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Douglas K. Maurer

Publications and source records attributed to Douglas K. Maurer.

33 records · Page 2Linked to original sources
USGS1996

Hydrogeology and potential effects of changes in water use, Carson Desert agricultural area, Churchill County, Nevada

Operating Criteria and Procedures for Newlands Project irrigation and Public Law 101-618 could result in reductions in surface water used for agriculture in the Carson Desert, potentially affecting ground-water supplies from shallow, intermediate, and basalt aquifers. A near-surface zone could exist at the top of the shallow aquifer near the center and eastern parts of the basin where underlying clay beds inhibit vertical flow and could limit the effects of changes in water use. In the basalt aquifer, water levels have declined about 10 feet from pre-pumping levels, and chloride and arsenic concentrations have increased. Conceptual models of the basin suggest that changes in water use in the western part of the basin would probably affect recharge to the shallow, intermediate, and basalt aquifers. Lining canals and removing land from production could cause water-level declines greater than 10 feet in the shallow aquifer up to 2 miles from lined canals. Removing land from production could cause water levels to decline from 4 to 17 feet, depending on the distribution of specific yield in the basin and the amount of water presently applied to irrigated fields. Where wells pump from a near-surface zone of the shallow aquifer, water level declines might not greatly affect pumping wells where the thickness of the zone is greatest, but could cause wells to go dry where the zone is thin.

Water Supply Paper↗
USGS1994

Hydrogeology and potential effects of changes in water use, Carson Desert agricultural area, Churchill County, Nevada

Operating Criteria and Procedures established in 1988 for delivery of water for irrigation in the Newlands Project area include regulations and methods to increase Project efficiency. Public Law 101-618 of 1990 includes a target of 75-percent Project efficiency and a program of water-rights acquisition for wetlands maintenance. The directives could result in large reductions in water used for irrigation in the Carson Desert, potentially affecting ground-water supplies. Previous studies of the area have been evaluated to determine the current understanding of how aquifers are recharged, what controls the flow and quality of ground water, potential effects of changes in water use, and what additional information would be needed to quantify further changes in water use. Inflow of surface water to the basin from Lahontan Reservoir averaged about 370,000 acre-ft/yr (acre-feet per year) from 1975 to 1992, supplying water for irrigation of more than 50,000 acres. More than half of the water released from the reservoir is lost to seepage, operational spills, and evaporation before delivery of about 170,000 acre-ft/yr to farm headgates. The volume of water delivered to farms that does not contribute to crop consumptive use (on-farm loss) is poorly known but could be as much as 60,000 acre-ft/yr. Consumptive use on irrigated land may be about 180,000 acre-ft/yr, of which 50,000 acre-ft/yr may be derived from the shallow aquifer. Outflow from irrigated land is a mixture of operational spill, runoff from irrigated fields, and ground-water seepage to drains. Total outflow averages about 170,000 to 190,000 acre-ft/yr. This water flows to wetlands at Carson Lake, Stillwater Wildlife Management Area, and Carson Sink. Three sedimentary aquifers were previously defined in the basin: a shallow aquifer having highly variable lithology and water quality, an intermediate aquifer containing principally fresh water, and a deep aquifer having water of poor quality. The deep aquifer could possibly be divided into sedimentary and volcanic zones. In addition, a near-surface zone may exist near the top of the shallow aquifer where vertical flow is inhibited by underlying clay beds. A basalt aquifer near the center of the basin is the source of public supply and is recharged by the shallow, intermediate, and deep aquifers. Water levels in the basalt aquifer have declined about 10 feet from pre-pumping levels, and chloride and arsenic concentrations in the water have increased. The average depth to ground water has decreased beneath large areas of the Carson Desert since 1904 as a result of recharge of surface water used for irrigation. Ground water generally flows from west to east, and dissolvedsolids concentrations increase greatly near areas of ground-water discharge, where State of Nevada drinking-water standards commonly are exceeded. Uncertainties in the rates of recharge to and discharge from the basin cause an imbalance in the calculated water budget. Estimates for total recharge range from 400,000 to 420,000 acreft/yr, whereas estimates for discharge range from 630,000 to 680,000 acre-ft/yr. Estimates of inflow to and outflow from aquifers of the study area are as follows: shallow aquifer, more than 120,000 acre-ft/yr; intermediate aquifer, possibly more than 25,000 acre-ft/yr; deep aquifer, unknown; and basalt aquifer, about 4,000 acre-ft/yr. Estimates for flow volumes to and from the shallow and intermediate aquifers are based on assumed aquifer properties and could be in error by an order of magnitude or more. Conceptual models of the basin show that ground-water flow is downward from the shallow aquifer to the intermediate aquifer in the western part and near the center of the basin, and is upward in the eastern part of the basin. Little is known about flow in the deep aquifer. Nearsurface clay beds inhibit vertical flow near the center and eastern part of the basin except where breached by relict sand-filled channels of the Carson River. Conceptual models of the basin show that changes in water use in the western part of the basin probably would affect recharge to the sedimentary and basalt aquifers. Near the center of the basin, water-use changes could affect the shallow and basalt aquifers but might have less effect on the intermediate aquifer. In the eastern part of the basin, changes could affect the shallow aquifer, but would probably not affect the intermediate or basalt aquifers. If seepage is decreased by lining canals, and land is removed from production, water-level declines in the shallow aquifer could be greater than 10 feet as far as 2 miles from the lined canals. Depending upon the distribution of specific yield, decreasing recharge by 25,000 to 50,000 acre-ft/yr beneath 30,000 acres could cause water levels to decline from 4 to 17 feet. Where ground water supplements crop consumptive use, water levels could temporarily rise when land is removed from production. Where water is pumped from a near-surface zone of the shallow aquifer, water-level declines might not greatly affect pumped wells where the nearsurface zone is thickest, but could cause wells to go dry where the zone is thin. The understanding of surface-water and ground-water relations, recharge and discharge of ground water, ground-water movement, and the potential effects of changes in water use in the Carson Desert can be refined by studying (1) the extent of potable water in the intermediate and basalt aquifers, (2) lithology and specific yield of aquifer materials, (3) data on ground-water levels and quality, and (4) data on surface-water flow and quality, as well as monitoring the effects of changes in water use as they take place.

Nevada↗
USGS1994

Potential for, and possible effects of, artificial recharge in Carson Valley, Douglas County, Nevada

Rapid population growth in Carson Valley, west- central Nevada, requires a dependable municipal water source. Artificial recharge of aquifers using available flow of the Carson River is one way to increase the amount of water in underground storage and maintain a dependable ground-water supply. Ground water can be artificially recharged by routing excess surface water or, after proper treatment, routing wastewater to infiltration basins or injection wells. Withdrawal wells would remove stored water when needed. As a first step, maps showing areas in Carson Valley with high, low, moderate and unknown potential for artificial recharge were developed on the basis of the distribution of geologic units, depth to water, specific yield, infiltration rate, and location of natural recharge and discharge. For recharge by means of infiltration, areas totaling 5,700 acres have high potential, 23,900 acres have moderate potential, and 6,200 acres have low potential. For recharge through injection, areas totaling 7,800 acres have high potential and 43,500 acres have moderate potential; 23,000 acres have unknown potential because data are lacking on subsurface conditions. A ground-water-flow model was used to assess the possible results of artificial recharge. Simulations with no accompanying ground-water withdrawal show that, when recharge by injection is simulated near the valley floor, heads in the semiconfined aquifer increase over much of the valley, floor; only about 20 percent of the recharged water is stored in the aquifer after 5 years and as much as 80 percent is lost to streamflow and evapotranspiration. When recharge is simulated on the eastern side of the valley, 80 percent of the recharged water remains in storage after 5 years. When recharge is simulated near the valley floor, more water is lost to discharge than when recharge is on the eastern side of the valley. When recharge is applied for long periods without accompanying withdrawal, recharged water moves downgradient to discharge areas. The recharge water that discharges to the surface-water system could in turn replenish base flow of the Carson River and benefit downstream users.

Water-Resources Investigations Report↗
USGS1990

Ground-water resources of Honey Lake Valley, Lassen County, California, and Washoe County, Nevada

Honey Lake Valley is a 2,200 sq-mi, topographically closed basin about 35 miles northwest of Reno, Nevada. Unconsolidated basin-fill deposits on the valley floor and fractured volcanic rocks in northern and eastern uplands are the principal aquifers. In the study area, about 130,000 acre- ft of water recharges the aquifer system annually, about 40% by direct infiltration of precipitation and about 60% by infiltration of streamflow and irrigation water. Balancing this is an equal amount of groundwater discharge, of which about 65% evaporates from the water table or is transpired by phreatophytes, about 30 % is withdrawn from wells, and about 5% leaves the basin as subsurface outflow to the east. Results of a groundwater flow model of the eastern part of the basin, where withdrawals for public supply have been proposed, indicate that if 15,000 acre-ft of water were withdrawn annually, a new equilibrium would eventually be established by a reduction of about 60% in both evapotranspiration and subsurface outflow to the east. Hydrologic effects would be minimal at the western boundary of the flow-model area. Within the modeled area, the increased withdrawals cause an increase in the simulated net flow of groundwater eastward across the California-Nevada State line from about 670 acre-ft/yr to about 2,300 acre-ft/yr. (USGS)

California, Nevada↗
USGS1981

Geophysical reconnaissance of Lemmon Valley, Washoe County, Nevada

Rapid growth in the Lemmon Valley area, Nevada, during recent years has put increasing importance on knowledge of stored ground water for the valley. Data that would fill voids left by previous studies are depth to bedrock and depth to good-quality water beneath the two playas in the valley. Depths to bedrock calculated from a gravity survey in Lemmon Valley indicate that the western part of Lemmon Valley is considerably deeper than the eastern part. Maximum depth in the western part is about 2 ,600 feet below land surface. This depression approximately underlies the Silver Lake playa. A smaller, shallower depression with a maximum depth of about 1,500 feet below land surface exists about 2.5 miles north of the playa. The eastern area is considerably shallower. The maximum calculated depth to bedrock is about 1,000 feet below land surface, but the depth throughout most the eastern area is only about 400 feet below land surface. An electrical resistivity survey in Lemmon Valley consisting of 10 Schlumberger soundings was conducted around the playas. The maximum depth of poor-quality water (characterized by a resistivity less than 20 ohm-meters) differed considerably from place to place. Maximum depths of poor-quality water beneath the playa east of Stead varied from about 120 feet to almost 570 feet below land surface. At the Silver Lake playa, the maximum depths varied from about 40 feet in the west to 490 feet in the east. (USGS)

Open-File Report↗
USGS1978

Stamukhi shoals of the Arctic - some observations from the Beaufort Sea

A number of linear shoals, representing pronounced topographic anomalies on the surface of the Arctic shelf, have been studied in the Prudhoe Bay area. These shoals have been referred to in several previous studies. Based on seismic reflection records, Reimnitz et al., (1972a), stated that the shoals are constructional features younger than the post-Wisconsin transgression. Large chunks of grounded ice have frequently been seen on the linear shoals of the inner shelf. These ice chunks form barriers parallel to the shore (Reimnitz, et al. 1972b). Reimnitz and Barnes (1974) considered the lack of gravel concentrations on the shoals to be evidence that the stream of pack ice drifting past northern Alaska carries very little gravel today. Lewellen (1977) referred to the linear shoals as submerged barrier islands, while Reimnitz, et al., (1977b) pointed out that, although similar in shape to barrier islands, the linear shoals are very different in composition and do not appear to represent drowned harrier islands. They show that the shoals localize the formation of major shear and pressure events in the ice, which in turn cause the formation of linear belts of deformed and grounded ice. Today the shoals appear to be migrating under the influence of ice-bottom interaction, and indeed may have formed in response to ice-bottom interaction within the "stamukhi zone". The shoals migrate rather slowly and retain their shapes over periods of 25 years, yet control the location and stabilize the outer edge of the floating fast ice zone, and provide shelter for the inner shelf and coast. Reimnitz et al. (1977b) surmised that similar artificial structures might be used to modify the ice environment on the arctic shelf.

Alaska↗