Geology Reports⌕ Search

USGS · sir20075012

Bathymetry of Walker Lake, West-Central Nevada

Abstract

Walker Lake lies within a topographically closed basin in west-central Nevada and is the terminus of the Walker River. Much of the streamflow in the Walker River is diverted for irrigation, which has contributed to a decline in lake-surface altitude of about 150 feet and an increase in dissolved solids from 2,500 to 16,000 milligrams per liter in Walker Lake since 1882. The increase in salinity threatens the fresh-water ecosystem and survival of the Lahontan cutthroat trout, a species listed as threatened under the Endangered Species Act. Accurately determining the bathymetry and relations between lake-surface altitude, surface area, and storage volume are part of a study to improve the water budget for Walker Lake. This report describes the updated bathymetry of Walker Lake, a comparison of results from this study and a study by Rush in 1970, and an estimate of the 1882 lake-surface altitude. Bathymetry was measured using a single-beam echosounder coupled to a differentially-corrected global positioning system. Lake depth was subtracted from the lake-surface altitude to calculate the altitude of the lake bottom. A Lidar (light detection and ranging) survey and high resolution aerial imagery were used to create digital elevation models around Walker Lake. The altitude of the lake bottom and digital elevation models were merged together to create a single map showing land-surface altitude contours delineating areas that are currently or that were submerged by Walker Lake. Surface area and storage volume for lake-surface altitudes of 3,851.5-4,120 feet were calculated with 3-D surface-analysis software. Walker Lake is oval shaped with a north-south trending long axis. On June 28, 2005, the lake-surface altitude was 3,935.6 feet, maximum depth was 86.3 feet, and the surface area was 32,190 acres. The minimum altitude of the lake bottom from discrete point depths is 3,849.3 feet near the center of Walker Lake. The lake bottom is remarkably smooth except for mounds near the shore and river mouth that could be boulders, tree stumps, logs, or other submerged objects. The echosounder detected what appeared to be mounds in the deepest parts of Walker Lake, miles from the shore and river mouth. However, side-scan sonar and divers did not confirm the presence of mounds. Anomalies occur in two northwest trending groups in northern and southern Walker Lake. It is hypothesized that some anomalies indicate spring discharge along faults based on tufa-like rocks that were observed and the northwest trend parallel to and in proximity of mapped faults. Also, evaporation measured from Walker Lake is about 50 percent more than the previous estimate, indicating more water is flowing into the lake from sources other than the Walker River. Additional studies need to be done to determine what the anomalies are and whether they are related to the hydrology of Walker Lake. Most differences in surface area and storage volume between this study and a study by Rush in 1970 were less than 1 percent. The largest differences occur at lake-surface altitudes less than 3,916 feet. In general, relations between lake-surface altitude, surface area, and storage volume from Rush's study and this study are nearly identical throughout most of the range in lake-surface altitude. The lake-surface altitude in 1882 was estimated to be between 4,080 feet and 4,086 feet with a probable altitude of 4,082 feet. This estimate compares well with two previous estimates of 4,083 feet and 4,086 feet. Researchers believe the historic highstand of Walker Lake occurred in 1868 and estimated the highstand was between 4,089 feet and 4,108 feet. By 1882, Mason Valley was predominantly agricultural. The 7-26 feet decline in lake-surface altitude between 1868 and 1882 could partially be due to irrigation diversions during this time.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Thomas J. Lopes, J. LaRue Smith. 2007. Bathymetry of Walker Lake, West-Central Nevada. https://doi.org/10.3133/sir20075012

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

Slip tendency and dilation tendency of Quaternary faults in the Great Basin region, Arizona, California, Idaho, Nevada, Oregon, Utah, and Wyoming

This report presents the results of slip tendency and dilation tendency analysis of Quaternary faults in the Great Basin region, in the states of Arizona, California, Idaho, Nevada, Oregon, Utah, and Wyoming. This effort was undertaken as part of two studies: the U.S. Department of Energy Geothermal Technologies Office-funded Innovative Geothermal Exploration through Novel Investigations of Undiscovered Systems (INGENIOUS) project, which is a multidisciplinary, multi-institution effort to develop new methodologies and best practices to accelerate the discovery of new, commercially viable hydrothermal resources; and the U.S. Geological Survey Geothermal Resources Investigations Project. The goal of this work is to identify faults and fault segments that are appropriately oriented to be stress-loaded for slip or to dilate under the ambient stress conditions. Both conditions may make such faults more likely to host permeability and fluid flow relative to other faults in the region. Slip tendency and dilation tendency were calculated for all fault segments in the study area from the U.S. Geological Survey Quaternary Fault and Fold Database. Results demonstrate that faults with high slip tendency and dilation tendency are common in the Great Basin region. The areas containing many high slip tendency and dilation tendency fault segments are associated with high strain rates. These areas also host a relatively high proportion of the known hydrothermal systems. This indicates that faults with high slip tendency and dilation tendency in areas with high strain-rate are potentially most prospective for hosting hydrothermal systems. The database published in coordination with this report contains the slip tendency and dilation tendency results data, including the fault geometry and stress data used to calculate these quantities, for both the Great Basin study area and the smaller INGENIOUS study area.

Arizona, California, Idaho, Nevada, Oregon, Utah, ↗

A spatial analysis of the groundwater emergence flood hazard in Long Island, New York, and coastal areas surrounding Long Island Sound in New York, Connecticut, and Rhode Island

Long Island, New York, and nearby coastal areas surrounding Long Island Sound are densely populated and, like other coastal areas, are susceptible to flooding from several potential sources, including stormwater from precipitation events, tidal flooding and storm surge, and groundwater emergence flooding. Groundwater emergence fooding refers to the intersection of a rising water table with land surface or critical infrastructure. Many studies of flood drivers either neglect or only briefly discuss how shallow groundwater conditions may contribute to or exacerbate flood conditions. As a part of a comprehensive study of compound flood hazards in the coastal areas of Long Island and Long Island Sound, a spatial analysis was completed by the U.S. Geological Survey, in cooperation with the Environmental Protection Agency’s Long Island Sound Partnership, formerly called the Long Island Sound Study, using available regional datasets to characterize the potential hazard for groundwater emergence flooding. The approximately 3,100 square mile study area was subdivided into 11,407 grid cells that were 900 meters by 900 meters (approximately 3,000 feet by 3,000 feet), for the purpose of integrating the spatial datasets to calculate and map the groundwater emergence flood hazard. The depth to the water table, hydrologic soil groups, and National Land Cover Database were harmonized to the common grid. A groundwater emergence flood hazard score was calculated for each grid cell for current average conditions following a set of rules accounting for the depth to the water table and the percentage of area within each cell with slow infiltrating soils. A scenario with a higher sea-level position was also calculated for the Long Island part of the study area. The calculated groundwater emergence flood hazard score was reviewed in conjunction with the National Land Cover Database to identify developed areas and associated infrastructure that may be at risk of potential groundwater emergence flooding. Study results indicate that the groundwater emergence flood hazard is highest in coastal areas and near surface water where the water table is close to ground surface. Inland areas away from surface waterbodies are not likely to be exposed to groundwater emergence flooding. For Long Island, in the scenario with higher sea-level position, a greater groundwater emergence flood hazard is calculated for some locations closer to the coast and where land is submerged. Away from the coast and surface-water drainage, the groundwater emergence flood hazard is similar between the current average sea-level condition and the higher sea-level position scenario.

Connecticut, New York, Rhode Island↗

Streamflow assessment of Birch Creek, southern boundary of the Blackfeet Indian Reservation, Pondera County, northwestern Montana—Synoptic and continuous streamflow measurements through 2022

The U.S. Geological Survey, in cooperation with the Blackfeet Water Department, performed this study to assist water-resource managers in understanding and quantifying irrigation diversions, instream flows, and the spatial and temporal streamflow dynamics of Birch Creek in northwestern Montana. Birch Creek forms the southernmost boundary of the Blackfeet Indian Reservation and is highly valued culturally as an aquatic life and wildlife resource and as a principal source of water for irrigation. The study area included Birch Creek from Swift Dam to 53.3 miles downstream just above its confluence with the Two Medicine River. The study period was calendar year 2022, but selected historical information was also included in the study. Birch Creek streamflow originates through releases from Swift Reservoir, with the largest releases typically occurring during the irrigation season (May–October) to primarily meet the needs of downstream irrigators. This study included the compilation and collection of (1) continuous streamflow measured at streamgages installed for this study, (2) instantaneous streamflow measurements made during four synoptic events, and (3) reported daily values of Swift Reservoir outflow and irrigation diversions. Continuous streamflow data were available from two U.S. Geological Survey streamgages: Birch Creek below Heart Butte Road, near Heart Butte, Montana (upper streamgage; station 06094900), at river mile 12.9 and Birch Creek at Bullhead Bridge near Valier, Mont. (lower streamgage; station 06098120), at river mile 53.3. The upper streamgage (station 06094900) was primarily affected by the regulated releases from Swift Dam with daily mean streamflow typically slightly higher than the reported Swift Reservoir outflows. Daily mean streamflow ranged from 9.87 cubic feet per second (ft 3 /s) (November 18, 2022) to 640 ft 3 /s (June 22, 2022) during September 16, 2021–December 31, 2022. The mean annual streamflow was 122 ft 3 /s in water year 2022 (a water year is the 12-month period from October 1 to September 30 and is designated by the year in which it ends), about 13 percent greater than the mean annual reported Swift Reservoir outflows. The lower streamgage (station 06098120) was downstream from all major tributaries and diversions within the Birch Creek drainage basin. Daily mean streamflow ranged from 6.02 ft 3 /s (September 8, 2022) to 95.0 ft 3 /s (June 5, 2021) during August 26, 2020–December 31, 2022. Mean annual streamflow was 27.8 ft 3 /s for water year 2022. Flows at the lower streamgage (station 06098120) were typically lower than at the upper streamgage (station 06094900) from late April to early October, whereas flows from early October to late spring were similar to or greater than those at the upper streamgage. The upper streamgage had a total streamflow volume of 87,960 acre-feet (acre-ft) for water year 2022, whereas the lower streamgage had a total streamflow of 20,357 acre-ft. A net volume of about 67,603 acre-ft was removed from Birch Creek through diversions, losses to groundwater, and evapotranspiration along that reach during water year 2022. Most of the changes in main-stem streamflow could be accounted for by the tributary inflows or diversion outflows. The most dynamic streamflow gains and losses occurred along the upper few miles of Birch Creek. Streamflow was consistently lost to the groundwater system immediately below Swift Dam and then returned to levels that slightly exceeded the outflow at the dam near river mile 11.0. The overall net gains for the entire 53.3-mile study reach ranged from 15.5 to 42.6 ft 3 /s among the synoptic events. On several occasions, streamflow fell below minimum instream flow conditions specified in the Blackfeet Compact (water rights compact among the Blackfeet Tribe, State of Montana, and United States), which are subject to a 15-year deferral period (until June 12, 2033). Notably, a section of Birch Creek immediately downstream from Swift Dam was completely dry during the October 18, 2022, synoptic event.

Montana↗