Utilization of WaterDuring the course of the investigation information was obtained on 543 wells and springs in Finney and Gray counties. All known irrigation, public supply, and industrial wells in the two counties were visited, and all available data concerning them were obtained. No attempt was made to obtain data on all the domestic and stock wells. Of the wells listed in the well tables (pp. 184-224), 129 are out of use, either temporarily or permanently. The water supplies of the others are as follows: entirely domestic, 59; entirely stock, 40; domestic and stock, 48; irrigation, 244; public supply, 9; and industrial, 13. One well (269) drilled by the Division of Water Resources of the Kansas State Board of Agriculture is being used exclusively as an observation well. The principal uses are described below.
Domestic and Stock SuppliesMost of the rural residents of Finney and Gray counties derive their domestic supplies from drilled wells of small diameter equipped with lift or force pumps operated by windmills or by hand. A few obtain domestic supplies from dug wells or from bored wells. In the valley areas where the water table is shallow, some domestic supplies are obtained from driven wells equipped with hand-operated pitcher pumps. Livestock supplies are generally derived from drilled wells equipped with windmills. In the northeastern part of Finney County, springs that yield sufficient water for livestock are found. On many of the upland farms, the same well commonly furnishes water for domestic use and for watering livestock. Most of the domestic and livestock wells yield only a few gallons of water a minute.
The ground waters in this area, although hard, generally are satisfactory in chemical character for most domestic uses (see Quality of water).
Industrial SuppliesThe industrial uses of ground water in this area include cooling, manufacture of ice, water for steam boilers, and use in the refining of sugar from sugar beets. The suitability of ground water for industrial use depends upon its chemical character and temperature. Water used in boilers should be relatively free from foaming and scale-forming constituents. The ground water in much of the area is not of suitable chemical character for boiler use and it is, therefore, necessary to treat the water to reduce the hardness. Some ground water is used for cooling in the area. The advantage of using ground water for this purpose is its relatively low uniform temperature throughout the year. The temperature of the water in 50 representative wells was found to range from 57 degrees to 62 degrees F. and averages about 59 degrees F. Some homes and business houses in Garden City are known to use water from small wells for air-conditioning, but no attempt was made to obtain records or pumpage estimates for these wells.
The largest single user of ground water for industrial use in the area is the Garden City Company at Garden City. The water is used chiefly for steam to generate electricity at the power plant and in the manufacture of beet sugar. The Garden City Company is situated in the Arkansas valley in the southwestern part of Garden City. The water supply is obtained from three deep wells (304-306), four batteries (307-310) of four shallow wells each, and one battery (311) of three shallow wells. Two of the deep wells (305 and 306) are gravel-walled wells 24 inches in diameter and 180 feet deep; the other (304) is 16 inches in diameter and 260 feet deep. All of the deep wells obtain water from sand and gravel in the Ogallala formation. Each well is equipped with a deep-well turbine pump powered by an electric motor. The reported yields of the wells are 300, 500, and 600 gallons a minute. Water from these wells is reported to be relatively soft.
The shallow wells are 21 inches in diameter, are gravel-walled, and are 48 feet in depth. Each battery of wells is equipped with a horizontal centrifugal pump operated by an electric motor. The water supplied by the shallow wells is derived from coarse alluvial gravels and has a high mineral content. The yields of the shallow well plants range from 900 to 1,500 gallons a minute.
In 1939, the Garden City Company pumped nearly 130,000,000 gallons of water from the three deep wells and about 1,700,000,000 gallons from the shallow wells. Most of this water was pumped during the fall when the sugar factory was in operation.
The Garden City Ice Company at Garden City utilizes water from two wells in the manufacture of ice. One well (220) is 125 feet deep and is equipped with a 1 1/2-inch centrifugal pump powered by an electric motor. This well derives water from Pleistocene deposits or the Ogallala formation and yields about 15 gallons a minute. Water from this well is used to make ice. Because of the hardness of the water lime treatment is used. About 4,500 gallons of water a day are pumped from this well during the summer months. The other well is 35 feet deep and obtains water from coarse gravel in the alluvium. It is equipped with a 3-inch centrifugal pump and an electric motor and is reported to yield 175 gallons a minute. Untreated water from this well is used in the cooling coils at the ice plant. About 252,000 gallons of water are pumped from this well each day during the summer.
The Atchison, Topeka and Santa Fe railway has wells at Garden City, Cimarron, and Montezuma that supply water for locomotive boilers. The railroad well (222) at Garden City is 202 feet deep and taps the Ogallala formation. The harder water in the alluvium has been cased off. The well is equipped with a 6-inch centrifugal pump powered by an electric motor and is reported to yield 250 gallons a minute. Because of the hardness of the water, it is necessary to add lime and phosphate to prevent the formation of scale in the boilers.
The railroad well (460) at Cimarron is 129 feet deep and also derives its water from the Ogallala formation, the water in the overlying alluvium having been cased off. The well is equipped with a centrifugal pump and electric motor and yields about 85 gallons a minute with a drawdown of about 22 feet. The water is treated in the same manner as that from the well at Garden City.
The Santa Fe well (510) at Montezuma, in southern Gray County, is 300 feet deep, is 10 inches in diameter, and is gravel packed. The water level in the well is reported to be 118 feet below land surface. The well is equipped with a deep-well turbine pump and electric motor and is reported to yield only 45 gallons a minute with a drawdown of 32 feet.
Based on reports and estimates, about 1,945,000,000 gallons of water was pumped from industrial wells in Finney and Gray counties in 1939. Of this amount, about 1,937,000,000 gallons was pumped from wells at Garden City, in Finney County, and 8,000,000 gallons from wells in Gray County.
Public SuppliesThe cities of Garden City, Cimarron, Montezuma, and Copeland have public-water systems supplied by ground water pumped from wells. The smaller communities in the area are supplied from private wells, each family having a well of its own. Descriptions of the public-water supplies follow.
Garden City--Garden City (population, 6,285) is supplied by seven deep wells (181, 208, 223), all of which are in the Arkansas Valley within the city limits and all of which derive water from the Ogallala formation, the water in the alluvium having been cased off. Well 181 is 258 feet deep, is gravel packed, is equipped with an electrically driven turbine pump, and has a reported yield of 650 gallons a minute. Well 208 is 299 feet deep, is gravel packed, is equipped with an electrically driven turbine pump, and is reported to yield 500 gallons a minute with a drawdown of about 17 feet. Well 223 consists of five gravel-packed wells, each 250 feet deep, connected by suction lines to four horizontal centrifugal pumps. Three of the pumps are driven by electric motors; the other pump is driven by a natural-gas engine and is used only in emergencies. Any number of the pumps can be operated at the same time and water can be withdrawn from one or all of the wells. The capacity of the pumps ranges from 500 to 600 gallons a minute.
Water is pumped from the wells directly into the mains, the excess going into a 215,000-gallon standpipe. The daily capacity of the system is about 4,500,000 gallons. The maximum daily consumption at Garden City is 1,500,000 gallons, and the average daily consumption is 600,000 gallons: An analysis (181) of a composite sample of water from the city wells is given in table 20. Although the water is hard, it is not treated.
Cimarron--Cimarron (population, 1,004) is supplied by two wells (459 and 461) that tap the Ogallala formation. The wells are 180 feet deep, the upper part of each well being cased off to prevent entrance of water from the alluvium. Each well is equipped with a turbine pump driven by an electric motor. Well 459 has a reported yield of 190 gallons a minute and is used most of the time. Well 461 is seldom used, for if it is pumped to capacity (175 gallons a minute) fine sand enters the well. When it becomes necessary to use this well, it is pumped at the rate of about 90 gallons a minute.
Water is pumped from the wells directly into the mains, the excess going into a 126,000-gallon standpipe situated on the river bluff north of town. The daily capacity of the system is about 288,000 gallons. No figures on consumption of water were obtainable. An analysis (459) of a sample of the water is given in table 21. The water is moderately hard and is not treated.
Montezuma--Montezuma (population, 340) is supplied by two wells (511 and 513) that tap sand and gravel in the Pleistocene deposits. The wells are 160 and 170 feet deep and are equipped with turbine pumps powered by electric motors. Well 511 has a reported capacity of 100 gallons a minute with a drawdown of about 18 feet. The water level at Montezuma is about 112 feet below the surface. The city engineer reports that the water level in well 513 drops below the bottom of the intake pipe when the pump is operated to its full capacity, which is about 50 gallons a minute. For this reason the well is used only in emergencies. Well 511 is capable of supplying the quantity of water needed by the city, but the water contains an objectionable amount of fine sand. The existing wells are not properly constructed so as to exclude the fine sand. The logs of three test holes indicate that a satisfactory well could be put down within the city limits (see logs 26a, 26b, and 26c). The city is contemplating drilling a new well at one of these test-hole locations.
Water is pumped from the wells directly into the mains, the excess going into a 50,000-gallon elevated steel storage tank. The average daily consumption at Montezuma is about 50,000 gallons. An analysis (511) of the water is given in table 21. The water is moderately hard, otherwise it is of good chemical quality and is not treated.
Copeland--The water supply of Copeland (population, 262) is obtained from one 16-inch well (538) 248 feet deep, and one 15-inch well (539) 252 feet deep. The water is derived from the Ogallala formation or the Pleistocene deposits, or from both. Both wells are equipped with turbine pumps, the one in well 538 being driven by an electric motor and the one in well 539 being driven by a natural-gas engine. The wells are each reported to yield 50 gallons a minute.
Water is pumped from the wells directly into the water mains, the excess water going to an elevated steel storage tank having a capacity of 50,000 gallons. The daily capacity of the system is about 140,000 gallons. Figures on the consumption of water at Copeland were not obtainable. The water is moderately hard, but otherwise is of good quality. (See analysis 538, table 21.)
Based upon reports and estimates, the amount of water pumped from public supply wells in Finney and Gray counties during 1939 was about 240,000,000 gallons.
Irrigation SuppliesAgriculture is the principal and most important industry of this area. One of the primary requisites of any agricultural area is an adequate supply of moisture to meet the growth requirements of the crops raised. For this reason it has been necessary to find means of supplementing the low precipitation in this area with irrigation. The first practice developed was gravity irrigation, or irrigation by direct diversion from the river through ditches (pl. 5B). This practice grew until it reached its present state of development about 1900 (Anon., 1939). In 1940, there were 11 ditches that diverted Water from Arkansas River and irrigated land in western Kansas. Water from 7 of these ditches is used to irrigate land in Finney and Gray counties. Table 9 gives the names of these ditches, the location of headgates, and the total number of acres irrigated by each ditch in 1939.
Table 9--Diversion ditches along Arkansas River in western Kansas showing location of headgates and total acreage irrigated by each in 1939.
1. Anon., 1939
The acreage listed in this table includes the total number of acres irrigated by each ditch and not just the acreage irrigated in Finney and Gray counties. Table 10 gives the annual diversions of each of the five major ditches since 1924.
Table 10--Annual diversion of the five major diversion ditches in western Kansas for the fifteen-year period from October 1, 1924 to September 30, 1939, in acre-feet (1).
1. From records of the Division of Water Resources, Kansas State Board of Agriculture
The use of surface water from Arkansas River for irrigation has not been too successful for several reasons. Arkansas River does not have a consistent flow but is characterized by flash floods of large volume followed by long periods of very low flow. The flash floods are useless for irrigation because the land can only take a certain amount of water at any one time and the water should be distributed according to crop requirements throughout the growing season (Anon., 1939). Much of each flood flow, therefore, passes downstream unused.
It has been pointed out by the Bureau of Agricultural Economics (Anon., 1939) that there has been overdevelopment in the use of surface water for irrigation in western Kansas. The development of the use of surface water continued until all available river flow had become so overappropriated that it was necessary to adjudicate the rights to the use of water. Overdevelopment reached the point where there was more land under the ditches than could be irrigated with the water available. As a result some ditches were abandoned and the available water had to be rationed to the others. At the present time the Division of Water Resources of the Kansas State Board of Agriculture performs the duties connected with allocating the water.
In 1905-1908 the Bureau of Reclamation constructed 13 irrigation-well plants in the Arkansas valley just west of the Kearny-Finney County line (McLaughlin, 1943, p. 88). Each plant comprises five wells ranging in depth from 30 to 60 feet. The water is pumped into a concrete ditch, is siphoned under Arkansas River, and is carried to a booster station about 1 mile east of Deerfield, where the water is pumped into the Great Eastern canal on the upland. According to McLaughlin (1943, p. 88), approximately 3,500 acre-feet of water was withdrawn from the ground-water reservoir by these wells in 1939. The Great Eastern canal carries the water into Finney County where it is used to irrigate land on the uplands in the western part of the county. In Finney County the development of ground water pumped from wells began about 1915, continued rather steadily from 1920 to 1930, and development increased rapidly from 1930 to the present time.
During the summer and fall of 1940, an inventory was made of the irrigation wells in Finney and Gray counties, and estimates were obtained of the total pumpage and number of acres irrigated. Detailed records of all irrigation wells are given in tables 22 and 23 and the locations of the wells are shown on plate 2. Records were obtained for 244 irrigation wells in this area. The total reported area irrigated from these wells in 1940 was 21,860 acres, an average of about 89 1/2 acres to the well. Of the 244 irrigation wells, 183 are in the Arkansas valley and 61 are on the uplands either north or south of the Arkansas valley. Table 11 shows the number of irrigation wells, irrigated acreage, and the average number of acres per well by counties and by topographic position.
Table 11--Number of irrigation wells recorded and acreage irrigated with water from wells in Finney and Gray counties in 1940
It will be noted in this table that the average number of acres irrigated by each well is greater for the upland wells than it is for the wells in the valley. This difference is not the result of greater yields from upland wells, but is due to the great number of small irrigation wells in the valley that decreases the average acreage per well. Another factor causing the difference in average acreage is the greater use of surface water from diversion ditches for irrigation on the uplands. Many of the small irrigation wells in the Arkansas valley in the vicinity of Garden City irrigate only 1 to 15 acres. Large wells in the valley, however, irrigate as much as 200 acres or more. In table 12 the number of irrigation wells in Finney and Gray counties are classified according to the irrigated acreage. There are more small irrigation wells in this area than are listed in table 12, but no attempt was made to obtain records for all of the very small irrigation wells concentrated in and near Garden City.
Table 12--Number of irrigation wells in Finney and Gray counties in 1940 classified according to acreage irrigated.
An attempt was made to determine the quantity of water pumped annually from irrigation wells in the Arkansas valley and on the uplands in Finney and Gray counties. Reported estimates were obtained from well owners. For wells that are pumped by electricity in Finney County pumpage estimates were computed from records supplied by the Garden City Company of the total number of kilowatt-hours of electricity consumed in 1939. Mr. Kenneth D. McCall, engineer for the Division of Water Resources of the Kansas State Board of Agriculture, assisted in obtaining these data. The estimated total quantity of water pumped for irrigation in Finney and Gray counties in 1939 was about 32,000 acre-feet. Of this amount, about 29,000 acre-feet was pumped from wells in the Arkansas valley and 3,000 acre-feet was pumped from upland wells. Annual pumpage for irrigation varies from year to year--the amount of pumpage varying indirectly with the amount of precipitation. Pumpage during 1939 was probably much more than the average annual pumpage in these counties, for the rainfall during 1939 was far below normal.
Yields of irrigation wells--The yields of irrigation wells in Finney and Gray counties range widely. Small wells used to irrigate trees or small gardens yield only a few gallons a minute, whereas larger wells yield from, 500 to as much as 3,750 gallons a minute. Most of the yields of irrigation wells given in the table of well records were reported by the owners or tenants of the wells, but the yields of many of the irrigation wells were measured by K.D. McCall and M.H. Davison, of the Division of Water Resources of the Kansas State Board of Agriculture, by P.H. Browne of the Johnston Pump Company, and by E.F. Stoeckly, engineer for the Garden City Company. In 1941 and 1942, Melvin Scanlan of the Division of Water Resources of the Kansas State Board of Agriculture, and Woodrow Wilson of the Federal Geological Survey made several pumping tests on irrigation wells in this area. The yields of wells determined by pumping tests are given in table 13 and table 14 and in the tables of well records (tables 22 and 23).
A Cipolletti weir or a Collins flow gage was used in making measurements of the discharge. Drawdowns in pumping wells were measured by an electrical contact device. When the pumps were not running, a steel tape was used for measuring the water levels. The yields of the single-well irrigation plants ranged from 348 to 1,770 gallons a minute and the specific capacities ranged from 10 to 141. The drawdown in most wells ranged from 6.2 feet to about 50 feet. Well 150, however, had a drawdown of 135 feet, which is uncommonly large.
All of the battery-well plants on which pumping tests were made are in the Arkansas valley. The plants consist of from 2 to 14 shallow wells connected to one horizontal centrifugal pump (pl. 6). Drawdowns were measured in only 9 of the 16 battery-well plants. The aggregate discharge of these wells ranged from 520 to 2,790 gallons a minute and the average drawdown ranged from 6.7 feet to 11.8 feet. The average specific capacity for each well in a battery ranged from 14.3 to 51.6. Table 15 gives the range in discharge of battery-well plants according to the number of wells composing the plants. The table includes discharges reported by owners and tenants and measured discharges, and indicates the wide range in discharge obtained from battery-well plants having the same number of wells.
Table 15--Range in discharge of battery-well plants according to number of wells in plant. (Includes both measured and reported discharges.)
There are many factors that determine the yield of wells. Probably the most important factors are the construction; the diameter of the well casing; the type of casing and perforations; the development and finishing of the well, whether gravel-packed or not; the age of the well; the character and thickness of the water-bearing material; and, for battery wells, the spacing of the wells. The quality of the water may also be an important factor, for water that readily forms incrustations may eventually fill the perforations in the well casing, thus causing a decrease in the yield of the well.
The yield from a battery of wells may be much greater than the yield from a single well, but the yield of each well is less than if the other wells were not being pumped. If the desired quantity of water is not obtained at first, more wells may be added to the battery.
The yield does not increase proportionately with the number of wells, however, because of mutual interference between wells. McCall and Davison (1939, p. 34) made a series of tests on a battery-well plant to determine the interference between the wells. The plant tested is located in the Arkansas valley near Garden City and consists of four wells which average 42 feet in depth. Table 16 is taken from the report by McCall and Davison (1939, table 4) and shows the results of their tests.
Table 16--Interference of wells in a battery-well plant (McCall and Davison, 1939, table 4)
Depth and diameter of irrigation wells--The depths of irrigation wells in this area are given in table 17 and are summarized below.
Table 17--Irrigation wells in Finney and Gray counties classified according to depth.
Most of the upland irrigation wells in Finney County range from 200 to 360 feet in depth, but a few are less than 150 feet deep. In Gray County, most of the upland wells range from 100 to 200 feet in depth, and only one well is more than 200 feet deep. Most of the irrigation wells, in the Arkansas valley in this area are only 30 to 50 feet deep, although some are 50 to 100 feet deep and a few exceed 100 feet in depth. Eighteen of the irrigation wells in the valley are less than 30 feet in depth.
The diameter of the irrigation wells in Finney and Gray counties are given in table 18 and are summarized below.
Table 18--Irrigation wells in Finney and Gray counties classified according to diameter.
The diameters of the irrigation wells range from 2 inches to 36 inches. Of the 58 upland irrigation wells for which the dimensions are known, 40 are 16 inches in diameter and 8 are 18 inches in diameter. Most of the valley irrigation wells are 16 inches in diameter, but many are 15 or 18 inches in diameter.
Types of pumps on irrigation wells--All of the upland irrigation wells and four of the valley wells are equipped with turbine pumps having from two to five stages, or bowls. The turbine pumps range in size from 4 to 10 inches, but 6- and 8-inch are the most common sizes. Some of the older upland irrigation wells owned by the Garden City Company are equipped with large old-style turbine pumps (pl. 7A). The newer turbine pumps are much smaller and generally are more efficient (pl. 7B). One upland well (128) is equipped with a submersible turbine pump (pl. 8A) in which the electric motor is housed in a water-tight compartment just above the bowls of the pump.
All but four of the irrigation wells in the Arkansas valley in this area are equipped with centrifugal pumps ranging in size from 1 1/2 to 14 inches. Most of these are of the horizontal type--only two being vertical centrifugal pumps. The most common sizes of centrifugal pumps are 4-, 5-, 6-, and 8-inch.
A few irrigation wells used to irrigate small gardens or trees are equipped with cylinder pumps powered by windmills.
Type of power used for operating irrigation wells--The types of power used to operate irrigation wells in Finney and Gray counties are given in table 19. Most of the wells are operated by electric motors using power supplied mainly by the Garden City Company. Where electricity is not available the pumps generally are powered by gasoline engines or by tractors. Most of the gasoline engines used to operate irrigation wells have been removed from old cars or combines (pl. 8B), but some are of the type built for stationary use. Two wells (488, 534) have natural-gas engines, two (wells 227 and 439 have engines using butane gas for fuel, one (well 492) has a Diesel engine, and one (well 434) is operated by a windmill.
Table 19--Types of power used for operating irrigation wells in Finney and Gray counties, Kansas.
Irrigation water pumped from streams--Pumping water from streams for irrigation is practiced to a small extent in this area, principally along Pawnee River (pl. 5A). Dams have been constructed across Pawnee River in a few places to impound the water so it can be pumped to higher ground where it is used to irrigate crops. A few attempts have also been made to pump water from Arkansas River for irrigation use. No pumpage or acreage figures were obtained for the river pumping plants.
Possibilities of Developing Additional Irrigation Supplies from WellsThe amount of water that can be pumped from an underground reservoir without causing excessive permanent lowering of the water table depends on the capacity of the reservoir and on the amount of annual recharge to the reservoir. If water is withdrawn from an underground reservoir by pumping faster than water enters it, the water levels in wells will decline and the supply eventually will be depleted. The amount of water that can be withdrawn annually from the ground-water reservoir over a long period of years without causing depletion of the available supply is termed the safe yield of the reservoir. The feasibility of developing additional water supplies from wells for irrigation in Finney and Gray counties is dependent upon the safe yield of the underground reservoir and upon other geologic, hydrologic, and economic factors.
The question of whether further irrigation is possible or practical in a specific area is of extreme importance, not only to the present irrigators but also to those persons who may contemplate investing money in an irrigation well. Overdevelopment in an irrigation area will cause lowering of the water table, thereby increasing the total pumping lift. This is important to those who own irrigation wells, for the cost of lifting water to the surface increases in proportion to the total pumping lift. The most important question to the farmer who is contemplating the construction of an irrigation well is whether or not the ground water can be developed and pumped to the surface at a cost low enough to permit a profit from the crops produced. The depth to water level determines in part the original cost of the well and the cost of operation. The height a given quantity of water must be lifted is a prime factor in determining the cost of operating a well. The economic success of an irrigation project often hinges on this point. It is generally not possible to state the limit of economical pumping lift in a given locality, for it depends on such factors as the cost of fuel for operating the pump, efficiency of the pump, kind and price of the crops being irrigated, and the skill and management of the individual. In 1902, Johnson (1902, p. 668) made the following statement:
"The economical pumping lift at Garden (Garden City, Kan.) under present conditions, can hardly be said to reach 20 feet. Under the more favorable conditions of future development and a local market this will probably not be increased by more than 50 percent. That is, 25 feet appears to be about the limit of height above the water plane at which irrigation farming from wells can profitably be conducted--at least on a commercial basis."Since this statement was made, the economical pumping lift in the vicinity of Garden City has increased more than 100 percent above the maximum figure given by Johnson, owing to modern developments in well construction, higher efficiency of modern pumps, type and increased price of crops being irrigated, and reduced cost of fuel for pumping.
The character and thickness of the water-bearing beds determine in part the original cost of constructing a well and the cost of operating the pumps after the well is completed. If the water-bearing beds are composed of somewhat fine materials, it may be necessary to gravel-pack the well which increases the original cost. If the water-bearing materials are sufficiently coarse, less expensive wells employing well screens or perforated casings without gravel packing can be constructed.
The possibilities for developing additional water supplies for irrigation in six different areas in Finney and Gray counties are discussed below.
Arkansas valley--Available data indicate that the capacity of the underground reservoir in the Arkansas valley in this area is large enough to withstand more pumping for irrigation, particularly in those parts of the valley in which there is now but little pumping. The valley area has the advantage that water is available from the alluvium and also from sands and gravels of Pliocene (Ogallala formation) and Pleistocene age beneath the alluvium. The water table in the valley is shallow (pl. 2) so that pumping lifts are low. Moreover, the conditions for recharge are more favorable in the valley than any other area in Finney and Gray counties.
Information as to the safe yield of the ground-water reservoir is obtained by a study of the relations of water levels in observation wells in the valley to the amount of pumpage. If the water levels in the wells remain stationary during a long period of pumping, it may be concluded that the rate of recharge has been approximately equal to the rate of discharge, including both natural discharge and artificial discharge by wells. If at the end of any long period the water levels return approximately to the position they had at the beginning of the period, the record of pumpage furnishes a measure of the recharge minus the natural loss. The hydrographs shown in figure 13 indicate that there has been no persistent downward trend of the water table in the heavily pumped part of the Valley in the area surrounding Garden City and Holcomb during the period from November, 1934, to December, 1942. The fluctuations of the water table in the Arkansas valley are of a seasonal type (fig. 15).
The precipitation at Garden City has averaged 6.85 inches below normal for the 9-year period from 1931 through 1939--the longest consecutive period of subnormal precipitation in the 53-year record of the station. In 1934, 1935, and 1937 the annual precipitation at Garden City was more than 10 inches below normal, and in 1939 it was 9.77 inches below normal--the four driest years since 1894. Thus, during the 9-year period the water levels in the valley declined partly as a result of below-normal precipitation and partly as a result of increased pumpage. In 1940, the precipitation was 1.28 inches above normal and in 1941 it was 6.57 inches above normal. The water levels in most of the wells in the Arkansas valley showed a net rise for each of these years. By the end of 1941 the water levels in the eight irrigation wells (fig. 13) had reached their highest levels since the records were started in 1934. The trends in water levels during the period of record indicate, therefore, that the pumpage has not exceeded the safe yield.
In 1939, the sixth driest year on record, a total of about 34,870 acre-feet of water was pumped from wells in the Arkansas valley in Finney and Gray counties. Of this amount, about 27,100 acre-feet of water was pumped from wells in the valley in Finney County to irrigate about 11,580 acres of crops. This amount of pumpage probably is considerably above the annual average. The water-level fluctuations during the period seem to indicate that the present rate of pumping is not depleting the ground-water reservoir and that some additional pumping can be undertaken without exceeding the safe yield. To prevent local overdevelopment, however, care should be taken in locating and spacing the new wells.
Conditions seem to be favorable for additional pumping from wells in several parts of the Arkansas valley in this area, and almost all of the valley in Gray County could safely withstand additional irrigation development. In 1940, there were only 22 irrigation wells in the valley in Gray County and only 1,420 acres were irrigated. There are still many acres of flat bottom land in the valley in Gray County that could be irrigated by pumping from wells if care were taken in selecting areas having favorable soils. Properly constructed shallow wells in the alluvium may be expected to yield up to 500 gallons a minute, or possibly more in local areas; yields as high as 1,500 gallons a minute could be expected from a battery of shallow wells. Deep test drilling indicates that the basal part of the Ogallala formation in this area contains a variable thickness of coarse, unconsolidated gravel capable of yielding water freely to wells (see logs of test holes 21 and 22 and pp. 163, 164). A single deep well of the proper construction may be expected to yield up to 1,500 gallons a minute. Logs of two test holes indicate that the water-bearing material in the Ogallala in this area contains enough fine sand to warrant the use of gravel-packed wells (p. 93). In some places, however, the water-bearing material might be sufficiently free from fine sand so that gravel packing the wells would not be necessary.
Throughout this part of the valley the water surface in the river generally is below the water table so that water is discharged from the ground-water reservoir into the river and leaves the area as surface flow. Lowering the water table by additional pumping would decrease the amount of ground water lost, to the river, and if the water table were lowered below the level of the river channel some of the surface flow would be added to the ground-water reservoir. Hence, additional pumping in this part of the valley, instead of depleting the ground-water supply, would aid in salvaging much of the water that now heaves the county as stream flow.
That part of the Arkansas valley in eastern Finney County from a point about 3 miles downstream from Garden City to the Gray County line also could withstand additional irrigation development. The same considerations applied to the valley in Gray County also apply to this area. The valley in eastern Finney County is much narrower, however, so that there is much less land suitable for irrigation. Logs 9 and 13 illustrate the character of the water-bearing material in this part of the valley and indicate that the known thickness of the water-bearing material ranges from about 130 feet near Pierceville to more than 210 feet in the western part of the area. At the present time there are only ten irrigation wells in this part of the valley, all but two of which are north of the river. The soils south of the river are quite sandy, and for this reason are not as favorable for irrigation as the less sandy soils north of the river.
Some additional pumping from wells for irrigation might prove successful in the valley on the south side of the river west of Holcomb. In 1939, there were only five active irrigation plants (wells 341, 342, 348, 349, and 351) in this part of the valley. Well 342 consists of a battery of ten shallow wells and is reported to yield 3,700 gallons a minute. Well 348 consists of two shallow wells and is reported to yield about 800 gallons a minute. Wells having comparable yields probably could be constructed. Preliminary test holes should provide the necessary information to determine whether a deep or shallow well should be constructed and whether or not the well should be gravel-packed.
Finney basin--The Finney basin includes the large area of shallow water north of the Arkansas valley in western Finney County. This area of shallow water extends northward to the central part of Scott County where it is known as the Modoc basin. The depth to water level in the Finney County part of the shallow-water basin is nearly everywhere less than 50 feet, and over a large part of the basin it is less than 25 feet. In 1940, there were about 100 deep irrigation wells in the shallow-water basin in Scott County, and about 50 in Finney County. Of the 50 irrigation wells in the basin in Finney County, more than 40 are situated in a belt 2 to 4 miles wide bordering the Arkansas valley. North of this there are only a few scattered wells.
Much of this large area contains land that could be successfully irrigated from deep wells. The water-bearing formations in this area (the Ogallala. formation and the undifferentiated Pleistocene deposits) have a total thickness of from about 120 feet in the western part to about 250 feet in the deepest part of the structural basin (fig. 8 BB'). The water-bearing materials range in texture from fine sand to coarse gravel, but the character and thickness of these materials vary greatly from place to place even within a short distance, so that some wells encounter more and better water-bearing materials than others (see logs 2, 3, 4, 7, and 30). Before putting down an irrigation well, several test holes of small diameter should first be drilled in order to determine whether or not saturated materials of the proper character and thickness are available. The test-hole data also will indicate whether or not gravel packing is necessary, and if not, what size screen should be used or what size perforations should be made in the casing.
The existing irrigation wells in the Finney basin range from about 150 to almost 350 feet in depth. The measured yields from these wells range from 400 to 1,770 gallons a minute with drawdowns ranging from 18.5 feet to 135 feet (table 12, p. 106). Well 24, the only active irrigation well in the northern part of the Finney basin, was drilled in 1940 and is 155 feet deep (log 30). The water level in this well is about 30 feet below land surface. During a pumping test conducted by P.H. Browne, representative of the Johnston Pump Company, the well discharged 1,770 gallons a minute with a drawdown of about 30 feet. Before drilling this well, several test holes were drilled in order to determine the best possible site for the well.
Uplands in north-central Finney County--In north-central Finney County north of the valley is a large upland area in which the depth to water level is between 50 and 100 feet (pl. 2). Very little information is available concerning the character and thickness of the water-bearing deposits in this area, but available data indicate that the saturated deposits are comparatively thin. Test hole 2 (log 2), in the southwest corner of sec. 3, T. 22 S., R. 31 W., encountered only 16 feet of water-bearing sand and gravel. An east-west geologic profile across the central part of this area (fig. 8 BB') shows that the saturated part of the unconsolidated deposits are about 160 feet thick near the Finney basin, but that they become much thinner toward the east. In the extreme eastern part of the area, all of the unconsolidated deposits lie above the water table.
Only two irrigation wells (27 and 60) have been drilled in this area. Well 27, in the westernmost part of the upland area near the Finney basin, is 199.5 feet deep, is gravel-packed, and the water level is about 76 feet below land surface. During a pumping test conducted by P.H. Browne, representative of the Johnston Pump Company, the well discharged 850 gallons a minute with a drawdown of about 34 feet. Before drilling well 27, a well was drilled about 1 mile to the north, but the water-bearing sand and gravel encountered was too thin to permit the completion of a successful well. Well 60, in the easternmost part of the upland area, is 118 feet deep and the water level is about 70 feet below the land surface. The well is reported to yield 300 gallons a minute.
From the foregoing facts, it may be concluded that the western part of the upland area in north-central Finney County is more favorable for irrigation development than the eastern part, and that the success or failure of an irrigation well in this area depends largely on local conditions. The drilling of several test holes of small diameter before putting down the final well probably is more important in this area than in any other area discussed.
Uplands in northeastern Gray County--In the part of northeastern Gray County northeast of the 100-foot depth to water line (pl. 2) the water table is everywhere less than 100 feet below the surface, and in the valley of Buckner creek it is less than 25 feet below the surface. The relief of the surface in the vicinity of Buckner creek and its tributaries is too great for irrigation; however, much of the land surrounding the valleys might be favorable for irrigation. Wells in this area obtain water from sand and gravel in the Ogallala formation, the character and thickness of which is indicated by the logs of two test holes (17 and 18) and the north-south geologic profile in figure 9 (DD'). According to available data, the Ogallala attains its maximum thickness--about 250 feet--in the southern part of this area and thins to 100 feet--or less in the northeastern part.
In 1939 there was only one active irrigation well (402) in this area, in sec. 6, T. 24 S., R. 27 W. This well is gravel-packed, is 105 feet deep, and the depth to water level is about 65 feet. During a pumping test conducted by Kenneth D. McCall, engineer, Division of Water Resources, Kansas State Board of Agriculture, the well discharged 1,020 gallons a minute with a drawdown of 13.2 feet.
Although the conditions here are not as favorable as in other areas, it is believed that irrigation from wells could be practiced successfully in parts of the northeastern Gray County area. Additional wells of proper construction in favorable localities could be expected to yield 500 to 1,500 gallons a minute. Because of the variable nature of the water-bearing materials in the Ogallala formation, it would be necessary to drill test holes before locating any large wells.
West-central Gray County--Another area favorable for additional irrigation development is that south of the sand hills and north of Crooked Creek in west-central Gray County. This is a relatively flat upland area in which the depth to water level ranges from about 60 feet to about 115 feet. A test hole drilled in the northeast corner of sec. 31, T. 27 S., R. 30 W., encountered 404 feet of unconsolidated material (undifferentiated Pleistocene deposits and Ogallala formation) above the Dakota formation (see log 24). Almost 200 feet of this material consisted of saturated sand and gravel. The Pleistocene deposits and the Ogallala formation thicken toward the north and west in this area (fig. 9 CC').
In 1940, there were six irrigation wells (492, 493, 494, 496, 515, and 516) in this area (pl. 2). All of these wells are equipped with turbine pumps powered by gasoline or Diesel engines, and most of them are gravel packed. The wells are 110 to 165 feet deep, and the depth to water level in them ranges from about 64 feet to about 110 feet. The yields of these wells range from about 800 to 1,100 gallons a minute.
Well 496 is typical of the wells that can be developed in this area. It is a gravel-packed well 135 feet deep in which the water level is 68 feet below the surface. Coarse water-bearing gravel was reported between the depths of 72 and 135 feet. During a pumping test conducted in 1940 by Kenneth D. McCall, engineer, Division of Water Resources, Kansas State Board of Agriculture, this well yielded 875 gallons a minute with a drawdown of 11.3 feet after 4.5 hours of pumping.
The ground-water reservoir beneath this area is large enough to withstand additional pumping from wells. Periodic measurements of the water level in well 515 in the southern part of the area have been made since December, 1939. From December 14, 1939, to December 4, 1940, the water level in well 515 showed a net rise of 1.08 feet, and from December 4, 1940, to December 26, 1941, there was a net rise of 0.19 foot; thus, there has been no decline in the water table in this area as a result of the pumping of water from irrigation wells. Irrigation development could safely be expanded in this area without endangering the ground-water supply. Properly constructed deep wells could be expected to yield 800 to 1,000 gallons a minute without excessive drawdown. In local areas as much as 1,500 gallons a minute probably could be developed from a single well.
Crooked Creek area--In the area occupied by Crooked Creek and its tributaries in southern Gray County the depth to water level is from less than 25 feet to 100 feet (pl. 2). A test hole drilled in the northwest corner of sec. 34, T. 29 S., R. 28 W., encountered 164.5 feet of unconsolidated silt, sand, and gravel of Pleistocene age above the Cretaceous bedrock. About 62 feet of this consisted of water-bearing sand and gravel, the thickness of which probably increases toward the west and northwest.
The character and thickness of the water-bearing deposits in southern Gray County are favorable for the development of irrigation wells of moderate yields. The surface relief in this area, however, is in general too great to permit successful irrigation. In 1940, there was only one irrigation well (534) in southern Gray County. It is 138 feet deep and the depth to water level is about 99 feet. The well penetrated only about 15 feet of water-bearing sand and gravel--the rest of the material below the water table consisted of relatively impermeable silt, clay, and caliche (see log 56). During a pumping test conducted by Kenneth D. McCall, engineer, Division of Water Resources, Kansas State Board of Agriculture, the well yielded 475 gallons a minute with a drawdown of 25.9 feet.
Kansas Geological Survey, Finney and Gray County Geohydrology|
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Web version April 2002. Original publication date Dec. 1944.