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USGS1971

Summary of floods in the United States during 1966

This report describes the outstanding floods in the United States during 1966. The four most destructive floods occurred during March-April in the Red River of the North basin in northwestern Minnesota, during April-May in northeastern Texas, in August, in east-central Nebraska, and in December, in the Southwestern United States. For the second consecutive year, there was severe flooding in the Red River of the North basin in Minnesota during ,the spring snowmelt period. Unseasonally warm temperature caused rapid melting of a heavy snow cover, with water equivalent ranging from 5 to 7 inches, which covered .the northern two-thirds of the basin. Peak discharges were maximum of record at three gaging sites having periods of record ranging from 20 to 30 years, ,and peak discharges exceeded 50-year floods at nine sites. Damage from the flood was estimated at $10 million. In the period April 22-29, from 20 to 26 inches of rain fell in parts of the Sabine River basin in northeastern Texas. and high rates of runoff occurred from the headwaters of the Sulphur River southward .to the Trinity River basin. Flood damage was estimated at $12 million, and at least 25 persons lost their lives. Severe floods occurred along the Loup River ,and its tributaries in east-central Nebraska on August 12-14. The .peak discharge at nearly all gaging stations in the flood area exceeded the previous maximum of record. The floods we re caused by heavy rains of from 13 to 17 inches in about 24 hours. The storm was the most widespread in the area since 1896 and may have exceeded the area of the 1896 storm. The floods were unusual because of the consistently high discharges throughout a large flood area. Flood damage was estimated at $11 million. In early December a storm moved eastward from the Pacific coast in southern California into Southwestern United States. Intense precipitation occurred around the mountain ranges of south-central California and in and extending from southeastern Nevada across the southwestern corner of Utah to the Grand Canyon and southward to the mountains of central Arizona. Discharges on many streams exceeded the previous maximums known, and the flood was particularly damaging because of the large area involved. In .addition to these four floods, 19 others of lesser magnitude are considered important enough to be included in this annual summary.

Water Supply Paper↗
USGS1968

Water data for metropolitan areas: A summary of data from 222 areas in the United States

Expansion of metropolitan areas poses persistent problems in management of the hydrologic environment. Adequate hydrologic data are prerequisite to proper planning and engineering design of urban environments. Some such data are available and are tabulated for each Standard Metropolitan Statistical Area in the United States. Information for each area consists of (1) data on size and population, (2) a short statement of the hydrology of the area, (3) a summary of current data-collection activities in the area, (4) a listing of current U.S. Geological Survey investigational projects in the area, and (5) a short listing of reports relating to the hydrology of the area.

Water Supply Paper↗
USGS1969

Hydrogeology of the Scioto River Valley near Piketon, south-central Ohio

A systematic study was made of one of Ohio's principal aquifers, a sand and gravel outwash in the Scioto River Valley, to determine the feasibility of developing a ground-water supply of 20 million gallons per day at a site near Piketon. The first part of the study was spent in determining the thickness and physical properties of the sand and gravel aquifer and in drilling test wells to determine the best site for the supply wells. The second part of the investigation was an aquifer infiltration test to determine the hydraulic properties of the aquifer and the conditions of stream recharge. A well 83 feet deep was drilled on the flood plain and was pumped for 9 days at the rate of 1,000 gallons per minute. Tile effect on the hydrologic system during and after the pumping was determined by measuring the water levels in an array of deep and shallow observation wells and in 8 drive-point wells installed in the bed of the river. Seldom have more comprehensive data been collected showing the effects of pumping on a natural, unconfined, hydrologic system. From these data were calculated the coefficient of transmissibility (215,000 gallons per day per foot) and the rate of streambed infiltration (0.235 million gallons per day per acre per foot). The aquifer was tested near the end of a long drought; so the ground-water levels and the river stage were very nearly following a level trend. Because the ground-water levels were essentially unaffected by extraneous influences, the test data are probably as precise and uncomplicated as is practical to obtain in the field. These data proved to be valid for use as design criteria for the location, spacing, and construction of four supply wells. The third part of the investigation was the testing and quantitative evaluation of the four supply wells before they were put into service. The wells were found to perform about as predicted, indicating that the hydraulic properties of the aquifer, as determined by standard methods, are fairly representative.

Ohio↗
USGS1969

Factors initiating phytoplankton blooms and resulting effects on dissolved oxygen in Duwamish River estuary, Seattle, Washington

Phytoplankton productivity, standing stock, and related environmental factors were studied during 1964-66 in the Duwamish River estuary, at Seattle, Wash., to ascertain the factors that affect phytoplankton growth in the estuary; a knowledge of these factors in turn permits the detection and evaluation of the influence that effluent nutrients have on phytoplankton production. The factors that control the concentration of dissolved oxygen were also evaluated because of the importance of dissolved oxygen to the salmonid populations that migrate through the estuary. Phytoplankton blooms, primarily of diatoms, occurred in the lower estuary during August 1965 and 1966. No bloom occurred during 1964, but the presence of oxygen-supersaturated surface water in August 1963 indicates that a bloom did occur then. Nutrients probably were not the primary factor controlling the timing of phytoplankton blooms. Ammonia ,and phosphate concentrations increased significantly downstream from the Municipality of Metropolitan Seattle's Renton Treatment Plant outfall after the plant began operation in June 1965, and concentrations of nitrogen and phosphorus were relatively high before operation of the Renton Treatment Plant and during nonbloom periods. The consistent coincidence of blooms with minimum fresh-water discharge and tidal exchange during August throughout the study period indicates that bloom timing probably was controlled mostly by hydrographic factors that determine retention time and stability of the surface-water layer. This control was demonstrated in part by a highly significant correlation of gross productivity with retention time (as indicated by fresh-water discharge) and vertical stability (as indicated by the difference between mean surface and mean bottom temperatures). The failure of a bloom to develop in 1964 is related to a minimum fresh-water discharge that was much greater than normal during that summer. Hydrographic factors are apparently important because, as shown by studies of other estuarine environments by other workers, phytoplankton production increases when the zone of vertical turbulent mixing is not markedly deeper than the compensation depth. Phytoplankton cells produced in the surface waters sink, thereby contributing oxidizable organic matter to the bottom saline-water wedge. The maximum BOD (biochemical oxygen demand) in this bottom wedge occurs in the same section of the estuary and ,at the same time as the maximum phytoplankton biomass (as indicated by chlorophyll a) and minimum DO (dissolved oxygen). Other sources of BOD occur in the estuary, and conditions of minimum discharge and tidal exchange assist in reducing DO. Nonetheless, the highly significant correlation of chlorophyll a with BOD throughout the summer indicates that respiration and decomposition of phytoplankton cells is dearly an important contributor of BOD. Increases in the biomass and resultant B0D of blooms because of increased effluent nutrients presumably would further decrease the concentration of DO. This possible effect of effluent nutrients was evaluated by laboratory .bioassays and by a comparison of mean annual biomasses in the estuary. A green algal population in vitro did increase in response to added effluent nutrients; however, the available field data suggest that a 46-percent increase in effluent discharge between 1965 and 1966 did not increase the estuary's phytoplankton biomass significantly.

Water Supply Paper↗
USGS1969

Estuarine studies in upper Grays Harbor, Washington

Improved management of the water resources of Grays Harbor, Wash., requires more data on the water quality of the harbor and a better understanding of the influences of industrial and domestic wastes on the local fisheries resources. To provide a more comprehensive understanding of these influences, the U.S. Geological Survey joined other agencies in a cooperative study of Grays Harbor. This report summarizes the Survey's study of circulation patterns, description of water-quality conditions, and characterization of bottom material in the upper harbor. Salt water was found to intrude at least as far as Montesano, 28.4 nautical miles from the mouth of the harbor. Longitudinal salinity distributions were used to compute dispersion (diffusivity) coefficients ranging from 842 to 3,520 square feet per second. These values were corroborated by half-tidal-cycle dye studies. The waters of the harbor were found to be well mixed after extended periods of low fresh-water flow but stratified at high flows. Salinity data were used lo define the cumulative 'mean age' of the harbor water, which may be used to approximate a mean 'flushing time.' Velocity-time curves for the upper harbor are distorted from simple harmonic functions owing to channel geometry and frictional effects. Surface and bottom velocity data were used to estimate net tidal 'separation' distance, neglecting vertical mixing. Net separation distances between top and bottom water ranged from 1.65 nautical miles when fresh-water inflow was 610 cubic feet per second to 13.4 miles when inflow was 15,900 cubic feet per second. The cumulative mean age from integration of the fresh-water velocity equation was about twice that obtained from the salinity distribution. Excursion distances obtained with dye over half-tidal cycles exceeded those estimated from longitudinal salinity distributions and those obtained by earlier investigators who used floats. Net tidal excursions were as much as twice those obtained with floats. The carbon content of bottom materials was related to channel fine material: C= 0.315+0.0238 F where C is in percent by dry weight, and F is percent by weight finer than 0.062 millimeter. Carbon content was low upstream and downstream of the upper harbor area, and high in the Cow Point-Rennie Island reach. The high-carbon-content reach coincides with the general area of a dissolved-oxygen sag. The logarithm of the fresh-water discharge gave a high degree of correlation with daily maximum specific conductance at Cosmopolis. The regression equation is: Kc max---- 76.4-- 17.7 logl0 Qf where Kc max is in millimhos at 25 ? Celsius (centigrade), and Qf is the estimated daily fresh-water discharge, in cubic feet per second. Dissolved oxygen is the most critical water-quality parameter in Grays Harbor. At Cosmopolis, the daily minimum dissolved oxygen content, DOc min, correlated well with discharge and tidal range, delta H. The regression equation relating the variables is: DOc min---- 6.03 + 0.00096 Qf - 0.291 delta H in which DOc min is in milligrams per liter and delta H is in feet. The upper harbor was found to contain 250 million cubic feet less water than average during the critical low-flow period, on the basis of the frequency distribution of predicted tides. About 78,000 pounds of dissolved oxygen is thus unavailable for oxidation of waste during summer.

Water Supply Paper↗
USGS1972

Physical, chemical, and biological aspects of the Duwamish River Estuary, King County, Washington, 1963-67

This report describes the significant results to 1967 of a comprehensive study that began in 1963 to evaluate what changes take place in an estuary as the loads .of raw and partially treated industrial and municipal wastes are replaced by effluent from a secondary treatment plant. The study area is the Duwamish River estuary, about 18.3 river kilometers long. At mean sea level the estuary has a water-surface area of about 1 square mile and a mean width of 440 feet. At the lowest and highest recorded tides, the volume of the estuary is about 205 and 592 million cubic feet, respectively. The estuary is well stratified (salt-wedge type) at fresh-water inflows greater than 1,000 cfs (cubic feet per second), but when inflow rates are less than 1,000 cfs the lower 5.6 kilometers of the estuary grades into the partly mixed type. The crosschannel salinity distribution is uniform for a given location and depth. Salinity migration is controlled by tides and fresh-water inflow. At fresh-water inflow rates greater than 1,000 cfs, water in the upper 8.4 kilometers of the estuary is always fresh regardless of tide. At inflow rates less than 600 cfs and tide heights greater than 10 feet; some salinity has been detected 16.1 kilometers above the mouth of the estuary. Studies using a fluorescent dye show that virtually no downward mixing into the salt wedge occurs; soluble pollutants introduced at the upper end of the estuary stay in the surface layer (5-15 ft thick). On the basis of dye studies when fresh-water inflow is less than 400 cfs, it is estimated that less than 10 percent of a pollutant will remain in the estuary a minimum of 7 days. Longitudinal dispersion coefficients for the surface layer have been determined to be on the order of 100-400 square feet per second. Four water-quality stations automatically monitor DO (dissolved oxygen), water temperature, pH, and specific conductance; at one station solar radiation also is measured. DO concentration in the surface layer decreases almost linearly in a downstream direction. Minimum DO concentration in the surface layer is usually greater than 4 rag/1 (milligrams per liter). The smallest DO values are consistently recorded in the bottom layer at the station 7.7 kilometers above the mouth; monthly means of less than 3 mg/1 of DO have occurred at this point. Manual sampling shows that the DO sag in the bottom layer oscillates between 7.7 and 10.4 kilometers above the mouth of the estuary. Multiple-regression analysis shows that the surface DO content can be estimated from the fresh-water inflow and water temperature. Tidal exchange and fresh-water inflow indirectly control the bottom DO content. Information available from previous studies failed to indicate a progressive decrease in DO content during the period 1949-56, but data from the present study suggest a slight general decrease in the annual minimum DO concentrations in both the upper and lower layers. Average nitrate concentration in fresh water at station 16.2 has increased progressively since 1964, by amounts greater than those which can be attributed to the Renton Treatment Plant, 4.3 kilometers upstream from station 16.2. The BOD (biochemical oxygen demand) in both surface and bottom layers is generally less than 4 rag/1 of oxygen, but values greater than 6 rag/1 have been measured during a period of phytoplankton bloom. Phytoplankton blooms can occur during periods of minimum tidal exchange and fresh-water inflows of less than 300 cfs if solar radiation and water temperature are optimum. Nutrients (nitrogen and phosphorus compounds) do not control the occurrence of a bloom, because sufficient quantities of these nutrients are always present. Nutrients in the treated effluent may increase the biomass of the bloom. Trace-element studies have not defined any role that these elements may play in algal growth. The inflowing fresh water contains principally calcium and bicarbonate and has a dissolved-solids content ra

Water Supply Paper↗
USGS1972

Measurement of salt-wedge excursion distance in the Duwamish River Estuary, Seattle, Washington, by means of the dissolved-oxygen gradient

The Duwamish River estuary has been the object of a series of comprehensive studies undertaken to predict the effects of the changing character of waste-water inputs on the water quality of the estuary. This report discusses the fresh- and salt-water relations of the estuary. The distance that the salt-water wedge in the estuary moves upstream and downstream with the tide is measured by a method that utilizes the persistence of the longitudinal gradient of dissolved oxygen in the salt water of the wedges. The method, though unorthodox, can serve as an independent check on any other measurements of tidal-excursion distance. Typical values obtained were a 1-kilometer excursion for a 1.3-meter tide range and a 3-kilometer excursion for a 3-meter tide range. This method of tracing the water movement seems to work because of two unusual aspects of the Duwamish River estuary: (1) the channel configuration is simple and well-suited to synoptic measurement and (2) the physical properties of the entering salt water are nearly constant.

Water Supply Paper↗
USGS1972

Movement and dispersion of soluble pollutants in the Northeast Cape Fear Estuary, North Carolina

This report presents the results of a fluorescent-dye-tracing study to determine the concentrations of a pollutant that would be present in the Northeast Cape Fear Estuary at various rates of continuous waste injection and freshwater inflow. Rhodamine WT dye was introduced into the estuary at a constant rate over a 24.8-hour period (two tidal cycles) at a point 6.4 miles upstream from the mouth in Wilmington, N.C., and concentrations were monitored at several selected sections in the tide-affected part of the river for 17 days. The range between high and low tide in this reach of the estuary averages at-rut 3.5 feet, and there is usually strong flow in both directions. Results of the dye study indicate that if a pollutant were injected at a rate of 100 pounds per day under the conditions of relatively low inflow existing' at the time, concentrations would ultimately build up to 20 micrograms of dye per liter of water 1,000 feet downstream. The flushing time during the study is estimated to be 17 days. These results are extrapolated to include periods of lower or higher inflow. For example, at average intervals of 10 years, it is estimated that inflow is so low that 100 days are required for a pollutant to travel the 6.4 miles from the point of waste release to the mouth of the river. Under these conditions it is expected that 1,000 feet downstream from the point of waste discharge, daily maximum concentrations will average about 130 micrograms per liter for each 100 pounds of pollutant injected per day. Results of a continuous discharge measurement of flow made by current meter during a complete tidal cycle are presented as a part of this report. Data from this measurement and other evidence indicate that net upstream flow in the estuary is possible over a period of several days.

North Carolina↗
USGS1972

Determination of mass balance and entrainment in the stratified Duwamish River Estuary, King County, Washington

During a study of the effects of waste-water input on the stratified Duwamish River estuary, intensive water-velocity and salinity measurements were made in both the lower salt wedge and the upper fresher water layer for tidal-cycle periods. The net movement of water and salt mass past a cross section during a tidal cycle was determined from integration of the measured rates of movement of water and salt past the section. The net volume of water that moved downstream past the section during the cycle agreed with the volume of fresh-water inflow at the head of the estuary within (1) 3.8 and 7.2 percent, respectively, for two studies made during periods of maximum and minimum tidal-prism thickness and identical inflow rates .of 312 cfs (cubic feet per second), and (2) 15 percent for one study made during a period of average tidal-prism thickness and an inflow rate of 1,280 cfs. For the three studies, the difference between salt mass transported upstream and downstream during the cycles ranged from 0.8 to 19 percent of the respective mean salt-mass transport. Water was entrained from the .salt-water wedge into the overlying layer of mixed fresh and salt water at tidal-cycle-average rates of 30 and 69 cfs per million square feet of interface for the inflow rates of 312 cfs, and 99 cfs per million square feet of interface for an inflow rate of 1,280 cfs. At a constant inflow rate, the rate of entrainment of salt-wedge water in the Duwamish River estuary more than doubled for a doubling of tidal-prism thickness. It also doubled for a quadrupling of inflow rate at about constant tidal-prism thickness.

Water Supply Paper↗
USGS1969

Water in the Kahuku area, Oahu, Hawaii

The Kahuku area comprises the north end of the Koolau Range and its bordering coastal plain. This part of the range is less deeply eroded than oth3r parts, and except for long, narrow valleys and cliffs near the shore, it has retained the general shape of the original volcanic dome. A 21/2-mile-wide dike zone of parallel and subparallel dikes along the crest is the remnant of the fissure zone of eruption. Outcrops are mostly permeable lava flows of the Koolau Volcanic Series, which are intruded by dikes inside the dike zone and are free of dikes outside it. The lava flows constitute main aquifers, and water bodies in them are called dike water inside the dike zone and basal water outside it. Dikes, because they are less permeable than the lava flows they intrude, impound ground water, thereby controlling its movement, discharge, and storage. The top of the dike-impounded water is at an altitude of at least 1,000 feet near the south end of the Kahuku area. Dike water is discharged as leakage, the amount of which fluctuates in response to changes in storage, as flow into streams, where they intersect saturated rock, and as underflow to the basal-water body. Basal water occurs on either side of the dike zone, which forms both a structural and hydrologic boundary. It is artesian on the windward side wherever it underlies the coastal plain, and the altitude of water levels ranges from 7 to 22 feet. Leeward of the dike zone, basal water occurs only under water-table conditions because of the near absence of a coastal plain, and the altitude of water levels ranges from less than 1 foot to about 3 feet. The quality of dike water is excellent except near the north end. where it is slightly contaminated by infiltration of irrigation water that contains as much as 1,200 mg/1 (milligrams per liter) chloride. Irrigation water is also a source of contamination of the basal-water body. The major contaminant, however, is sea water, which underlies the basal-water body. In the Kahuku subarea--where pumpage from the basal-water body is greatest--sea-water contamination is a major concern. Natural contamination by encroaching sea water extends more than 2 miles inland in the Waimea-Kawela subarea and generally precludes development of large quantities of basal water. At low altitudes where the perennial flow is small, all streams are intermittent except Kaluanui and Kamananui. Some streams are perennial in their upper reaches because of persistent rainfall, and some are perennial in their middle reaches owing to the discharge of dike water; however, most flows are small in the lower reaches because most of the flow has infiltrated into the ground-water reservoir. For these reasons, streamflow cannot be economically developed and is not a reliable source of water supply. Average rainfall is about 240 mgd (million gallons per day). Of this amount, about 220 mgd is in the mountains. On .the basis of a rainfall input of 220 mgd and estimates of stream runoff and evapotranspiration, ground-water flow is estimated to be 85 mgd, a figure which compares favorably with estimates based on analyses of pumping-test data. Of this amount, an average of 30 mgd is discharged by wells and the remaining 55 mgd is eventually discharged to the sea by underflow or to the atmosphere by evapotranspiration. The most promising areas for developing basal water are in the Hauula and Laie subareas, where draft is low and ground-water flow is high. The Waimea-Kawela subarea is not promising owing 'to low ground-water flow even though draft is low. Least promising for development is in the Kahuku subarea where an overdeveloped condition prevails in which draft for sugarcane irrigation exceeds the ground-water flow. The development of dike water is promising in the Waimea-Kawela subarea where ground-water flow greatly exceeds the draft.

Water Supply Paper↗
USGS1970

Correlative estimates of streamflow in the upper Colorado River basin

Most hydrologic analyses, whether for appraisal of the water resource, feasibility of a particular development, design of a system of operation, assessment of gains or losses from acts of man or natural changes, or almost any other use, require the extension in time of some streamflow records. In the Upper Colorado River Basin, streamflow records have been extended by various agencies from time to time to fulfill their individual needs, resulting in different estimates of flow for the same point and time. The purpose of this report is to provide correlative estimates of monthly mean discharge at discontinued streamflow gaging stations so that all users will have access to a single set of data. Estimates of monthly mean discharge for periods other than the period of actual record are given for certain discontinued streamflow gaging stations. The stations selected were discontinued in recent years, but they have a sufficient length of record to permit development of a meaningful correlation with the records for a nearby long-term gaging station. Where possible, estimates of monthly mean discharge are made to provide a complete record, estimated or measured, from 1930 to 1965. However, where the long-term gaging station record encompasses a shorter period, the estimates cover only that shorter period. Estimates for periods prior to 1930 were not made, although these may be computed for a few stations. Lack of a related long-term gaging-station record prevented the extension of records at many discontinued stations. The area covered in this report (fig. 1) is that defined in the Colorado River Compact of 1922, as the Upper Basin "those parts of the States of Arizona, Colorado, New Mexico, Utah, and Wyoming within and from which waters naturally drain into the Colorado River System above Lee Ferry," 1 but excluding "all parts of said States located without the drainage area of the Colorado River System which are now and shall hereafter be beneficially served by waters diverted from the System above Lee Ferry" (Wilbur and Ely, 1948, p. A18).

Colorado River Basin↗
USGS1968

Geology and ground-water resources of the lower Bighorn Valley, Montana

The Bighorn River has incised a deep, broad valley in Cretaceous strata along its 65-mile lower reach below the mouth of Bighorn Canyon in south-central Montana. It ceased downcutting at six different levels 100-200 feet apart, widening its flood plain and alluviating each level with about 30 feet of sandy gravel. These deposits are the only economic source of ground water in large areas of the valley where the underlying bedrock consists of relatively impermeable shale to great depths. Ground water in the alluvium is hard and in the irrigated lowlands is highly mineralized at those places where drainage is slow and discharge by evapotranspiration is great. Three bedrock sandstone aquifers are present at moderate depths along three separate reaches of the valley. The sandstones yield soft, moderately to highly mineralized water that contains a high percent sodium. Wells in alluvial gravel of the irrigated lowlands can yield 100 gallons per minute at many places because the alluvium is fairly permeable and is readily recharged by infiltration of applied irrigation water, canal seepage, and ground water moving into the lowlands from the alluvium of tributary coulees. Seepage from the Two Leggins Canal in the central area probably is large. Alluvial gravel deposits have been mantled by thick alluvial and colluvial deposits of silty clay or silt that thin riverward. These fine-grained deposits drain slowly and confine ground water in alluvial gravel under artesian pressure at many places in the irrigated lowlands of the central and southern areas. The piezometric surface is close to the land surface at many places in the central area, and capillary rise and evapotranspiration in waterlogged ground has produced agriculturally harmful alkali deposits. Waterlogging of presently irrigated land in the central area will become more widespread if irrigation is extended to higher terraces to the west unless drainage ditches are installed along the base of high-terrace alluvium to intercept increased seepage and spring discharge. Additional provisions also may be required to intercept water moving through the alluvium of coulees.

Water Supply Paper↗
USGS1969

Feasibility study of the use of the acoustic velocity meter for measurement of net outflow from the Sacramento-San Joaquin Delta in California

A reliable measure of the fresh-water outflow from the Sacramento-San Joaquin delta is needed for the operation of the California Water Project and for the evaluation of the interrelated water problems of the delta and San Francisco Bay regions. The Chipps Island channel, immediately downstream from the confluence of the Sacramento and San Joaquin Rivers, is the most promising site for this flow measurement, but the conventional techniques used for evaluating steady flows cannot be employed there because the channel reach is in the tidal zone, and reversals of flow occur during each tidal cycle. Net outflows, which may be as little-as 2,000 cubic feet per second must necessarily be computed as the difference between the large ebbflow and floodflow volumes that move back and forth between the delta region and San Francisco Bay. Discharges during peak periods of the ebb and flood tidal cycles may exceed 300,000 cubic feet per second. In consequence, a very high degree of precision must be maintained in the gross flow measurements if meaningful computations of net outflow are to be made. This report evaluates the probable accuracies that might be achieved by use of an AVM (acoustic velocity meter), a device which measures the stream velocity along a diagonal line across the channel. The study indicates that this line velocity will provide a stable index of the mean velocity in the channel and that such an index could be used as a primary parameter for the computation of discharge. Therefore, net outflows probably could be computed with the required accuracy by the use of such a device. The significant factors controlling the precision of measurement would be the stability of the channel geometry and streamline orientation, the precision with which the current-meter measurements needed for calibration of the system could be made, the instrumental calibration stability of the AVM system, and the length of period over which net outflows were computed. The AVM system developed by the U.S. Geological Survey in cooperation with the California Department of Water Resources and the U.S. Army Corps of Engineers does not have the required instrumental stability for this precise flow measurement. However, other AVM systems now being produced commercially seem to have the desired error characteristics, and a system probably can be procured that will permit computation of the fresh-water outflow from the delta area.

Water Supply Paper↗
USGS1970

Water resources of Racine and Kenosha Counties, southeastern Wisconsin

Urbanization and changes in regional development in Racine and Kenosha Counties are increasing the need for water-resources information useful for planning and management. The area is fortunate in having abundant supplies of generally good quality water available for present and projected future needs. Lake Michigan and ground-water reservoirs have great potential for increased development. Lake Michigan assures the urbanized area in the eastern part of the two counties of a nearly inexhaustible water supply. In 1967 the cities of Racine and Kenosha pumped an average of 32.6 mgd (million gallons per day) from the lake. Water from Lake Michigan is of the calcium magnesium bicarbonate type, but it is less hard than water from other sources. Discharge from Racine and Kenosha Counties into Lake Michigan is low and has little effect on the lake. The Root and Pike Rivers and a number of smaller streams contribute a mean flow of about 125 cfs (cubic feet per second) to the lake. Ground water, approximately 5 cfs, enters the lake as discharge from springs or as seeps. The Des Plaines, Root, and Pike Rivers drain areas of relatively impermeable silty clay that promotes rapid surface runoff and provides little sustained base flow. Sewage sometimes accounts for most of the base flow of the Root River. In contrast, the Fox River, which drains the western half of the area, has steady and dependable flow derived from the sand and gravel and the Niagara aquifers. Sewage-plant effluent released to the Fox River in 1964 was about 5 percent of the total flow. A 5-mile reach of the Root River loses about 30,000 gpd (gallons per day) per mile to the local ground-water reservoir and is a possible source of ground-water contamination. Thirty-five of the 43 lakes in the area are the visible parts of the groundwater table, and their stages fluctuate with changes in ground-water levels. The rest of the lakes are perched above the ground-water table. Flooding is a recurring but generally minor problem along occupied reaches of flood plains of all the streams. However, in 1960 a flood on the Fox River, which had a recurrence interval of 60 years, caused considerable damage near the village of Silver Lake. At the same time, a flood on the Root River, which had a recurrence interval of 100 years, caused damage in Racine. The sandstone aquifer, a major artesian reservoir underlying all of Racine and Kenosha Counties, is used as a water supply for industries, institutions, and three communities. Pumpage for these uses was about 3.3 mgd in 1967. The greatest decline of water levels, attributed to both local and regional pumping, was 7 feet per year at Burlington. The specific capacities of wells developed in the Mount Simon Sandstone are about 5 gpm (gallons per minute) per foot of drawdown; in the Galesville and Franconia Sandstones, about 4 gpm per foot of drawdown; and in the St. Peter Sandstone, about 1 gpm per foot of drawdown. Yields of more than 1,000 gpm are obtained from wells tapping the Galesville and Franconia Sandstones and penetrating large crevices in the Trempealeau Formation near Burlington and Union Grove. About 2.5 mgd of ground water in the sandstone aquifer was diverted from the two-county area toward the Milwaukee and Chicago pumping centers in 1963--about 1.7 mgd moving from Racine County toward Milwaukee and 0.8 mgd moving from Kenosha County toward Chicago. Recent regional waterlevel declines in the sandstone aquifer have ranged from about 3 to 5 feet per year. This decline in water levels represents a ground-water depletion of about 0.5 mgd; however, the aquifer is not being dewatered, nor are water levels declining in the recharge area. The sandstone aquifer receives about 80 percent of its recharge from its outcrop area west of the two counties. In 1963 about 3.5 mgd moved eastward laterally from the recharge zone in western Walworth County, and about 1 mgd leaked downward through the overly

Wisconsin↗
USGS1969

Water resources of Clark, Cleveland, and Dallas Counties, Arkansas

Clark, Cleveland, and Dallas counties constitute an area of 2,151 square miles in south-central Arkansas. The area is in two physiographic provinces--the Ouachita Mountains of the Ouachita province of the Interior Highlands, and the West Gulf Coastal Plain of the Coastal Plain province. The area is drained by the Ouachita, Saline, and Little Missouri Rivers and their tributaries. Although some of the streams in the project area can furnish dependable water supplies without storage, the amount of water available for use can be increased by the construction of reservoirs. The average surface-water yield in the area is about 1.4 cubic feet per second per square mile, or a total of about 3,000 cubic feet per second. Generally, the water quality is good; but water from some of the streams, particularly from the smaller tributaries, may require treatment for excessive iron content and high color. Ground-water yields in the project area vary considerably. The consolidated rocks in the Interior Highlands generally yield less than 10 gallons per minute to wells, precluding the development of large municipal or industrial groundwater supplies in that area. Of the 17 geologic units present in the Coastal Plain part of the project area, 12 yield water but in varying amounts. Among the formations of Cretaceous age, the Tokio yields good-quality water in the outcrop, but the quality deteriorates downdip; the Brownstown Marl yields small amounts of water for domestic purposes, mainly in the outcrop area ; the Ozan Formation yields a highly mineralized water that is generally unsuitable for most purposes; the Nacatoch Sand yields as much as 100 gallons per minute of good-quality water in and near the outcrop, but the water becomes very salty and corrosive at distances ranging from 2 miles downdip from the outcrop in northern Clark County to 17 miles downdip in the southern part of the county. The formations of Tertiary age offer the best possibilities for ground water, particularly in Dallas and Cleveland Counties. The Wilcox Group contains no thick widespread sands but contains thin sands locally. The quality of the water tends to deteriorate downdip, as the water becomes more mineralized and changes from a bicarbonate to a chloride type. The Carrizo Sand is undeveloped but may yield several gallons of water per minute per foot of drawdown in a large part of these two counties. High iron content may be a problem in water from the Carrizo. The Cane River Formation yields 50 gallons per minute of good-quality water to each of two wells at Sparkman. Elsewhere, high iron content of the water may be a problem. The Sparta Sand is the best aquifier in the project area, particularly east of central Dallas County. Well yields of 700 gallons per minute or more are possible. With minor treatment, the water is suitable for most purposes. The Cockfield Formation is utilized mainly for domestic supplies, but where the sands are thick, yields of as much as 300 gallons per minute are possible. The Jackson Group is utilized mainly for domestic supplies. In some areas, water from this unit contains such a high concentration of sulfate that it is unpalatable. The deposits of Quaternary age are thin and generally suitable only for domestic supplies. However, several wells that yield more than 200 gallons per minute have been developed in the alluvium south of Arkadelphia. Transmissibility values are highly variable, and test drilling is advisable to determine if large amounts of water are available at any specific site. Total water use in the project area in 1965 was about 6 million gallons per day, an increase of about 0.6 million gallons per day since 1960). Slightly more than one-half this amount was derived from surface-water sources. Total water use in the area in 1967 was insignificant compared with the total water available. DeGray Reservoir, now under construction on the Caddo River, will provide 250 million gallons per day for water

Water Supply Paper↗
USGS1969

Water resources of Randolph and Lawrence Counties, Arkansas

Water is used at an average rate of almost 27 million gallons per day in Randolph and Lawrence Counties, and quantities sufficient for any foreseeable use are available. Supplies for the large uses--municipal, industrial, and irrigation--can best be obtained from wells in .he Coastal Plain part of the counties and from streams in the Interior Highlands part. The counties have abundant supplies of hard but otherwise good-quality surface water, particularly in the Interior Highlands and along the western boundary of the Coastal Plain. Minimum recorded flows of four streams (Black, Current, Eleven Point, and Spring Rivers) exceeded 200 cubic feet per second, or 129 million gallons per day. Five other streams have flows in excess of 13 cubic feet per second 95 percent of the time. Water supplies can be obtained without storage from the larger streams in the area. Many of the smaller streams in the Interior Highlands also have large water-supply potential because of the excellent impoundment possibilities. Most of the water used in the .two counties is obtained from ground-water reservoirs in the Coastal Plain. Wells that tap alluvial deposits of Quaternary age commonly yield 1,000 gallons per minute. However, the water often is unsuitable for many uses unless treated to remove hardness, iron, and manganese. Water possibly may be obtained in the southeastern part of the area from the Wilcox Group of Tertiary age and the Nacatoch Sand of Cretaceous age, but these formations have not been explored in the report area. Wells in the Interior Highlands generally are less than 200 feet deep and yield 10 gallons per minute, or less. It may be possible to obtain greater amounts of ground water from two unexplored formations, the Roubidox and the Gunter Sandstone Member of the Van Buren Formation, in the Interior Highlands. Ground water in the Interior Highlands is very hard and is more susceptible to local bacterial contamination than is ground water in the Coastal Plain. However, with proper sanitary safeguards against contamination and with treatment for reduction of hardness, ground water in the Interior Highlands is suitable for most uses.

Water Supply Paper↗
USGS1969

Variations in low-water streambed elevations at selected stream-gaging stations in northwestern California

Graphs and a table are presented showing the variations in streambed elevations that have occurred over the years in the low-water channels at selected gaging stations in northwestern California. The streambed elevations are calculated from data obtained during discharge measurements. The greatest elevation changes that were recorded occurred between the 1964 and 1965 low-water periods. Those streambed changes are related to the flood of December 1964 and probably reflect large quantities of .sediment placed in the streams from bank erosion and landslides. At 25 of 51 stations with data for that period, elevation changes exceeded 1 foot, and at 42 stations the changes represented fill, rather than scour.

California↗