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Source-linked reports with geographic coverage including Nebraska.

At least 361 records · Page 20Linked to original sources
USGS1960

Geology and ground water in the Platte-Republican Rivers watershed and the Little Blue River basin above Angus, Nebraska, with a section on chemical quality of the ground water

This report describes an area of about 7,300 square miles in south-central Nebraska. Approximately one-fourth of the area, largely at its east end, consists of an undissected southeastward-sloping upland plain and is almost wholly irrigable; the remainder is in various stages of dissection and only parts of it are suitable for irrigation. Although some of the deeper lying bedrock formations are potential sources of water supply, they are not likely to be tapped in the near future because abundant supplies are available at shallower depth from semiconsolidated and unconsolidated deposits. The Ogallala formation of Tertiary (Pliocene) age consists of gravel, sand, silt, and volcanic ash, some layers of which are partly cemented. It was deposited by eastward-flowing streams, which formed a constructional plain above a surface into which the streams had previously eroded broad valleys. In turn, valleys were cut into the surface of the Ogallala before the overlying deposits of gravel, sand, silt, and clay of Quaternary (Pleistocene) age were laid down, also forming a constructional plain. During Recent time, streams have dissected the older deposits and have deposited thin alluvium in their valleys; also, several parts of the area have become mantled by wind-deposited sand. Because during Tertiary and Quaternary time the area repeatedly was the site of deposition and erosion, the thickness of all the stratigraphic units differs markedly from place to place. In general, however, the Ogallala formation thins eastward and in the central and eastern parts of the area is overlain by the eastward-thickening deposits of Pleistocene age. The maximum thickness of the Ogallala formation is about 500 feet, and the maximum thickness of the Pleistocene deposits is a little more than 300 feet. Each thins to a featheredge and is completely absent in parts of the area. The water-bearing part of the combined Tertiary and Pleistocene deposits is considered to be a single zone of saturation because the ground water, as it percolates southeastward beneath the area, moves out of the Tertiary and into the Quaternary deposits without apparent hindrance. The water that enters the area as underflow from the west is augmented within the area by water that infiltrates from the land surface. The principal sources of irrigating water are precipitation, seepage from canals and reservoirs, and applied irrigation water. Except for the water withdrawn through wells or discharged by natural processes where valleys have been cut into the zone of saturation, ground water leaves the area as underflow into the Platte River valley on the north, the Blue River drainage basin on the east, or the Republican River valley on the south. Part of the water used for irrigation and watering livestock and all the water used in rural and urban homes, in public buildings, and for industrial purposes is obtained from wells, To date (1952) there is no indication that the supply of ground water is being depleted faster than it is being replenished; instead, studies indicate that greater quantities can be withdrawn without causing an excessive decline of the water table. An increase of ground-water withdrawals to a sustainable maximum, however, will be possible only if the points of withdrawal are scattered fairly uniformly. It is estimated that annual withdrawals per township should not exceed 2,100 acre-feet where infiltrating precipitation is the only source of recharge, or 3,000 acre-feet where other sources of recharge are significant. Although perennial withdrawals of this amount could be sustained indefinitely, they would cause some lowering of the water table and eventually a decrease in the amount of water discharged from the area by natural means. The ground water is of the calcium bicarbonate type. In much of the area it is hard or very hard, and in places it contains excessive amounts of iron. In all other respects the water is chemically suitable for domesti

Nebraska↗
USGS1957

Water levels in observation wells in Nebraska during 1956

The Objective of the observation-well program in Nebraska is to provide an evaluation of the status of the ground-water supplies. Many uses tor water-level data are known but not all potential uses can be foreseen. Among the important uses are the following: (1) To indicate the status of ground water in storage or in transit and the availability or supplies. (2) To show the trend of ground-water supplies and the outlook tor the future. (3) To estimate or forecast the base flow of streams. (4) To indicate areas in which the water level is approaching too close to the land surface (water-logging) or is receding toward economic limits of lift or toward impairment by water of poor quality. (5) To provide long-term evidence for evaluating the effectiveness of land-management and water-conservation programs in relation to water conservation actually effected, and for use in basin or "watershed" studies. (6) To provide long-term continuous records to serve as a framework to which short-term records collected during intensive investigation may be related. The water level in an observation well functions as a gage to indicate the position or the water table. The water table is defined as the upper surface of the zone of saturation except where that surface is formed by overlying impermeable materials. The water table is also the boundary between the zone of saturation and the zone of aeration. It is not a level surface but is a sloping surface that has many irregularities, and it often conforms in a general way to the land surface. The irregularities are caused by several factors. In places where the recharge to the ground-water reservoir is exceptionally large, the water table may rise to form a mound from which the water slowly spreads. Depressions or troughs in the water table indicate places where the ground water is discharging, u along streams that are below the normal level it the water table, or indicate places where water is being withdrawn by wells or vegetation. The several factors that influence the water table vary in fact and amount from time to time because of changes in weather and the water requirements or vegetation and man; thus, the water table is nearly always rising or falling. The fluctuations or the water table are shown by the changes in water levels in wells. Thus, the rate and amount of the fluctuation of the water table can be ascertained by observing the water levels in wells, and the magnitude or the several factors effecting the position of the water table can be interpreted by analyzing the water-level data. Water-level measurements are given, in this report, in feet below the land surface at the well site. Water levels that are above land surface are preceded by a plus (+) sign in the tables, whereas those below land surface have no sign but are understood to be minus (-). The words "land-surface datum" are abbreviated "lsd'' in some places in tables of this report. The altitude above mean sea level (msl) of the land surface at many of the well sites has been determined and is included in the tables or this report. Twenty-eight observation wells in Nebraska are equipped with recording gages. Each recording gage produces a continuous graph of water-level fluctuations in the well. Only the lowest water level on the last day of record in each month, as recorded by the gage, is given in this report; the complete record is on file in the office of the U.S. Geological Survey in Lincoln, Nebr.

Nebraska↗
USGS1956

Water levels in observation wells in Nebraska during 1955

The objective of the dbservation-well program in Nebraska is to provide an evaluation of the status of the ground-water supplies. Many uses for water-.level data are known but not all potential uses can be forseen. Among the important uses are the following: To indicate the status of ground water in storage or in transit and the availability of supplies. To show the trend of ground-water supplies and the outlook for the future. To estimate or forcast the base flow of streams. To indicate areas in which the water level is approaching too close to the land surface (water-logging) or is receding toward economic limits of lift or tow rd impairment by water of poor quality. To provide long-term vidence for evaluating the effectiveness of land-management and water...0 nservation programs in relation to water conservation actually of ected, and for use in basin or "watershed" studies. To provide longterm ontinuous records to serve as a framework to which short-term records collected during intensive investigation may be related. The water level in an observation well functions as a gage to indicate the position of the water table o The water table is defined as the upper surface of the zone of saturation except where that surface is formed by overlying impermeable materials. The water table is also the boundary between the zone of saturation and the zone of aeration. It is not a level surface but is a sloping surface that has many irregularities, and it often conforms in a general way to the land surface. The irregularities are caused by several factors. In places where the recharge to the ground-water reservoir is exceptionally large, the water-table may rise to form a mound from which the water slowly spreads. Depressions or troughs in the water table indicate places where the ground water is discharging, as along streams that are below the normal level of the water table, or indicate places where water is being withdrawn by wells or vegetation. The several factors that influence the water table vary in fact and amount from time to time because of changes in weather and the water requirements of vegetation and man; thus, the water table is nearly always rising or falling. The fluctuations of the water table are shown by the changes in water levels in wells. Thus, the rate and amount of the fluctuation of the water table can be ascertained by observing the water levels in wells, and the magnitude of the several factors effecting the position of the water table can be interpreted by analyzing the water—level data. Water-level measurements are given, in this report, in feet below the land surface at the well site. Water levels that are above land surface are preceded by a plus (+) sign, whereas those below land surface have no sign but are understood to be minus (-). The words "land-surface datum" are abbreviated "lsd" in tables of this report. The altitude above mean sea level (msl) of the land surface at many of the well sites has been determined and is included in the tables of this report. Lower case letters which appear in the table of water level measurements indicate the following: 6', nearby well pumped recently; f, dry; g, measured by outside agency; and j, frozen. Twenty-.six observation wells in Nebraska are equipped with recording gages. Each recording gage produces a continuous graph of water-level fluctuations in the well. Only the lowest water level on the last day of record in each month, as recorded by the gage, is given in this report; the complete record is on file in the office of the U. S. Geological Survey in Lincoln, Nebr.

Nebraska↗