Analysis of basic data concerning ground water in the Yuma area, Arizona
No abstract available.
Arizona↗
Geology topics
H. E. Thomas
Publications and source records attributed to H. E. Thomas.
Lake Bonneville: Geology of northern Utah Valley, Utah
Lake Bonneville was a vast Pleistocene lake that covered 20,000 square miles in northwestern Utah and had a maximum depth of about 1,000 feet. It was a body of water comparable in size to modern Lake Michigan. Surveys of the unconsolidated deposits in the Lake Bonneville basin utilize the same methods used in studies of hard rocks, namely: separation of the deposits into mappable units and contacts between formations; observations of lateral and vertical changes in lithology; and plotting of these data on the map.
Utah↗
Hydrologic reconnaissance of the Green River in Utah and Colorado
The Green River, rising in Wyoming and draining high mountains in that state, northeast Utah and northwest Colorado, is a major tributary of the Colorado River. In the late summer, after the snow has melted from these mountains, the flow in the Green River reaches its minimum for the year. At that time a large proportion of the water in the river is returned to the atmosphere by evaporation and transpiration. During a 21-day period in September 1948, when the flow was least for the year, the average flow of the river as it entered Utah from Wyoming was 515 cfs. In the 437 miles of its course through Utah and Colorado evapotranspiration losses averaged 430 cfs. The average discharge of the Green River into the Colorado was about 975 cfs. Contributions to the river in Utah and Colorado totalled 890 cfsi including 560 from tributaries. The calculated ground-water inflow was about 330 cfs, of which about 75 percent was contributed within the Uinta Basin. Verv little ground water was contributed to the river in the lower 180 miles of its course, where the river flows through canyon lands of the Colorado Plateaus. These estimates are based upon information collected during a boat reconnaissance in September 1948, and upon data available from stream-gaging stations along the Green River and many of its tributaries. From these data an accounting was made of the water--as to both quantity and quality--in several segments of the river. For each segment determinations were made of the surface outflow, loss by evapotranspiration, and surface- and ground-water inflow. During the reconnaissance information was also obtained as to the relation of stream flow to regional geology and ground-water hydrology. No detailed hydrologic studies have yet been made within the drainage basin of the Green River. On the basis of this recomiaissance, detailed studies in the Uinta Basin, Browns Park, and Echo Park areas are recommended as highly desirable, because of the possible relations of ground-water hydrology to river-basin development projects. Similar reconnaissance can be of value in delineating the areas where detailed hydrologic studies would be most fruitful throughout the upper Colorado River basin.
Colorado, Utah↗
A hydrogeologic problem in the proposed Echo Park Reservoir, Colorado
Explore the source record for details and available documents.
Open-File Report↗
Status of development of selected ground-water basins in Utah
This technical publication consists essentially of abstracts of more detailed reports which have been published. Reference to existing reports are given in the text and in the bibliography, page 114.
Utah↗
Hydrologic reconnaissance of the Green River in Utah and Colorado
Explore the source record for details and available documents.
Open-File Report↗
Ground water in the East Shore area, Utah. Part I. Bountiful District, Davis County
The Bountiful district in Davis County, Utah, less than 10 miles from the heart of Salt Lake City, is rapidly becoming an integral part of the metropolitan area of Salt Lake City. It cannot achieve the development that its location merits unless the present water supplies are increased. The district is a fertile agricultural area favorably situated between the largest cities in the intermountain area and athwart the major routes of transportation and communication, but development of its residential, industrial, and agricultural potentialities will be restricted until existing water resources are supplemented by importation from other drainage basins that now have surplus water supplies. This conclusion is reached in the accompanying report by the Geological Survey, prepared in cooperation with the Utah State Engineer and the Davis County Water Users Association, and based on a 2-year investigation of the existing water supplies
Utah↗
Geology and ground-water resources of Cedar City and Parowan Valleys, Iron County, Utah
Cedar City Valley and Parowan Valley are situated in the eastern part of Iron County, in southwestern Utah. Both valleys are traversed by United States Highway 91, which skirts the west base of the High Plateaus of Utah. The sparse population of the valleys is chiefly dependent upon agricultural products for its livelihood. The climate of the region ranges from arid to semiarid, and the agricultural products are dependent upon irrigation by surface streams and, to an increasing extent during recent years, by water pumped from wells.
Utah↗
Ground water in Pavant Valley
The users of wells for irrigation in Pavant Valley, particularly in the Flowell district, have long been cognizant of their utter dependency upon ground water for livelihood, and were among the first in the State to make an organized effort to conserve supplies by prevention of waste. Since passage of the State ground-water law in 1935, the State Engineer has not approved applications for new wells in the areas of most concentrated development, and has deferred adjudication of existing water rights until adequate data concerning the ground-water resources become available. The investigation of ground-water resources in Pavant Valley was suggested by the State Engineer and constitutes one of a series that are being made in the important groundwater basins of Utah by the Federal Geological Survey in cooperation with the State Engineer. The investigation was under the general supervision of Oscar E. Meinzer, geologist in charge of the ground-water division of the Federal Geological Survey. H. E. Thomas, in charge of groundwater investigations in Utah, returned from military service overseas in time to assist in the completion of the manuscript, and edited the report.
Utah↗
Ground water in Tooele Valley, Tooele County, Utah
Tooele Valley is a typical basin of the Basin and Range Province located about 30 miles southwest of Salt Lake City. It is roughly 15 miles long and 10 miles wide and has a population of about 7,000. Bordered on the west by the Stansbury Range, on the east by the Oquirrh Range, and on the south by South Mountain, it opens northward to Great Salt Lake. The bordering mountain ranges are formed by Paleozoic rocks ranging in age from Lower Cambrian to Pennsylvanian but with the Ordovician and Silurian periods unrepresented. There is no sedimentary record of the interval between Pennsylvanian and Tertiary times, and the Tertiary, Quaternary, and Recent sediments are of continental origin. These continental deposits play the dominant role in the ground-water hydrology of the basin, and were mapped and studied in detail. Pleistocene sediments are of major importance because they form the surface rock over most of the area, and give rise to conditions which yield water by artesian flow in the lower part of the valley. The development of the present land forms in this area began with the folding of Paleozoic and probably Mesozoic sediments during the Laramide revolution. The cycle of highland erosion and lowland deposition thus initiated has continued through recurrent uplift along Basin-Range faults to the present day. The principal physiographic subdivisions of the valley were developed as a result of the Basin-Range faulting, which began early in the Tertiary and has continued to Recent times. There are about 1,100 wells in Tooele Valley, about 90 per cent of which yield or have yielded water by artesian flow. Most of them are located in the lower part of the valley below an altitude of 4,400 feet. These wells and many of the springs derive their water from the unconsolidated Quaternary sediments, which include discontinuous, lenticular and commonly elongated bodies of sand, clay, gravel, and boulders of alluvial origin alternating and inter-fingered with lacustrine beds of the same materials which are more regularly stratified and better assorted. The larger springs are intimately related to the bedding planes and faults in the bedrock and alluvial formations. The well assorted sands and gravels deposited along the shore lines of Lake Bonneville are important as recharge areas for the artesian reservoir.
Utah↗
Ground-water level fluctuations in Utah, 1936-45
Ground-water investigations in Utah by the Geological Survey of the U.S. Department of the Interior have been in progress since 1935, in cooperation with the Utah State Engineer. This cooperative work includes (1) determination of the fluctuations of water level in most of the developed ground-water areas in the state, based upon measurements which are tabulated and published annually by the Geological Survey; and (2) detailed investigations of specific ground-water areas to determine source, movement, disposal, quantity and quality of the ground water, and to show the relation of present development to the maximum economic development of which those areas are capable. Such detailed investigations have been completed during the past decade for areas in Iron, Millard, Salt Lake, Tooele, and Weber Counties, and are referred to in discussion subsequently. Similar investigations are now in progress in other areas in Davis, Iron, and Weber Counties.
Utah↗
The Ogden Valley artesian reservoir
Ogden Valley, in Weber County, Utah, contains an artesian reservoir from which the city of Ogden obtains all except a small part of its municipal water supply. A detailed investigation of the ground-water resources of Ogden Valley, and particularly of this artesian reservoir, was made by the Geological Survey, United States Department of the Interior, in cooperation with the city of Ogden between 1932 and 1934, and the results of this investigation have been reported by Leggette and Taylor. 1 The present paper, which might be termed a sequel to that report, is based on data collected during those years, augmented by records that have been obtained (1935-1940) by the Geological Survey as part of a State-wide project in cooperation with the Utah State Engineer. The conclusions drawn from the study of these records and presented in detail in the following pages are as follows: (1) The artesian reservoir is filled to capacity nearly every year during the spring run-off from melting snow; (2) after the annual freshet, the recharge to the reservoir is insufficient to balance the discharge from artesian wells, which ordinarily is at a maximum during the summer; the reservoir is depleted and is not filled again until the following spring; (3) during the periods when the artesian reservoir is not full the rate of recharge is more or less proportional to the inflow to the valley by streams, except that rain on the recharge area may be of sufficient intensity to contribute some water by infiltration and deep penetration; and (4) the artesian reservoir thus serves to store water that would otherwise be lost to Great Salt Lake in the excess spring overflow, and available records indicate that water used by increased draft from wells would be replenished in normal years by increased recharge during the spring freshet.
Utah↗
Geology and ground-water hydrology of the Mokelumne area, California
The Mokelumne River basin of central California comprises portions of the California Trough and the Sierra Nevada section of the Pacific Mountain system. The California Trough is divisible into four subsections-the Delta tidal plain, the Victor alluvial plain, tlie river flood plains and channels, and the Arroyo Seco dissected pediment. These four subsections comprise the land forms produced by the Mokelumne River and other streams since the Sierra Nevada attained its present height in the Pleistocene epoch. The Victor alluvial plain rises eastward from the Delta plain and abuts on the dissected Arroyo Seco pediment; in the Mokelumne area it is 12 to 16 miles wide and slopes between 5 and 8 feet in a mile. It includes relatively extensive tracts that are intensively cultivated and irrigated with water pumped from wells. The Victor plain has been compounded of overlapping alluvial fans along the western base of the Sierra Nevada. It is prolonged eastward into the pediment by tongues of alluvium along several of the present streams; thus it seems likely that the present stream pattern in the eastern part of the area has been fixed since dissection of the pediment began. Three of the four major streams-the Mokelumne and Cosumnes Rivers and Dry Creek-traverse the Victor plain in trenches which are 15 to 40 feet deep at the heads of their respective alluvial fans but which die out toward the west. The floors of these trenches, the historic flood plains, are from 100 yards to a mile wide. The exceptional major stream, which has not entrenched itself, is the Calaveras River. The Arroyo Seco pediment, which lies east of the Victor plain, was initially at least 8 to 15 miles wide and lay along the western foot of the Sierra Nevada entirely .across the Mokelumne area. Its numerous remnants decline 15 to 35 feet in a mile toward the west. The Sierra Nevada section adjoins and lies east of the California Trough. Its major ridge crests define a volcanic plain whose westward slope is' inferred to have been initially about 90 feet in a mile but is now about 180 feet in a mile, owing to tilting of the Sierra Nevada block in Pleistocene time. In and near the Mokelumne area the Sierra Nevada and California Trough together are roughly coextensive with a single structural unit. The Sierra Nevada constitutes a block that has risen with respect to adjoini;ng valley areas 'by simple rotation or tilting toward the west; it has not been warped or faulted -extensively. It is inferred that this block extends westward beneath the thick alluvial deposits of the trough without material warping or faulting. The oldest rocks of the Mokelumne region are the Carboniferous and Jurassic -rocks that compose the crystalline core of the Sierra Nevada. These are overlain unconformably by sediments of Tertiary age--in upward succession the lone, Valley Springs, Mehrten, and J.Jaguna formations. Of these formations all except the lone are newly discriminated, and type sections are described in the full text. These Tertiary sediments form a great wedge, thinnest along the mountain front to the east, where they have been truncated by erosion. They dip about 2° W. The lone formation (Eocene) consists chiefly of sandstone, clay, and shale; its maximum thickness is 450 feet. The Valley Springs formation (middle? Miocene) overlies the lone formation unconformably. It is composed largely of greenish-gray clay, shale, and sandstone derived from rhyolitic ejectamenta. These rhyolitic deposits are confined to narrow channels in the higher part of the Sierra Nevada, but they spread fanlike over the lower western edge of the mountain block, where they attain a maximum thickness of 525 feet. The Mehrten formation (upper? Miocene and lower Pliocene?) comprises the andesitic rocks that constructed the Sierran volcanic plain. In the Mokelumne area it consists chiefly of sandstone and siltstone but includes, as a minor though conspicuous part of the formation, layers and tongues of resistant breccia or agglomerate, which are presumed to have originated as mud flows. Nonfragmental andesite is not known to occur in the Mokelumne area, although several possible vents occur farther east. In the eastern part of the area the Mehrten formation truncates in turn the Valley Springs and lone formations and the pre-Cretaceous rocks; in the western part the Mehrten formation (andesitic) interfingers with the underlying Valley Springs formation (rhyolitic). Its maximum measured thickness is 400 feet. Few of the irrigation wells are so deep that they can be said with assurance to reach the Mehrten formation. The Laguna formation (Pliocene? and possibly lower Pleistocene) comprises poorly sorted, nonandesitic fluviatile sedimentary that overlie the Mehrten formation. It is inferred to be essentially parallel to and tilted equally with the Mehrten formation and to be about 400 feet thick. The Arroyo Seco gravel (presumably middle Pleistocene) veneers the Arroyo Seco pediment. At its easternmost outcrops the formation is composed of pebbles, cobbles, and boulders in a matrix of brick-red sand and silt; farther west, down the slope of the pediment, it becomes pr9gressively finer. It is inferred that the Arroyo Seco gravel is a coarse fraction of the rock waste that was transported from the Sierra Nevada after the Sierran.block was tilted in Pleistocene time. It is inferred further that the correlative of the Arroyo Seco gravel in the California Trough is a wedge-shaped mass of sediments whose base is the tilted Laguna formation and whose top can be interpolated by projecting a hypothetical surface through the remnants of the pediment. The Victor formation comprises the fluviatile sand, silt, and gravel that built the Victor alluvial plain over the hypothetical equivalent of the Arroyo' Seco gravel along the axis of the California Trough and against the western front of the dissected pediment to the east. The formation is thought to be about 100 feet thick along the western margin of the Mokelumne area, according to an estimate based upon projecting the slope of the Arroyo Seco pediment westward beneath the Victor plain. The Mokelumne area lies on the fertile central plain along the Mokelumne River about the city of Lodi, in northern San Joaquin County, and has been intensively developed for the cultivation of grapes, deciduous fruits, and other crops. Of necessity its great productiveness is maintained by irrigation. Extensive irrigation from wells began about 1907 and has increased steadily until in 1932 about 50,000 acres (80 percent of the area) was watered in that manner. The specific question at issue is the extent to which the supply of ground water and hence the productiveness of the area are dependent upon the water flowing in the Mokelumne River and the extent to which that productiveness may be influenced by regulation of the stream--:in particular, by the substantial regulation of the river that is accomplished by the Pardee Dam of the East Bay Municipal Utility District, which began to function in March 1929. The depth of 1,447 irrigation wells in five townships in the central part of the area (T. 3 N., Rs. 6 and 7 E., and T. 4 N., Rs. 6 to 8 E.) ranges from 20 to 910 feet. About half the wells bottom within a 100-foot zone whose base is 75 feet below the projected Arroyo Seco pediment; essentially that zone constitutes the Victor formation. Only 6 percent of the wells bottom within the next lower 25- foot zone, but the percentage increases sharply for depths still greater; it is inferred that impervious strata are relatively persistent between 75 and 100 feet below the projected pediment and that these are the uppermost part of the Arroyo Seco gravel. Of 580 observation wells known to bottom in the Victor formation, essentially all appear to indicate a regional water-table stage; thus the water is essentially unconfined. On the other hand, nearly all wells so deep that they reach the Arroyo Seco gravel or some underlying formation tap confined water. Near the Mokelumne River the water levels in these deep wells stand below the water table, which is semiperched. In most deep wells remote from the river the water level stands above the water table except during the pumping season. Fluctuations of ground-water levels are ascribed to moving or changing load on the land surface, earthquakes, variation of barometic pressure, ground-water draft by vegetation, infiltration of rain and certain indirect effects of rainfall, infiltration of water applied to the land for irrigation, variation in the discharge of streams, and pumping from wells. In the eastern part of the central district, between Clements and the vicinity of Lockeford, it is inferred that (1) the river and the water in the alluvium of the flood plain are not insulated from the water in the sediments that form the adjacent Victor plain; (2) locally if not generally, however, there are discontinuities in pervious strata along the outer margin of the flood plain, where the water table passes from the alluvium into the enclosing sediments, so that percolation of ground water is impeded materially at that margin; (3) rising river stages set up ground-water waves that store relatively large volumes of water in the alluvium close to the river, whereas falling stages cause much of that stored water to percolate back into the river, weeks and even months lapsing before the ground-water stage becomes steady within the flood plain; and (4) seepage loss from the river into the alluvium tends to be intermittent and to alternate with seepage gain, the rate of loss or gain lagging weeks or months behind the fluctuations of river stage and lagging more for moderate changes at low stage. However, in the succeeding reach downstream as far as Woodbridge, it is inferred that percolation of ground water is not impeded generally along the outer margin of the flood plain and that the river tends to lose almost continuously by seepage rather than intermittently, although the rate of loss fluctuates somewhat in response to changing river stage. The yearly pumpage for irrigation has been as much as 114,600 acre-feet (1928- 29), and there have been as many as 2,500 wells equipped with irrigation pumping plants (1931). Commonly the wells are pumped only in daylight and are idle over week-ends and holidays, also during and after protracted rainstorms in the early part of the season. In a small district near Victor pumping in recent years has begun in January or February, has reached its height in March, and largely has passed by April. In outlying districts general pumping has begun as late as May, reached its height in June or July, and waned by September. Since 1907 the water table appears to have declined steadily in most of the Mokelumne area except along the river. The decline was least in the Woodbridge Irrigation District, where in four typical wells. the average decline from 1907 to 1937 was 3 feet, or 0.15 foot a year. Among 18 shallow wells in the district of most intensive pumping the average recession of the water table from 1907 to 1927 was 11 feet, or 0.55 foot a year; the greatest measured recession was 15 feet, or 0.75 foot a year. From 1927 to 1933 the water table declined 5 feet or more over most of the central pumping district except within 2 miles of the Mokelumne River, and the greatest measured decline was 9 feet. The area of material recession ,extends 4 to 7 miles eastward beyond the central pumping district, whence it is inferred that pumping has drawn gradually on remote ground-water storage. It is inferred that the Mokelumne River ordinarily has been a losing stream between the Mehrten dam site, near Clements, and the Woodbridge Dam, the area that received the percolate having been triangular with its upstream and having included about 5,200 acres of the flood plain and 36,500 acres in outlying districts to the north and to the south. Mean fluctuations of the water table within the area receiving percolate from ihe river are believed to indicate that relatively little water is drawn from outside the area. Accordingly, simple storage methods are competent for a ground-water inventory. It is inferred that the rate of seepage loss from the river depends jointly upon river discharge, stage in the Woodbridge Reservoir, and groundwater pumpage. The foregoing inferences lead to the following conclusions with respect to ground-water replenishment by seepage loss from the river in the intensively cultivated district about Lodi: (1) The annual replenishment has tended to increase for at least two decades, owing to the gradual increase in head between surface water and ground water as ground-water levels have been lowered progressively by pumping; (2) annual replenishment has tended to increase, especially in recent years, owing to gradually prolonged use of the Woodbridge Reservoir, for thereby a relatively large wetted area and great differential head have been maintained for an increasing term; (3) the rate of replenishment tends to be greater under regulation than under the so-called natural regimen, to the extent that regulation has maintained a moderately large wetted area and stage in the river through the later part ·of each pumping season, whi1e the ground-water levels have been lowest. Moreover, for any particular yearly run-off below the Mehrten dam site, the replenishment by seepage would tend to be greater under the regulated regimen to the extent that fluctuations in discharge were suppressed, for the greatest yearly mean stage and mean wetted area would be afforded by constant discharge. -Thus, diverting water out of the Mokelumne River Basin at the Pardee Dam does not necessari1y-entail a diminution in ground-water replenishment by seepage loss along the lower reach of the stream, at least in the replenishment beneath the Victor plain above the gaging station at Woodbridge. Rather. the Pardee Dam affords a means for so regulating the discharge as to effect a maximum ground-water replenishment with-a given run-off in the natural channel. Bodies of ground water perched above the regional water table are common in the Laguna formation, especially in its lower part. Conspicuous bodies occur about 3 miles south of Clay, in a district between 1 mile and 5 miles south of Clements, and along Dry Creek in T. 5 N., Rs. 7 and 8 E. From the relation between the water table and the piezometric surface for water confined in deep aquifers, the area receiving percolate from the Mokelumne River may be divided roughly into (1) a central area, extending not :p1ore than half a mi1e beyond the flood plain, in which the piezometric surface is inferred to have stood below the water table throughout the term of the investigation and hence in which the difference in head has favored the percolation of water from shallow beds into deep beds in all seasons, and (2) an outlying area in which the difference in head likewise favors downward percolation into deep beds during the pumping season but favors upward percolation during the nonpumping season. This outlying area includes about 75 percent of the segment of the Victor plain that receives percolate from the river. From 1927 to 1933 the subartesian head that existed during the nonpumping season in the area remote from the river tended to increase; it is therefore inferred that the relative opportunity for seasonal recharge of the shallow water-bearing beds by underfeeding has likewise tended to increase. On the other hand, the negative differential head in wells near the river also has tended to increase; thus in this central area the opportunity for discharge of water from shallow beds by downward percolation has probably tended to increase. It is believed that ground-water storage within the area near the river is not decreased materially by" discharge westward through deep pervious beds, also that the yearly addition to ground-water storage in the outlying area by deep percolation from a remote easterly source is scant and for all practical purposes is offset by downward percolation along the river.
California↗
Artesian-water levels and interference between artesian wells in the vicinity of Lehi, Utah
In the vicinity of Lehi, Utah, about 25 miles south of Salt Lake City, supplies of artesian water are obtained at depths of 75 to 750 feet from beds of sand and gravel of Pleistocene age. Individual beds are probably lenticular and irregular in shape, as is characteristic of the stream and lake deposits in many parts of the Lake Bonneville Basin. The artesian supplies are obtained from aquifers or groups of aquifers that are more thoroughly separated by impermeable materials than the artesian aquifers of some other ground-water areas in Utah. Most of the wells are between 130 and 200 feet deep. The artesian area in the vicinity of Lehi is only a small part of a ground-water unit that probably includes most of Utah Lake Valley. The ground-water reservoir in Utah Lake Valley was seriously depleted after the years of subnormal precipitation that culminated in the drought of 1934. However, in the vicinity of Lehi the static levels in 1934 were about the same as during 1904, a year which marked the culmination of a previous drought period. The water levels in the summer of 1935 were about the same as in 1934, indicating that the recharge to the ground-water reservoir was again sufficient to balance the discharge; and during the following year there was a marked rise of the water level in all wells, commonly 5 to 10 feet in amount. The static levels in the vicinity of Lehi fluctuate each year through a range of as much as 15 feet and are ordinarily highest during March or April and lowest during August or September. This fluctuation is due in part to the closing of flowing irrigation wells during the winter. A series of tests was made to determine the extent of interference between artesian wells. Among the wells that are between 130 and 200 feet deep, the operation of certain wells was found to cause a change in the static level in wells as much as 1 1/5 miles distant. The operation of these shallower wells, however, had no apparent effect upon the static level in the wells more than about 200 feet deep nor did the operation of these deeper wells appear to affect the static level in the shallow wells. The deep and shallow aquifers thus appear to be separated by fairly continuous beds of impermeable material.
Utah↗
Investigations conducted by the U.S. Geological Survey: A part of Chapter 5 in Twenty-first biennial report of the State Engineer to the governor of Utah: 1936-1938
A summary of past investigations in Utah and a description of the work done during the 1934-36 biennium are included in the State Engineer’s Twentieth Biennial Report (pp. 91-106). Co-operative investigation with the State Engineer, begun on July 1, 1935, has been continued during the past biennium. To provide for this work, the 1935 Utah State Legislature appropriated \$10,000 to the State Engineer, this sum being matched by the U. S. Geological Survey during the biennium ending June 30, 1937. During its 1937 session the State Legislature appropriated \$5000 for continuation of co-operative work in underground waters. An equal sum was provided by the U. S. Geological Survey and investigations have continued during the fiscal year ending June 30, 1938.
Utah↗
Ground water investigations in Utah to June 30, 1936: A part of Chapter 8 in Twentieth biennial report of the State Engineer to the governor of Utah: 1935-1936
During the past few years of drouth the importance of ground-water supplies has become more fully appreciated. During this time, because of subnormal replenishment of the ground-water reservoirs and the increased withdrawals from wells, the ground-water levels have declined in most developed areas in the State, a condition which has made the well owners acutely aware that ground water is not inexhaustible. Numerous cases of contention between well owners resulted in increased demands for adequate regulation of the appropriation and use of ground water. Realizing that more information concerning the ground water of the State was imperative, not only to administer the ground-water regulations but to prepare for the conservation and replenishment of existing supplies and development of new supplies, the State Legislature enacted, during its 1935 session, Senate Bill 206, which authorized the State Engineer to make an investigation of the ground water of the State. To provide for the expenses of the investigation, the bill allotted /$10,000 to the State Engineer, this sum to be matched by a State or Federal organization, and the investigation to be carried out co-operatively during the biennium beginning July 1, 1935. A co-operative agreement between the State Engineer and the United States Geological Survey was made on July 1, 1935.
Utah↗