from the mountain front was found to be equal to 24,200 ac-ft (2,904 ha-m) per ye ar. St ream recharge wa s sah = ~ T ah) +~ T ah) estimated to be 7.8 percent of the river at ax ( xx ax ay ( yy ay flow (Feth et al. 1966) and deep sub surface recharge along the western K' borders of the project area was found to (h - h) • (1) + Q + B' a be approximately 19,500 ac-ft (2,340 ha-m) per year. The methodology used to calibrate Under steady state conditions this the model was to make comparisons equation reduces to: between contour maps developed from well data and those derived from the com a put e r • Th i s c om par i son was mad e b y a (T ah) + T ah) ax xx ax ay ( yy ay making a visual scan for overall fit rather than a numerical optimization routine. Figure 35 compares the final K' calibrated contours to the assumed 1937 + + (h - h) 0 . (4) Q B' a = contours. Transient Calibration The geologic characteristics on The trans ient cal ibrat ion process which Equation 4 depends are Txx, Tyy, was continued over the time interval and K'/B'. The dependent hydrolog1c from 1940 to 1970. From Equation 1 the characteristics for steady state addition variable to be calibrated 1S calibration are Q and ha . This means the storativity (S). It is also possi that during the initial calibration ble to improve some of the previously phase the values of Txx, Tyy , K'/B', calibrated variables somewhat during Q, and ha must be either 1nitially transient calibration. It was found in defined or determined through the this model for example that localized calibration pr<;>cess. The only known changes in K did little to affect the variable of those mentioned above are steady state solution. the values of the heads in the adjacent aquifer (ha ). By assuming that Txx Some int eres t ing phenomena we re is equal to Tyy the number of variables observed during this transient calibra is reduced by one. The hydraulic tion phase. Perhaps the most important conductivity of the medium and the of these is that mountain front recharge saturated thickness are entered into the has apparently decreased dramatically program which then calculates T. The over the past 40 years. During calibra remaining variables were found through tion it was impossible to achieve the the calibration process. Initial measured drawdown throughout the region estimates of recharge, hyd raul ic con without either increasing pumpage or ductivity and K'/B' were obtained from decreasing recharge. Since records or Feth et al. (1966), along with un reasonable estimates of pumpage can published data provided by the United be obtained it was decided that the States Bureau of Reclamation. Figure 32 decrease in water levels was due more to shows the calibrated areal distribution recharge decreases than pumping in of permeability in feet per year, and creases. Well B-5-l-36bbb was utilized 60 Figure 32. Calibrated permeability distribution in ft/yr. Note' Storage coeficienl (Sy) for the shaded region was equal to 0.01. Figure 33. Calibrated K'/B' distribution Figure 34. Distribution of calibrated in l/yr. specific yield and stora tivity coefficients. 61 to confirm this point.' This well was again from 1966 to 1968. The sparse installed as an observation well in 1952 data between 1961 and 1966 and beyond by the Bureau of Reclamation and is 1968 made it desirable to correlate the located within one-half mile of the well fluctuations with those of another mountain front. Since there are no well to lengthen the record. By so pumping centers near this well, any lengthening the record and observing the d rawd own woul d be rna inl y caused by variation in well water levels over the fluctuations in mountain front recharge. period of record, a change in mountain front recharge might be detected. The Well B-5-l-36bbb was continuously regression of well 36bbb with B-4-l- recorded from 1953 to 1961 and then 30bba ~s shown in Figure 36. Water R3W R2W RIW Z N LEG END -- ASSUMED --- CALIBRATED Scale 3~1M;S:S§~§SSS:1F=~F;S:SS\;S:SW~'S\~o=====:::::::),3 miles Figure 35. Calibrated and assumed 1937 contour lines. 62 levels were then compared for the (HAFB) should be in the order of 78,000 regressed and historical we 11 and are gpd/ft (969 m3 /m·d). Within 1 mile shown in Figure 37. to the north this value increases to 508,000 gpd/ft (6310 m3 /m·d) and During calibration it was found within 2 miles to the east it is as high that decreases in recharge had to be as 1,186,500 gpd/ft (14,740 m3 /m·d). made at times which were closely related Because of partial penetration effects to the decreases observed in well and the uncertain aquifer thicknesses B-5-l-36bbb (see Figure 37). The sudden the values of the true hydraul ic con drop of approximately 40 feet over a 1 ductivity K are unknown but the ratios year period in this we 11 was confirmed should be similar. by examining the cont inuous recording from the well. During the initial steady state calibration runs the model did not The transient cal ibration process indicate that local variations in also helped clarify and refine Some of hydraulic conductivity around HAFB were the geologic characterist ics of the present. This however required a It er area. For example there exists a at ion during the transient calibration corridor of highly transmissive material because it was found that the modeled which extends westward from the mouth of conductivity values were so high that no the Weber Canyo n. Unpub 1 i shed da ta localized drawdown developed 1n later obtained from the Bureau of Reclamation years as shown in Figures 11 and 12. contain well tests which indicate that The final calibrated values for hydrau the transmissivity of the Delta Aquifer lic conductivity were shown previously in the region of Hill Air Force Base in Figure 32. 10 4320 -en • w c 0 • Z 4310 • -a ..Q ..Q 4300 0 rt) I -I V 4290 I m • outlier ..J ..J 4280 IJJ 3= z c 4270 « 4270 4310 4350 4390 UJ ::z:: HEAD IN WELL B-5-1-36bbb (NODE 10) Figure 36. Regression of well B-5-l-36bbb (node 10) versus well B-4-l-30bba (node 95). 63 since AQUIFEM-l is a two-dimensional for the years 1940, 1945, 1955, 1964, model, provision must be made to manual and 1970 and are shown in Figures 50 ly adjust the adjacent aquifer heads. through 54 respectively. The actual This became a problem during transient location of the piezometric surface in calibration because little data exist Township 5 north, Range 1 west is over much of the time span involved, un c e r t a in due I a c k 0 fda t a in t his especially in later years. The varia region. tion of adjacent heads may have a signific ant impact upon the response of Verification the model. This problem was solved by continuing the recorded trend of the Verification of the calibrated adjacent aquifer heads through the model covered from 1970 to 1981. It was period of sparse data. started in 1970 because the model was Figures 38 to 48 compare simulated already calibrated to that year and it ve r sus his tor i cal h yd r 0 g rap h s for was a simple procedure to extend the selected wells. All hydrographs plotted record from that initial point. During use a third order cubic spline interpo verification it was found unnecessary to lation. Figure 49 shows the relative change the values of mountain front or location of each node presented. deep recharge from their base values Comparisons between the assumed and reached in 1963. This agrees with the simulated piezometric contours were made simulated hydrograph for well B-5-l- 4390 +- -~ I 4370 : , 0 , , C +- r I Q) I I - , I -W Q) , ______...L , (!) ~ --, 4350 " I 20,000 a:. Q ' \.... I I « « ::I: UJ U J: ,., ~l W 4330 I ~, ..... 15,000 a; -, ...... _~I" \ \ ... ~'I U '-' , r- a:: \ Z r- 4310 u. 0 w Il 10,000 a:. ~ \ I LL 0 N z W 4290 5,000 'bT" --- Mountain front recharge ~ -Q.. \ I~\ Z -- Recorded well \ I \ \J " :::> - --- Regressed well 0 4270 0 ~ 1940 1950 1960 1970 YEAR Figure 37. Comparisons between unaltered and regressed well B-5-l-36bbb (node 10) and mountain front recharge. 64 4390 4390 4340 4340 li i 4330 ~ 4370 4370 ::. :! ! 4330 0 ~ 0 <:( ~ W <:( 4320 w I W :r ~ 4350 43SO u :r 4320 l.? U a: u .... 4310 fE ~ w ....a: w ~ 4330 4330 ::;: w 4310 ::;: ::;: 0 o 2 0 4300 N N N !,!J W , ~ w 4300 a. Q: 4310 4310 0 \.:~---1 Q: 0 w 4290 ..J \... ,'/,...... , ...... :: ;:l w § Ii ::;) ..J 4290 ~ - AC1uoI R_dod Hydro;ropll I- ~ 4290 4290 i 4280 - Actuol Rec::orded HydrOgfOph ::;: ..... " SlmulotK HydroOroph ~ .. Slm~loted Hydrooraph U; 4280 (i'j 4270~-----r------~-----r------~----~--:---+ 4270 4270 1940 1945 1950 1955 1960 1965 1970 1940 1945 1950 1955 1960 1965 1970 YEAR YEAR Figure 38. 1940-1970 simulated vs. Figure 39. 1940-1970 simulated vs. historical hydrographs for historical hydrographs for well B-5-l-37bbb (node we lIB - 5 -1 - 3 3 c d a ( nod e 10). 62). 4320 4320 4330 Q; 4330 Q; Oi., :! ~ .:;.. 4310 4320 0 4310 ~ ~ <:( 0 0 <:( I <:( 4320 ~ W w I "",,,,~,,, u :r u 4300 a: l.? 4300 ~ Sol 4310 l- a:: w W I- 4310 W ::;: fE ::;; :::;: w 0 2 :::;: N 0 0 W N 4290 4290 ~ N 4300 !,!J w a:: a. 0 4300 0 W a:: W ..J ..J <:( Ii <:( Ii ..J i? 4280 4280 :5 i? 4290 ::> - ""tual Rt<:O 4320 4320 4300 4320 Q; 4310 ] ~ 4310 Q; 4295 J'! ~ 4315 - Cl :! 0 0 <:( 0 <:( L5 4300 4300 ~ <:( w W 4290 :r I I 4310 Sol U U U a: 4290 4290 fE a: I- W a: l- w :::;: !;j 4285 W ::;: 0 ::;: 4305 ~ 4280 4290 [j 0 N 2 N W w Q: w 4280 a: a:: 0 a:: 4300 0 ..J 4270 4270 W ..J W <:( <:( ::;) Ii ::;) Ii I- ..J I- - Aduol Recorded Hydrooroph 4275 - Actual ReCOl'ded Hydrooroph 4295 ~ 4260 4260 :5 $imulQfed Hydrograpn i ~ .- Simuloted Hydrooroph ::;: (i'j u; 4240 4240 4270 1940 1945 1950 195!! 1960 1965 1970 1940 11945 1950 1955 1960 1965 1970 YEAR YEAR Figure 42. 1940-1970 simulated vs. Figure 43. 1940-1970 simulated vs. historical hydrographs for historical hydrographs for we lIB - 6 ':"" 1 - 3 0 c c a ( nod e well B-5-2-33ddc (node 104). 129). 65 4310 4300 4300 Q; 4310 Q; Q; ~ ~ 4290 4290 ~ Cl ...... oCt Cl Cl UJ oCt ...... :I: UJ .' LiS :I: u :I: 4280 4280 4300 a:: u u f- a:: a: \ f- UJ f- \ :;; UJ \ UJ 0 :;; 4270 4270 ::;; N 0 0 UJ N N 4290 a: !!! UJ Q. Cl 4260 4260 ~ UJ ..J oCt UJ ~ :::l ..J f- ~ 4280 :::l ...J -- Ac1ua1 Recorded HydFOQ'dp/l :;; 4250 - Actual Recorded Hydro9roph 4250 ::J ..... Simulated Hydrooroph ~ ..... Simulated Hydroqroph :;; .. Cii ij) 427~~+-0-----1~~-5------19~~------1~~-5-----1~96~0------~----~ 4240 4240 1965 1970 1940 1945 1950 1955 1960 1965 1970 YEAR YEAR Figure 44. 1940-1970 simulated vs. Figure 45. 1940-1970 simulated vs. historical hydrographs for historical hydrographs for well B-5-2-4ddc (node well B-4-2-20ada (node 133). l38) . 4300 4300 4290 4290 Qj Q; .2! Qj 4285 .2! .... 4285 ~ .'. '. Cl ~ 4290 4280 oCt 4290 ~ Cl .. ' UJ UJ ...... :I: « 4280 :I: :I: ~ UJ :I: . ' .... ~ U 4275 U U a:: U a: f- 4275 f- UJ a: w ~ f- ---~ ::;; ~ 4280 4280 :;; UJ 4270 ::;; 0 2 .. 4270 N 2 UJ 0 UJ UJ N a: UJ 4265 a: a: Cl a:: 4265 Cl UJ UJ ..J 4260+-----__------~------~---- __------~------+ 4260 4250 1940 1945 1950 1955 1960 1965 1970 1940. I~ 1950 1955 1960 1965 1970 YEAR YEAR Figure 46. 1940-1970 simulated vs. Figure 47. 1940-1970 simulated vs. historical hydrographs for historical hydrographs for well B-4-2-8dcc (node well B-5-3-13ddc (node 139 ). 152). 4290 4290 Q; Q; 4280 ~ OJ Cl ~ 4280 « Cl UJ « :I: UJ :I: 4270 U U 4270 ~ il: UJ f- ::;; UJ 0 ::;; 4260 N UJ 24260 UJ a:: Cl a: UJ 4250 ...J ~ 4250 ...J :3 ::J - Actual Recorded HydrQ9roph ;; ~ " .... Simuto1ed HydroQroph (f) 4275 4240+-----____----~------~------~---- __----~ 1940 1945 19~ 1955 1960 1965 1970 YEAR Figure 48. 1940-1970 simulated vs historical hydrographs for we 11 B - 5 - 3 -1 5 d d a ( nod e 161) . 66 36bbb shown in Figure 37 in that the of assumed and simulated piezometric well level remains low after its down contours for the years 1974 and 1980 as ward trend which occurred during the shown in Figures 66 and 67 respectively. 1960s. If this well is an indication of mountain front recharge it indicates Sensitivity Analysis that recharge has remained at a low 1 eve 1 sine e 1 963 . Th eon1 y c hang e The computer model was checked for necessary was to adjust the heads in the sensitivity to alterations in the values adjacent aquifer so as to simulate their of conductivity, storativity, and continued decline. confining layer permeability divided by its thickness for three nodal locations. The results of verification pre The three nodes along with the adjacent sented in hydrograph form can be elements which were altered are shown in found in Figures 55 through 65 with the Figure 68. Sensitivity runs were made relative locations of each node shown in by holding all variables constant Figure 49. Comparisons were also made except one. The changing variable was Figure 49. Nodes used for comparison of simulated vs. historical well response during calibration and verification. 67 R3W R2W RIW N LEGEND -- .ASSUMED -- - CALIBRATED Scale 3~1&:SS:\\SlS.'Sw~·1====!"Ir:S:SS\\s.:s!SS>l!i)"8F====~~ miles Figure 50. Comparison between assumed and simulated piezometric contours for 1940. 68 R3W R2W RIW z cD I- I z It) 0 l- t() q- ~ \ ~/- ~ ~/- (-<;: ~ z q- l- N LEGEND ASSUMED --- CALIBRATED Scale 3~iM~"S~,sI'l.'!1F=r~SS>:;l;SS~\SS~'8======l3 mi I es Figure 51. Comparison between assumed and simulated piezometric contours for 1945. 69 R3W R2W RIW z, CD ...... 1- ..... " z \C) I- Z <:t I- N LEGEND -- ASSUMED - -- CALIBRATED Scale 3~6SS:S:S:§Sss:!ss~1;=~r:s:s:,ssss:!SS>l>Ssss5.!=8=====:::;3 miles Figure 52. Comparison between as·sumed and simulated piezometric contours for 1955. 70 R3W R2W RIW Z <:t I- LEGEND -- ASSUMED -- - CALIBRATED Scale 3~1§>~§s>s:ssss!>l!1==Fs:5lSSSi.'§"'~'8======:::::;~ mi les Figure 53. Comparison between assumed and simulated piezometric contours for 1964. 71 R3W R2W RIW ~ ~.). ~<',>. \ <~ \ ~ \ z v LEGEND l- N ASSUMED CALIBRATED Scale ~f~§~§s~1f===!f~ss~§s~*~8=====::;3 miles Figure 54. Comparison between assumed and simulated piezometric contours for 1970. 72 4300 --Q) ~ - 4300 - -~ 4295 •••••••••••••••• ° 0 o « -o .' w « 4295 I ~ 4290 ...... U 0:: U I 0:: W \\ 4290 :2: ~ 4285 \\ o :2: N o \\ W N a. W 4285 a. 4280 \: r~ / o \:. . I:' ....\ / w .-I t:t § \\ / .... \ .. ) 4280 .-I ~ I- 4275 - Actual Recorded Hydrograph \\ /: .. ...:/ :2: ~ ...... Simulated Hydrograph 0.: (j) ~. :0 '.. 4275 4270+---~----~---r----r----r--~----~---+·~··---.----.---~ 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 55. 1970-1981 s imul ated vs. historic al hyd rographs for well B-5-1-33baa (node 63). 4300 4300 -Q) -Q) -Q) -Q) 4295 4295 - - «0 0 w « I W I 4290 4290 U 0:: U I- 0:: W I- :2: W 4285 4285 0 :2: N 0 '. ~.\ w N r a. uJ / \.. 4280 0 a. 4280 : t \". w ; \ .... .-I ;.: « : t:t ~ .-I I- 4275 4275 ~ U - Actual Recorded Hydrograph .' :2: « ...... Simulated Hydrograph (j) 4270 4270 19701971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 56. 1970-19'81 simulated vs. historical hydrographs for well B-4-1-16bdd (node 72). 73 . 4300 4295 Q) -Q) - '. -$ 4295 '. . -0 ...... ::> ~ 4275 - Actual Recorded Hydrograph :;E ~ •••••• Simulated Hydrograph ...... 4270 (J) 4270+----r----~--~--~----~--~--~----._--_r--~--__; 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 57. 1970-1981 simulated VS. historical hydrographs for well B-4-l-7baa (node 86). 4300 4300 -Q) .!- -Q) .. , - 4295 .. , 4295 0 ~ - .. .' ::> ~ 4275 - Actual Recorded Hydrograph 4275 :;E •...•• Simulated Hydrograph ". (f) ~ .. " 4270 4270 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 58. 1970-1981 s imu1 ated vs. historical hyd rographs for well B-S-1-18abb (node 90). 74 4295 4295 --Q) - Q) ~- 4290 4290 - «0 0 w « J: W 4285 4285 U I a:: U . ~ a: .... - W ~ :E W 4280 4280 0 ~ N 0 W N a.. W 4275 4275 0 a.. W «....J ~ ::> ....J ~ 4270 4270 :::> U - Actual Recarded Hydragraph ~ « •••..• Simulated Hydragraph (f) 4265 4265 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 59. 1970-1981 simulated vs. historical hydrographs for well B-4-1-30bba (node 95). 4290 4290 --Q) 4285 ~ -Q) -Q) 4285 -0 « -Q W « 4280 J: W ...... J: 4280 .. ' U .' ' ...... cr ~ ". ~ a: 4275 W ~ :;E W 4275 0 ~ N 0 W N 4270 a.. W .. ' 4270 0 a.. W ....J ~ « '. .... 4265 ...J :::> :::> u~ 4265 - Actual Recarded Hydrograph ::2: « ..••.. Simulated Hydrograph (f) 4260 4260 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 60. 1970-1981 simulated vs. historical hydrographs for well B-4-2-20aaa (node 115). 75 4285 4285 - <1> -QJ <1> ••• ~ •• o • .... -QJ 4280 4280 '. -£:) 4255 4255 1970 1971 1972 1973 1974 1975 1976 977 1978 1979 1980 1981 YEAR Figure 61. 1970-1981 simulated vs. historical hydrographs for well B-S-2-33ddc (node 129). 4300 4300 -<1> -- -<1> ~- 4295 ~ 4295 £:) 4270 4270 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 62. 1970-1981 simulated vs. historical hydrographs for we 11 B-S-2-16dcd (node 131). 76 4275 4275 - Q) -Q) -Q) ~ 4270 4270 -0 ...... 4245 4245 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 198\ YEAR Figure 63. 1970-1981 simulated vs. historical hydrographs for well B-4-2-20ada (node 138). 4265 -Q) -Q) -Q) -Q) 4255 4260 -0 « -0 ...... , w « .. , :z: w .' :z: 4250 4255 U 0:: U t- o:: ...... w ~ 4250 ~ W 4245 0 ~ N 0 W N a.. W 4240 4245 0 a.. u..J ....J ~ -l 3 4240 ::::> ~ 4235 - Actual Recorded Hydrograph ~ ~ ...... Simulated Hydrograph CJ) 4235 4230 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 198\ YEAR Figure 64. 1970-1981 simulated vs. historical hydrographs for wl'!ll B-5-3-12add (node 153). 77 ..- 4265 - 1970 1971 1972 1973 1974 1975 1916 1977 1978 1979 1980 1981 YEAR Figure 65. 1970-1981 s imu1 ated vs. historical hydrographs for we 11 B-5-3-15dda (node 161). R3W R2W . RIW z I-'" ~ <'..... ~i L~:," t- ASSUMED --- CALIBRATED Scale Figure 66. Comparison between assumed and simulated piezometric contours for 1974. 78 R3W RZW RIW Figure 67. Comparison between assumed and simulated piezometric contours for 1980. R3W R2W RIW T6N T5N T4N ---,------~--t 5 .. ;:1. c.:.~:.~:_:..:...::_~ __-_~ .:._-===:2 ~ Z!"; ~ m Iv Figure 68. Central nodes and surrounding elements used 1n the sensitivity analysis. 79 tested at 50, 75, 125, and 150 percent During the prediction phase of of its calibrated value and the results the study various quantities of recharge are shown in Figures 69, 70, and 71 for were tested for their impact on the nodes 86, 90, and 131 respectively. piezometric surface. Initial runs Figures for storativity are not shown included a maX1mum allowable recharge because little variation occurred over rate equal to 1350 ac-ft per month. the range tested. From the figures This value is based on the same recharge ment ioned it is seen that alterations rate and pit size as obtained from and in the aquifer characteristics over the used by the Bureau of Reclamation during range specified produce only minor its tests in the mid 1950s. Each effects upon the hydraulic response of recharge rate is discussed below in the aquifer at anyone of the three terms of its effect on the piezometric nodes. surface and the economic benefit gained by the reduced pumping lift. Recharge Simulation Runs Three prediction runs based on Artificial groundwater recharge can available water at Gateway according be managed in two basic ways. Fi rs t a to Table 12 were made for a maX1mum constant fl ow c an be recharged over a allowable recharge of 1350 acre-feet long period of time which will attempt per month. Each of these runs were then to keep the piezometric surface at a compared to a simulation run without higher level throughout time. The artificial recharge for 11 nodal points. second management technique is to Six of the 11 nodes are shown in Figures recharge only during specific time 72 through 77. The remaining five nodes intervals. This method attempts to were located further away from the recharge water into the system so as to recharge source and showed little provide the greatest benefit at a variation between runs. specific time of the year so as to alleviate a specific problem. If a region has 1 ight pumping demands over The economic benefit for any given much of the year but does contain an month is calculated by an areal integra interval of heavy pumping the second tion of reduced pumping lifts and method might be more appropriate. The pumping rates. It is important to note aquifer can be recharged just before the that the only economic benefits con heavy pumping period thus decreasing sidered 1n this analysis are those the pumping lift at the time relief is associated with reduced pumping costs. most needed. The program named ENERGY. FOR 1 isted in Appendix F calculates an average reduc The method of recharge also depends tion in pumping lift for each element, on whether or not the obj ect ive is to then uses the pumping rate and cost prevent large pumping declines at of energy to c alcul ate energy s aV1ngs selected locations or to 1ncrease the for that element. A cost of power equal entire water tab Ie. Since the system to 7 cents per kilowatt hour was used response in this case is so rapid, the throughout the analyses herein. The short term pumping declines could be process 1S continued until the entire eliminated quite easily if water were savings are summed up over the finite available just prior to and during the element grid. The economic benefit from maximum demand periods. On the other a maximum recharge rate equal to 1350 hand if the desired result is to in ac-ft/month wi th fl ood recharge condi crease the entire piezometric surface tions is approximately $2250 per year. then recharge should be continued on a By repeat ing the same process for a more continuous basis since the system maximum recharge rate equal to 2700 response is so rapid that gains are, acre-feet/month the economic benefit was quickly lost when recharge 1S stopped. found to be $4480 per year. 80 4300~------~ 4290 Cl ~ 4280 I 4270 - .50K ...•..75 K -- 1.25 K -'- 1.50 K 4260+---~----~--~----~--~----~--~--~----,----,--~ 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR 4305.------, 4295 Cl <{ W I 4285 .50 (K'/B'lo .75 (K'/B'lo 1.25 (K'/B'lo 1.50 (KI/B'IO 4275+---~----~--~----r_--_r----~--~--~----,_--_,--__4 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 69. Sensitivity plots for node 86 •. 81 4305~------~ 4295 Q ~ 4285 ::I: 4275 .75K 1.25K 1.50K 4265~--~----'---~----~--~----~--~----r----r----r---~ 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR 4310.------. 4300 Q l~· . « i:' \~ /: w .:~ r· ::I: I...... \\ ~.: '.'\".\' .1'.'{ ... ~/:. ".. " 4290 .50(K'/B'lo .75 (K'/B'lo 1.25 (K'/B'lo 1.50(K'/B'lo 4280+---~----~--~----~--_r----r_--_r--_,r_--_r----r_--~ 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 70. Sensitivity plots for node 90. 82 4295T------~ 4285 ~'-'~' Cl ~ 4275 :r: 4265 .25 K .75 K 1.25 K 1.50 K 4255~--~----~--~--_T----~--~--~----~--~--~--~ 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR 4295~------~ 4285 Cl ~ 4275 :r: 4265 .50(K'fB'lo .75 (K' f B'lo 1.25 (K'f B'lo 1.50 (K'f B' lo 4255+---~----~--~--~----r_--_r--~----~--~--~--~ 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 YEAR Figure 71. Sensitivity plots for node 131. 83 4330~------~ _ 4325 Q) -Q) - -c {i ~ 4320 I~ ::c U I~ 0: ~ ~ 4315 r ~ l \\ 1\\. ~. \~ 2 ~,,\\... \ \. I" ~. w ". \ . ' .. \ .( -.."';:. a:: 4310 No Recharge conditions Recharge based on available drought flows Recharge based on available average flows Recharge based on available flood flows 4305+------~------~------~------~------~ o 12 24 36 48 60 MONTHS Figure 72. Recharge hydrograph comparisons for node 63 with a rnaXl.mum recharge rate of 1350 ac-ft per month. 4315~------~------~ -Q) -Q) -c «w ::c u 4310 r0: W ~ 0 N W a. No Recharge conditions Recharge based on available drought flows Recharge based on available average flows Recharge based on available flood flows 4305+------~~------,------~------,------~ o 12 24 36 48 60 MONTHS Figure 73. Recharge hyd rograph comparisons for node 72 wi th a maXl.mum recharge rate of 1350 ac-ft per month. 84 4315~------~ - J! 4310 -CI <2: LLJ :::I: U a:r LLJ o~ 430 N LLJ a.. No Recharge conditions Recharge based on available drought flows Recharge based on available average flows 430~ ______~R~ec~h~a~rg~e~b~a~s~e~d~on~av~a~iI~aTbl~e~f~lo~od~fl~ow~s~ __~ ______~ ______~ o 12 24 36 48 60 MONTHS Figure 74. Recharge hydrograph comparisons for node 86 with a maX1mum recharge rate of 1350 ac"-ft per month. 4320?------~ -Q) -Q) !t:. 4315 CI <2: LLJ :::I: U a:r LLJ ~ 4310 N LLJ a::: No Recharqe conditions Recharge based on available drought flows Recharge based on available average flows Recharge based on available flood flows 430D+------~------~------~------,r------~ o 12 24 36 48 60 MONTHS Figure 75. Recharge hydrograph comparisons for node 90 with a maX1mum recharge rate of 1350 ac-ft per month. 85 4290~------ Cl <{ W ::J: ~. U 4385 a:: I W o:E N W 0::. No Recharge conditions Recharge based on available drought flows Recharge based on available average flows Recharge based on available flood .flows 4280+------,r------r--~----~------.------~ o 12 24 36 48 60 MONTHS Figure 76. Recharge hyd rograph comparisons for node 129 with a maX1mum recharge rate of 1350 ac-ft per month. 4290.---~------_r------_, --Q) ~ -Cl <{ W ::J: U 4385 w~ :Eo N W Cl. No Recharge conditions Recharge based on available drought flows Recharge based on available average flows Recharge based on available flood flows 4280,4------r~~~~~~~~~--~------.------~ o 12 24 36 48 60 MONTHS Figure 77. Recharge hydrograph comparisons for node 131 with a maximum recharge rate of 1350 ac-ft per month. 86 I , Table 13. Maximum available water at Gateway and Plain City (ac-ft/mo). Month J F M A M J J A S 0 N D Total Second year simulated 5084 3756 7374 14748 2794 13007 0 0 0 0 2611 3572 52,946 Gateway available flows Wasted flows at Plain 17633 14198 35129 44197 56838 26198 1282 0 3252 5359 7420 8473 219,978 City CP -.J Table 14. Hypothetical quantities and distribution of recharge for extreme recharge conditions. Month J F M A M . J J A S o N D Quantity (ac-ft) 61908 61900 61900 61900 61900 61900 o o o o 61900 61900 Since the calcul ated savings for of cost savings per year total $13,380 the previous runs are so small, atten and $51,150 for the Gateway and Plain tion was turned to the effect that could City runs respectively. be produced if all of the excess water were utilized. Table 13 includes monthly values for excess water calcu To check the effect a large quan lated from simulated flood water right tity of recharge water would have upon conditions at Gateway and from the the system, a simulation was made based wasted water at Plain City. on the quantities and distribution of recharge as shown in Tab 1 e 14. The Fi~ures 78 through 80 compare Table maximum rise in piezometric head at node 13 recharge simulations and the simula 90 equaled ISO feet and the cost savings tion run without recharge for nodes 86, due to reduced pumping lifts totaled 90, and 153 respectively. Calculations approximately $97,500 per year. 4380~------~ 1\ ,\ I'~ j\ I'~ t \ \ \ Recharge ba .. d o~l \ I \ :~er:I~~n W~~';d I fiT I \ 4360 i \ { \ o 4300i+------~------~------~~~~~----~------~ o 12 24 36 48 60 MONTHS Figure 78. Recharge hydrograph comparisons for node 86 utilizing all available water at Gateway and Plain City. 88 4420~------~ I\ . ,(\ ,\ :~c~~~~~9=a::~tfJ\ \ . \ I ' j \ flows at Plain City \ I \ - I . -: 4390 I \ ,\ I r II II ~ o { . \ \' I '\ « I \ \ LaJ I \ I· I' :J: I \ (\ I !\ \ I \ / \ 4360 ~ 0:: I \ I \ i /\ \ i \ I \ I 'J \ LaJ o~ ) \ l! \ \ )., \ J \ N /1 \ LaJ ;\ \. J ! / \ \ ( ! \ \ f /\ \ a:: 4330 (\ \... 1" \ \ ...1:' \.-.-i ; \ .j j \ / \ /-... / \ I \ I \ .I' \ I \ I \ I \ I " \ \ I \ I ,,'" " \. I \ ,/ '-', .... _'" ".... "'J1 \ , __, / available flood No recharge conditions 4300~------~------~------~~~~~--~~------~ o 12 24 36 48 60 MONTHS Figure 79. Recharge hydrograph comparisons for node 90' utilizing all available water at Gateway and Plain City. 4240.------~ Recharge ba.ed on overage wasted f -G) . \ -G) I' le . \ / . / . \ «o .j \ LaJ ,/'\ \ :J: ",," \ u 4235 a:: I LaJ o~ N LaJa:: 4230~------~------~------~------~~------~ o 12 24 36 48 60 MONTHS Figure 80. Recharge hyd rograph comparisons for node 153 utilizing all availab Ie water at Gateway and Plain City. 89 INSTITUTIONAL AND ECONOMIC CONSIDERATIONS Water Resources Management goverrnnent, have trans ferred and other wise affected these rights. Appl ica Numerous organizations, both public tions for additional water rights have and private, are involved in the manage been filed since the court dec rees, and ment and use of waters of the Weber and some of these are still pending before Ogden Rivers. Haws (1973) indicates the State Engineer. that there are 63 mutual irrigation companies, 4 water improvement dis Distribution of water according tricts, 12 municipalities, and 2 water to water rights on these r1vers 1S conservation districts in Weber County; administered by river commissioners not to mention a number of private water appointed by the State Engineer. companies which provide culinary water. Operation of the system has been de In addition, there are many irrigation sc ribed as fo llows: companies and other entities in Morgan and Summit Counties which obtain their Waters of the Weber River water supply from these two rivers. and tributaries are dis tributed in accordance with Federal reclamation projects, water rights defined in the inc 1 ud ing the Weber River proj ect, Ogden River Decree dated April the Ogden River project, and the Weber 1, 1948, the Weber River Basin project, were built since the Decree dated June 2, 1937, late 1920s to impound and distribute appropriate contracts and surplus water. As a result several agreements which al ter these large storage reservoirs and distribu decrees and other subsequent tion systems were constructed and the rights which have been recog Weber River Water Users Association, the nized. Storage rights for Ogden River Water Users Association, and Weber Basin Project were filed the Weber Basin Water Conservancy primarily in October 1955 anQ District were formed to sponsor, oper are junior to the early direct ate, and maintain these facilities. flow rights and thus take effect only after such prior Water Rights rights are satisfied. The majority of water stored under The waters of the Weber River and project water rights is stored its tributaries are considered to be during the snowmelt months. fully appropriated, and water rights Water is withdrawn from are administered according to various storage throughout the year Court decrees and contrac ts. The Weber for irrigation, municipal, River Decree of June 2, 1937, covers industrial and fish and rights of the main stem and all major wildlife purposes depending tributaries except the Ogden River, upon demands. Munic ipal and which is covered by a separate decree. indust rial water 1S reI eased Several contracts which have been made t h r 0 ugh 0 u t the yea r from between various right holders, such Pineview Reservoir and also as the water user associations, Utah from the Weber River Reser Power and Light Company, and the federal V01rs except during high 91 runoff periods when local months during most years, to obtain a sources below the reserV01rs year around cont inuous fl ow 0 f 5 to 10 are sufficient to apply cfs (142 to 284 £/sec) for recharge requirements. Water is would probably require the purchase of released for stream fishery existing direct flow or storage rights. purposes when other reI eases These and other costs outlined above are inadequate to maintain the should be passed on to the beneficiaries stream fi she ry. Irrigat io n of the recharge operation. The model of water is required starting in the system developed in this study May and c ont inu ing through provides information on the areal extent October. Irrigation reI eases and magnitude of pumping level improve vary widely depending on ment resul t ing from recharge and g1ves runoff patterns during the the b as i s for all 0 cat i ng t he cos t s year and in the case of equitably. abnormal and subnormal years. The operation of the reser A special improvement district voirs for conservation pur appears to be the most suitable form poses greatly reduces the of institution to finance and manage uncontrolled runoff during the recharge system. This is a govern high flow periods and 1S mental subdivision with powers to compatible with flood control 1 ev y t ax e son all t ax a b 1 e pro per t y regulations. Evacuation of within the district, to issue bonds, conservation storage capacity and collect charges or fees for ser based on runoff forecasts and vices rendered.' Its powers and author the flood control diagrams ity are limited to the purposes speci will have only a minor effect fied 1n the resolution creating the on the conservation storage in district. It is created by the board of that the reserV01rs are County Commissioners who can also serve essentially assured of filling as its board of trustees or they can in, controlling the potential appoint or arrange for election of other of high flows. (Stevens et trustees. It could act as the sole al. 1974, p. VI-30.) manager and operator of the recharge system or it could make arrangements Institutional Arrangements for with other organizations such as the Groundwater Recharge System Weber Basin Water Conservancy District to supply the water and operate the To establish a long-term ground system . water recharge system on the Weber River at the location indicated in this The details of the method of study will require some form of organi financing could be patterned after zational arrangement for financing and the groundwater replenishment system management. Water rights must be established and successfully operated purchased, the abandoned gravel pits to for several years in Orange County, be used for ponding must be acquired, California (Crooke 1958). A replenish diversion and conveyance facilities must ment assessment for each acre foot of be constructed, the system must be water extracted from the groundwater maintained and operated when in place, bas i n p r ov ide s the m a j 0 r sou r ceo f and the costs of all of these must be revenue. In the case of the Weber properly allocated to and collected from River recharge system being investi the beneficiaries. gated here, it woul d be appropriate to determine the boundaries of the district Although large surplus flows in the to encompass only that part of the order of 2000 cfs (56,630 9v/sec) pass groundwater basin benefitted by the the r e c h a r g e sit e for t wo tot h r e e recharge operat ion. Th is could be done 92 easily from information supplied by the construction. The cost estimate 1S model developed by this project. found in Table 15. Prompt Action to Obtain Land The actual .cost depends on con struction conditions and could be The principal recharge area 1n decreased below the estimate given if the mouth of Weber Canyon is ideal for excavation costs could be cut by utiliz recharge purposes. The land surface ing more existing basins. The costs of consists of coarse sand and gravel with purchase, trade, condemnation, lease, little vegetation. Active gravel pits and any other option for obtaining the take up part of the area. Most of the land required are not included. The center of the valley is still open, but repayment 0 f suc h a proj ec tis al s 0 along the sides SOme sc attered houses highly variable and dependent upon the and subdivisions are being built. In kind of financing. The cost benefit only a few years the opportunity to ratio would vary greatly depending on easily acquire land for a recharge whether a simple interest loan was project will be gone. Prompt action obtained, whether a low interest loan by the appropriate public agencies, was obtained from a state agency or either local or state, is imperative to other kinds of innovative financing retain this recharge resource for public could be found. The actual economics of use in the future. In the meantime, as pit preparation should be studied suggested earlier, the land could be further to obtain a better feeling for ut il ized for a park, pl ayground, golf initial costs a?d available financing. course and wetlands habitat. But now is the time for action to set thearea Recharge Operation aside for its ultimate use as an arti ficial recharge area. Each 0 f the three simul at ion runs based upon utilization of water at Recharge pit Construction Gateway in excess of the used water and Operation right appears to be unfavorable 1n terms of a cost benefit analysis based Costs associated with the construc on pump1ng 1 ift. Even when the total tion of a recharge facility are highly quantity of available water at Gate variable and dependent upon the recharge way is used the maximum cost savings method employed and the recharge loca from reduced pumping lifts total only t ion. The only rech arge method di s $13,380. This value barely meets the cussed herein is recharge by basins or yearly estimated operating costs shown pits. The best recharge location in Table 15 and does nothing to recover is the area next to the mouth of the initial construction costs. Weber Canyon. The recharge area chosen appears to be ideal because the soil is If all the available water which highly transmissive and numerous active passes Plain City and is wasted into the and abandoned gravel pits exist which Great Salt Lake were utilized, the are ideally suited as recharge basins. average cost savings due to decreased pumping lifts would be approximately The presence of gravel pits im $51,000 per year. When operation and proves the econom1CS of artificial maintenance costs are subtracted and the recharge because fewer initial costs remainder is applied on a $500,000 no would be incurred for pit excavation interest loan the sum would be cleared and preparation. Rough estimates of within 14 years. In comparison, a 10 costs for a recharge fac il ity have been percent loan for 30 years would require made with the basic assumptions that a yearly payment equal to approximately a recharge basin already exists and $53,000 which 1S again greater than the that a settling basin would require total yearly savings generated from 93 Table 15. Cost estimate of recharge system. Capital Costs 1. 13 acres @ $8,000/acre $104,000 2. Excavation 168,862 yd3 @ $3.00/yd3 507,000 3. Security Fence 3,140' @ $3.25/ft 10,000 4. Diversion Works 10,000 5. Contingencies (25%) 158,000 $789,000 Annual Operating and Maintenance Costs 1. Basin Maintenance $ 5,000 2. Weed & Algae Control 1,000 3. Misc. Office, Engineering and Legal Expense 2,000 4. Operating Personnel Salary 5,000 $ 13,000 recharge under the best assumptions. the viability of such a project. Direct state support of the recharge For example if pumping lifts were to project would also greatly affect the continue to increase in the future, econom1CS. the savings for a given quantity of recharge would be higher. Alternate In order to provide a cost benefit financing or changing interest rates ratio of between 1.5 and 2.0 the gener could greatly affect the ability to ated savings should be in the range from repay an initial loan. Rising energy $79,500 to $106,000. The only recharge costs would also change the economic simulation (under the limited assumed worth of recharge. conditions de:;cribed above) which falls within the above range 1S the one A complete economic analysis utilizing the hypothetical recharge of such a recharge project should quantities and distribution shown in include other benefits such as reduced Table 14. Weber River flooding, delay of flood waters into the Great Salt Lake, protec Other Economic Benefits tion of groundwater from contamination, reduction of water treatment costs for When economics is based solely water used for cul inary purposes, and upon the savings realized by a reduction benefit of increased pumping during in pumping 1 ifts and fixed construc tion drought. By including these types of costs, the value of artificial recharge benefits along with others mentioned as calculated herein appears to be above, the economic viability of artifi marginal. It must be remembered that cial recharge can be changed dramatical slight changes in the economic analyses ly thus opening the door to a successful could make a marked difference 1n artificial groundwater recharge project. 94 SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS Summary The economic benefit of an artifi cial recharge project when based solely The piezometric surface of the deep upon reduced pumping lifts and fixed confined aquifer which underlies much of construction costs appears to be small the Weber Delta area has declined from for all simulations but one. The simula 40 to 50 feet ·around Hill Air Force Base tion which had reasonable benefits was a over the last 30 years. The reason for .. result of utilizing the water currently this decline is twofold: first, there being wasted into the Great Salt Lake. appears to have been a decl ine in the The calculated benefit was found to be quantity of subsurface recharge from the approximately $51,000 per year. The mountain front from the mid 1960s to economic analyses performed herein do 1 9 81 . Sec 0 nd, the r e has bee nan in not include other benefits such as those crease in pumping demands for municipal derived from use of the recharge facili and indust rial uses which ut il ize the ties as a flood control device, reduced deeper higher quality water of the Delta water treatment· costs of water used for Aquifer system. The results from such a culinary purposes, and savings realized combination are that the storage poten by increasing energy costs. Each of tial of the aquifer has been reduced and these and other similar questions should that pumping Ii ft s have been inc reased . be answered by a detailed analysis before a complete economic evaluation The groundwater computer model can be made. presented herein has resulted in a reasonable simulation of yearly histori Conclusions cal trends of the piezometric water surface of the Delta Aquifer. A yearly The results obtained from the stochastic generation model and a computer model indicate that the monthly disaggregation model then size of the recharge basin ut il ized by produced Weber River streamflows to be the Bureau of Reclamation during used as stochast ic river recharge into the 1950s recharge tests is inadequate the groundwater model. These same to capture the maximum economic bene streamflows were also used in conjunc fits. To be economically feasible in tion with an estimate of the active terms of pumping lift the infiltration water rights on the Weber River to capacity would have to be increased indicate a quantity and distribution of either by increasing the driving head or unused available water at the Gateway by inc reasing the recharge basin size. station. Water was also found to be wasted into the Great Salt Lake based on Total available water at Gateway is values of streamflow at the Weber River highly irregular and unpredictable. The gaging station near Plain City. Subject quantity of water is completely depen to the limitations imposed by the water dent upon the management pract ic es of rights, various quantities and dis both the upstream and downstream water tribut ions of artific ial recharge were users. Each user varies his water usage then input into the groundwater model according to past and present climato and the results were compared with logical conditions. These conditions simulations without artificial recharge. also affect the quantity of water 95 diverted to, stored in, or released recharge, considering the savings from anyone of the instream storage real i zed from red uc ed pump ing lift s , reservoirs. Because water use practices and the fixed construction costs, is are so highly varied and difficult to that only with ideal management and predict, it is concluded that water financing will such a project be eco usage for recharge purposes based on nomically viable. Changes in the computations from water rights ~s not assumptions made or inclusion of other the best alternative. economic benefit s could greatly add to the desirability and practicality of The best and most reliable esti recharge. mates of the available recharge water would be to monitor and then use the Recommendations available quantity of wasted water which otherwise would enter the Great Further studies should be made of Salt Lake from the Weber River. There water right patterns for the Weber is a substantial amount of wasted River. These studies should include the water each year which enters the lake management practices of the various which thus could be put to beneficial reservoir operators as well as other use for artificial recharge. water users. It is recommended that the studies be done with the overall Two basic timing options were objective of utilizing any wasted water presented for management of a recharge which presently enters the Great Salt system. The first was to apply a con Lake. A study of this nature would stant and continuous supply of water for result in both ~he assurance that artificial recharge, and the second was sufficient water would be available and to apply a timing technique which that the instream users would not be applies recharge on an scheduled inter adversely affected by such a recharge mittent basis. Since continuous mun~c~ project. Such a study should also pal and indust rial use account for the determine if the economic benefit to any greatest proportion of total use, a one water user is sufficiently high to continuous supply would give maximum warrant voluntary partial allocation of year round pumping cost savings. A his water right for recharge purposes. continuous supply herein means that the recharge operation would be continued Land acquisition potential should whenever water is available. be studied further. Public agencies s h 0 u I d act prom p t I y tor eta i nth i s The marked decrease in piezometric recharge resource for future public use. well head which occurred near the canyon The economics of an art ific ial recharge mouth in the mid 1960s might be a good project are greatly improved when the indication of mountain front recharge initial excavation and construction quantity. Due to the few observation costs can be lowered. Although the wells in the area, the details of the potential for recharge into anyone of changes in both water we 11 levels near the many present gravel pits is high, the canyon mouth and mountain front re the ac t ua I s ~ze sand I ocat ions might charge are uncertain. The fact that the indicate an optimum recharge operation historical piezometric surface declined at a minimum initial investment. An with the same general pattern as the added benefit of land acquisition in the calibrated mountain front recharge recharge area of the Weber Basin would indicates that if natural recharge were be the future protection of this sensi to increase once again the piezometric tive area from contamination from urban surface would likewise increase. and industrial sources. The overall conclusion reached Well B-5-1-36bbb should be found regarding artificial groundwater and if possible prepared for further use 96 as an observation well. The quantity of greatly affects the response of the mountain front recharge entering the Delta Aquifer and that some of the Delta Aquifer system is important to the effects measured by the Bureau of maintenance of a proper water balance. Reclamation might have been due to Further declines of natural recharge natural causes. It is therefore recom will obviously increase pumping lifts mended that additional recharge tests be and improve the economics of artificial made with careful attention given to recharge. On the other hand if mountain avoid some of the same problems pre front recharge were to start a recovery viously encountered. It is believed trend the importance of artificial that this could be done with a minimal recharge would be diminished. For this expense utilizing existing basins and reason it 1S recommended that well that it should be done before a full B-S-I-36bbb either be reopened, another scale project is begun. adequate well located, or a new well drilled to provide a guide as to the A more detailed economic analysis nature of the local subsurface recharge. should be performed to include other benefits to the recharge project and During the recharge tests performed possible cost trends. Such a study could by the Bureau of Reclamation several show the various economic opt ions and problems such as freezing and basin possibilities available in terms of both clogging were encountered which affected the initial investments and long term the results of the recharge tests. It operation to better quantify the viabil has also been found that river recharge ity of artificial groundwater recharge. 97 SELECTED »IBLIOGRAPHY BoIke, E. L., and K.M. Waddell. 1972. surplus stream flow as a source for Groundwater conditions in the East artificial recharge to the ground Shore area, Box Elder, Davis, and water aquifer in Salt Lake Valley. Weber Counties, Utah, 1960-69. Report to the Utah State Division Technical Pub lication No. 35. S of Water Rights, Salt Lake City, State of Utah, Department of Utah. Natural Resources, Salt Lake City, Utah. Haws, Frank W. 1973. A study of water institutions in Utah and their Canfield, Ronald V. 1982. Hydrologic influence on the planning, develop series generation from the spectral ing and managing of water re density function. Utah Water sources. Utah Water Research Research Laboratory, Utah St ate Laboratory Report PRWG 79-1. University, Logan, Utah. Logan, Utah. Canfield, Ronald V. 1983. Personal Herbert, 1., M. Smith, and C. Bird. communication. Professor, Applied 1982. Personal communication Statistics Department, Utah State with regard to water level records University, Logan, Utah. February. availa~le through the USGS. United States Geological Survey, Carpenter, Carl H. 1978. Potential for Salt Lake City, Utah. recharge of aquifers 1n Utah Valley by artificial means. Nielsen, James, L. Douglas, David S. Bowles, W. Maxwell and Wangsgard Consulting Robert James, and Ronald V. Engineers, Salt Lake· City, Utah. Canfield. 1979. Estimation of water surface elevation probabili Crook, Howard W. 1958. A method of fi ties and associated damages for the nancing groundwater replenishments. Great Salt Lake. Utah Water ASCE, Journal of Irrigation and Research Laboratory, Utah State Drainage Division Vol 84, No. IR4. University, Logan, Utah. Fenneman, N. M. 1931. Physiography of Jenkins, Gwil im, M., and D. G. Watt s. we s t ern Un i ted S tat e s . Mc G r a w 1968. Spectral analysis and its Hill Book Co., New York, New York. appl ications. Holden-Day, Inc. , 534 p. San Francisco, CA. 825 p. Feth, J. H., D. A. Barker, L. G. Moore, Lazenby, A. J. 1938. Experimental R. J. Brown, and C. E. Viers. water-spreading for groundwater 1966. Lake Bonneville: Geology storage in the Salt Lake Valley, and hyd rology 0 f the Weber Del ta Utah, 1936. Transactions, American District, inc! ud ing Ogden, Utah. Geophysical Union, 19th Annual USGS Professional Paper 518, Meeting, 27-30 April 1938. National Washington, D.C. Research Council. Hansen, Keith L. 1978. A feasibility McGuinness, C. L. 1963. The role of study for using storm water and groundwater 1n the national 99 water situation. U.S. Geological Geological Survey, Sal t Lake Ci ty, Survey Water Supply Paper 1800, Utah. Washington D.C. 1121 p. Townley, Lloyd R., and John L. Wilson. Smith, Ralph E. 1961. Basic-data 1981. Desc ript ion of and users report no. 1: Records and wa ter- manual for a finite element aquifer level measurements bf selected flow model, AQUIFEM-l. Ralph we 11 s and chemic al ana lyses 0 f M. Parsons Laboratory for Water groundwater, East Shore area, Re sou rc e sand Hyd rodynam i c s . Davis, Weber, and Box Elder Coun Report No. 252. Massachusetts ties, Utah. United States Geo Institute of Technology, Cambridge, logical Survey and Utah State Massachusetts. Engineer's Office, Salt Lake Ci ty, Utah. United States Bureau of Reclamation. 1982. Notes and unpublished Stephens, J. C. et al. 1974. Ground- data wi th regards to USGS Profes water conditions in Utah, spring of sional Paper 518. Salt Lake City, 1974. Cooperative Investigation Utah. Report No. 13. Utah Department of Natural Resources, Division of Utah Department of Natural Resources, Water Resources, Salt Lake City, Division of Water Resources. UT. 1964-1981. Groundwater conditions in Utah, Spring 1963-1981, Salt Thomas, H. E. 1949. Artificial re- Lake City, Utah. Cooperative charge of ground water by the Investigations Reports Numbers City of Bountiful, Utah. Trans 2-10, 12-20. act ion s, Am e ric a n G eo ph Y sic a 1 Union. Vol. 30, Number 4. August. Valley Engineering. 1978. Water spreading feasibility study. Thomas, H. E. 1952. Groundwater Davis - Weber - Box Elder Counties, regions of the United States Utah. Report to the Utah State their storage facilities. U.S. Division of Water Rights, Salt Lake 83rd Congress, House Interior City, Utah. and Insular Affairs Comm., The Physical and Economic Founda Walton, William C. 1970. Groundwater tion of Natural Resources Vol. 3, resource evaluation. McGraw 78 p. Hill Book Co., New York, New York. Thomas, H. E., and W. B. Nelson. 1948. Wantland, D. 1956. Geophysical in- Groundwater in the East Shore vestigations in connection with area, Utah, Part I, Bountiful groundwater studies in the East District, Davis County, Utah. Shore area, Weber Basin Project, Utah State Engineer 26th Bienn. Utah. Unpublished Geology Report Rept. p. 53-206. No G-130. U.S. Bureau of Reclama tion, Denver, CO. Th om as, H . E., W. B . Ne 1 son, B . E . Lofgren, and R. G. Butler. 1952. Weber River 208 Areawide Wa ter Qual ity Status of development of selected Management PI an for Davis, Morgan, ground-water basins in Utah. and Weber Counties, Utah. 1977. Technical Publication No.7. Weber River Water Quality Planning State of Utah and United States Council. Volume 1, Ogden, Utah. 100 APPENDICES Copies of the Appendices are available on request from the Utah Water Research Laboratory, UMC 82, Utah State University, Logan, Utah 84322. 101