Scientific Investigations Report 2006–5099
U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2006–5099
To quantify discharge from streams and springs within the park area, sites within eight drainage basins and one spring were selected for monitoring. Continual records of stream discharge were obtained from these sites using a stage-recording device. At other sites, streamflow data were obtained through a series of discrete discharge measurements.
Recording streamflow gages were installed near the park boundary to monitor stream discharge from selected drainage basins and one spring. These sites were on Strawberry Creek, which drains the northeast end of the park; Shingle Creek and Williams Canyon, which drain the western side of the park; Lehman, Baker, and Snake Creeks and Big Wash, which drain the eastern side of the park; Decathon Canyon, which drains the southern end of the park; and Rowland Spring, a tributary to Lehman Creek (fig. 1). Three additional streamflow gages were installed along Snake Creek to help characterize the variability of streamflow within selected areas of the Snake Creek drainage. The three additional sites selected for Snake Creek, in downstream order, were (1) above the pipeline diversion, (2) below the confluence with Spring Creek, and (3) at the Nevada–Utah State line (fig. 1). In all, 12 continual-recording streamflow gages were either installed or reactivated in the 8 stream drainages and 1 spring. Table 2 contains information on site location, altitude, drainage area, stream length and gradient, flow statistics, and period of record. Appendix A (at back of report) includes photographs of each gage site.
Data were collected at all but two sites during a 2-year period from October 2002 to September 2004 (water years 2003 and 2004). Water year 2003 is defined as beginning on October 1, 2002, and ending on September 30, 2003. Each streamflow gage was visited periodically for routine maintenance of stage-recording equipment and measurements of stream discharge using a current meter in accordance with standard USGS techniques (Rantz and others, 1982a, 1982b). Streamflow rates were determined using flumes and volumetric methods at selected sites during periods of low flow. Stage-discharge relations were developed for each gage and used to compute daily mean discharges. Additionally, continual water-temperature data were collected at each site, and daily mean temperatures were computed. Hydrographs and tables of daily mean discharge and continual water-temperature for water years 2003 and 2004 for each gage are included in appendix B (at back of report).
Strawberry Creek is a principal drainage basin at the northeast end of the park, with an areal extent of 9.45 mi2 (fig. 1). The creek is perennial, flows to the northeast, and is tributary to Weaver Creek, which flows into Snake Valley. Altitudes within the drainage range from 11,562 ft at the summit of Bald Mountain to 6,020 ft at the confluence with Weaver Creek (fig. 1).
The Strawberry Creek gage was established on October 8, 2002, and was about 600 ft upstream of the park boundary (fig. 3; appendix A, photographs A1). No impoundments or diversions were observed upstream of the gage. Downstream of the gage, at an altitude of 6,180 ft, water is diverted through a pipeline to irrigate fields along Weaver Creek.
Shingle Creek is one of many small perennial streams that drain the steep, northwest slopes of the southern Snake Range (fig. 1). The Shingle Creek drainage encompasses an area of 2.22 mi2 originating at an altitude of 11,780 ft near the summit of Wheeler Peak. The creek flows southwest and becomes poorly defined when it reaches the alluvial slope at an altitude of about 6,950 ft. At 6,550 ft, downstream of synoptic measurement site Sh4 (fig. 4), flow is diverted through a 2.2-mile long pipeline for irrigation in Spring Valley.
The Shingle Creek gage was established on September 5, 2002, about 0.25 mi downstream of the park boundary (fig. 4; appendix A, photographs A2). No impoundments or diversions were observed upstream of the gage.
Lehman Creek drains the northeastern slopes of the southern Snake Range and is the third largest stream in the park (fig. 1). The entire drainage area encompasses 15.6 mi2, and ranges in altitude from 13,063 ft at Wheeler Peak to about 5,260 ft just upstream of the Baker Reservoir in Snake Valley. Headwaters of Lehman Creek flow from glacial cirques on the north side of Wheeler Peak and from the south side of Bald Mountain (fig. 1). The stream is perennial and generally flows eastward from the range crest at about 10,000 ft down to Snake Valley. Downstream of the park boundary, tributary inflow enters Lehman Creek from Rowland Spring and Baker Creek. Downstream of the confluence with Rowland Spring, higher flows from snowmelt runoff disperse into several irrigation ditches, but coalesce back into a single channel upstream of the confluence with Baker Creek. Streamflow from Baker Creek merges into Lehman Creek about 2 mi downstream of the park boundary by means of a diversion ditch that was dug in 1916 (Frantz, 1953). Downstream of the confluence, the combined flow of Lehman and Baker Creeks enters a large pond where all but the highest flows are diverted into a 1.6‑mile long concrete-lined irrigation channel (fig. 5).
Lehman Creek previously had been gaged by the USGS from December 1947 to September 1955, and from October 1992 to September 1997. The former gage, about 0.5 mi upstream of the park boundary, was reactivated on July 17, 2002 (appendix A, photographs A3).
Rowland Spring is the second largest spring in the southern Snake Range (Gretchen Baker, National Park Service, Great Basin National Park, oral commun., 2005) and is tributary to Lehman Creek (fig. 1). The shallow spring pool is about 30 ft in diameter by about 1 ft deep and drains to the east (appendix A, photographs A4). Discharge from the spring splits into two channels about 20 ft downstream of the spring pool. The northern fork merges into Lehman Creek about 100 ft downstream of the spring pool, whereas the southern fork flows south of and parallel to Lehman Creek for about 0.75 mi before merging with Lehman Creek. Flow in the southern fork is diverted for irrigation during periods of spring runoff. The Rowland Spring gage was established on September 4, 2002, at the spring pool about 25 ft upstream of the park boundary (fig. 5).
Baker Creek is the second largest creek in the park and drains the northeastern edge of the southern Snake Range (fig. 1). The entire drainage encompasses an area of 24.3 mi2 that ranges in altitude from 13,063 ft along the southern summit of Wheeler Peak to about 5,190 ft in Snake Valley. Headwaters of Baker Creek originate from three subdrainages: North Fork Baker Creek, Baker Creek, and South Fork Baker Creek. North Fork Baker Creek drains the southeast slope of Wheeler Peak, whereas Baker and South Fork Baker Creeks drain the eastern and northeastern slopes of Baker Peak and Pyramid Peak, respectively. Baker Lake, the largest alpine lake in volume within the southern Snake Range (Gretchen Baker, National Park Service, Great Basin National Park, oral commun., 2005), provides flow to Baker Creek during periods of snowmelt. Downstream of the confluence of the three drainages, Baker Creek is perennial and drains to the northeast before terminating in Lehman Creek, about 2 mi downstream of the park boundary.
Baker Creek was gaged by the USGS from December 1947 to September 1955, and from October 1992 to September 1997. The former gage, about 25 ft upstream of the park boundary, was reactivated on October 8, 2002 (fig. 5; appendix A, photographs A5).
Headwaters of Snake Creek originate on the south side of Pyramid Peak and the north side of Mount Washington (fig. 1). The creek flows east across the central part of the southern Snake Range and into Snake Valley where it is used for irrigation. The Snake Creek drainage area encompasses 38.4 mi2, ranges in altitude from 11,926 ft at Pyramid Peak to about 5,230 ft in Snake Valley, and is the largest drainage area within the park (fig. 1). Flow is perennial within the upper and lower reaches of the creek and is intermittent for most of the central part of the drainage. One prominent, intermittent reach starts at an altitude of about 7,600 ft, and extends downstream about 3 mi. In 1961, local ranchers constructed a pipeline that conveys baseflow over the entire 3 mi of this stream channel. At the end of the pipeline, perennial springflow discharging into the channel combines with the diverted flow. At the park boundary, about 2.2 mi downstream of the end of the pipeline, flow becomes intermittent during winter months. Near the lower end of the drainage area, streamflow is perennial below an altitude of about 6,000 ft because of ground-water discharge to Snake Creek and tributary flow from Spring Creek.
The uppermost gage of the four gages on Snake Creek was installed on September 5, 2002. The gage is about 2 mi upstream of the park boundary and about 100 ft upstream of the pipeline diversion (fig. 6; appendix A, photographs A6). No impoundments or diversions were observed upstream of the gage.
The streamflow gage Snake Creek at Great Basin National Park boundary was installed on September 6, 2002. The gage was at the park boundary about 2.2 mi downstream of the end of the pipeline (fig. 6;appendix A, photographs A7). Flow at the gage is intermittent.
The gage on Snake Creek below Spring Creek was installed on January 8, 2003. The gage was about 1.7 mi downstream of the park boundary and about 0.1 mi downstream of the confluence of Spring Creek with Snake Creek (fig. 6; appendix A, photographs A8). Snake Creek at the gage is perennial. The State of Nevada operates the Spring Creek Rearing Station, which diverts flow from Spring Creek and Snake Creek upstream of the gage. Operations at the rearing station resulted in numerous, abrupt changes in streamflow at the gage, which occurred when operators cleaned or filled the large fish tanks.
The gage on Snake Creek at the Nevada–Utah State line was installed on January 8, 2003, and was about 40 ft upstream of the State line (fig. 6; appendix A, photographs A9). The stream is perennial. Regulation of flow in Spring and Snake Creeks during operations at the Spring Creek Rearing Station affected streamflow at this gage.
Big Wash begins on the southeast side of the southern Snake Range (fig. 1). The highest altitude in the Big Wash drainage exceeds 11,000 ft (fig. 6). South Fork Big Wash generally flows east and joins North Fork Big Wash just outside of the park boundary. Both forks are intermittent at their confluence and, except for areas where ground-water discharges to Big Wash, the channel is intermittent for much of its length. Big Wash continues east to Snake Valley where it intersects Pruess Lake (fig. 1). The Big Wash drainage encompasses an area of 28.8 mi2 that ranges in altitude from 11,658 to 5,360 ft. Streamflow is diverted within the drainage area to fill fish-rearing ponds, irrigate fields for grazing, and supply living quarters and recreational facilities for a large ranch-style resort in the lower part of the drainage.
The South Fork Big Wash gage was installed on October 9, 2002, about 150 ft upstream of the park boundary (fig. 6; appendix A, photographs A10). A perennial spring is about 0.5 mi upstream of the gage; however, spring flow infiltrates the streambed about 100 ft upstream of the gage during winter months. No impoundments or diversions were observed upstream of the gage.
Williams Canyon is a small, steep drainage basin that drains the west-central slopes of the southern Snake Range (fig. 1). The drainage originates along the ridge between Baker and Pyramid Peaks and perennially drains to the southwest. Similar to Shingle Creek, the channel for Williams Canyon becomes poorly defined when it reaches the alluvial slope. The Williams Canyon drainage encompasses an area of 3.33 mi2 that ranges in altitude from about 11,775 to 7,200 ft near the fan apex. About 1.5 mi downstream of the park boundary, at an altitude of 7,250 ft, water is diverted into a pipeline and used to irrigate fields in Spring Valley. The Williams Canyon gage was installed on October 11, 2002, about 1.4 mi downstream of the park boundary (fig. 7; appendix A, photographs A11). No impoundments or diversions were observed upstream of the gage.
Decathon Canyon is tributary to Big Spring Wash, which drains the southern end of the southern Snake Range (fig. 1). The Decathon Canyon drainage originates along the western slopes of Granite Peak, and encompasses an area of 11.7 mi2. The drainage area ranges in altitude from 11,532 to 7,300 ft at the confluence with Big Spring Wash. Decathon Canyon drains to the south within the park, but flows to the southeast downstream of the park boundary. Streamflow in Decathon Canyon is intermittent and typically occurs during periods of intense summer thunderstorms.
The Decathon Canyon gage was installed on October 10, 2002, about 0.1 mi downstream of the park boundary (fig. 8; appendix A, photographs A12). The gage was the highest of the 12 monitoring sites at an altitude of 8,410 ft (fig. 1). No diversions were observed upstream of the gage; however, several small springs within the drainage area have been developed as watering holes for wildlife. For water years 2003 and 2004, the mean annual discharge was 0 ft3/s (table 2). Flow only occurred on June 24, 2003, and on September 3, 2004. Daily mean discharge for both days was 0.1 ft3/s.
Streamflow within each drainage basin can vary greatly because of the distribution of permeable and impermeable rocks within the basin. Gains in streamflow generally occur from tributary and spring inflows, or from ground-water discharge into the channels, whereas losses in streamflow occur from evapotranspiration (ET) or infiltration. To quantify gains and losses in streamflow, seepage runs typically are done along selected reaches of a stream. A seepage run is a set of instantaneous discharge measurements made at selected intervals along a stream channel within a short period of time, usually less than 2 days. Seepage data previously collected by the USGS for Great Basin National Park (Hess and others, 1992) were compiled, and new seepage runs were performed on selected streams for this study.
In 1992, seepage runs were made by the USGS on Lehman, Baker, and Snake Creeks (Hess and others, 1992). Data collected during these seepage runs included instantaneous discharge measurements of streamflow, specific conductance, and water temperature (table 3). Measurements were made upstream and downstream of tributaries, and at randomly picked intervals within the channel. These seepage runs started at the upper elevations of each drainage, and consisted of one streamflow measurement at each site before descending the stream channel to the next site. On September 1–2, 1992, 23 instantaneous measurements were made along Lehman Creek, starting upstream of the Wheeler Peak Campground (fig. 5) and ending at State Highway 487 in Baker, Nev. (fig. 1). During this same period, 17 instantaneous measurements were made along Baker Creek, beginning upstream of the confluence with Timber Creek and ending at the confluence with Lehman Creek (fig. 5). On September 3, 1992, 23 instantaneous measurements were made along Snake Creek. Measurements started downstream of the Shoshone Campground and ended just upstream of the Nevada–Utah State line (fig. 6).
The main purpose of the seepage runs in the current study was to assess the spatial and temporal variability of flow rates within the context of local-channel geology. Seepage runs were made in June, July, and October 2003 within selected reaches of Strawberry, Shingle, Lehman, Baker, and Snake Creeks and Big Wash. Fewer sites were needed for this study than in 1992 because measurement sites were constrained by geologic changes. As a result, six sites were selected for Strawberry Creek (fig. 3), four sites for Shingle Creek (fig. 4), seven sites each for Lehman and Baker Creeks (fig. 5), eight sites for Snake Creek, and six sites for Big Wash (fig. 6). Streamflow measurements made in 2003 were done synoptically; that is, measurements were made at the same time of day for all sites along a selected stream. A minimum of three measurements were made at each site, and were averaged to increase confidence in the values used in this study.
Current meters, flumes, and volumetric methods were used to measure streamflow during the 2003 seepage runs. The accuracy of these measurements varied from good to poor, which means the measurement error ranged from 5 to greater than 8 percent, respectively, of the actual discharge (table 4; Sauer and Meyer, 1992). Measurements of specific conductance and water temperature were collected at each site by NPS staff using a YSI 85 System multimeasurement meter. The accuracy of the meter is ±0.5 percent full scale for specific conductance, and ±0.1°C (±1 least significant digit) for water temperature (http://www.ysi.com/environmental.htm). Stream discharge and water-property data collected during the synoptic measurements are included in table 4. Measurement errors for specific conductance were based on criteria described in the USGS National Field Manual for the Collection of Water-Quality Data (Radtke and others, 2005).
Water samples were collected for quality control by the USGS and analyzed in the Nevada Water Science Center laboratory to check the specific conductance field measurements. Differences in specific conductance between the Nevada Water Science Center laboratory and field measurements were within measurement error with the exception of two sites, one in Snake Creek and one in South Fork Big Wash. Laboratory values were substituted for the field measurements in table 4 for these two sites. Water and air temperatures also were measured by each field crew, using standard alcohol field thermometers, at the beginning, midpoint, and end of the streamflow measurements at each site. Mean values were computed for each set of water- and air-temperature readings (table 4).
ET either directly from the stream or from riparian vegetation adjacent to the stream was considered in this study because it may cause streamflow to decrease downstream, particularly during the summer months. ET directly from a stream could result in a gradual loss of flow downstream and, if ET is sufficiently large, it likely would increase the specific conductance of the stream. ET from riparian vegetation adjacent to the stream could increase infiltration rates along the stream but would not increase the specific conductance of the stream, because the concentration of salts from ET would occur in the water in the alluvium beneath the riparian vegetation.
ET either directly from the stream or from the riparian vegetation adjacent to the stream was not measured during the synoptic seepage runs. However, ET data were compiled from studies that included such measurements and found that the quantity of water lost as a result of ET was minimal compared to streamflow (Constantz and others, 1994; Ronan and others, 1998). In May 1994, the ET rate estimated in Vicee Canyon near Carson City, Nev. (see inset map in fig. 1 for location of Carson City), was 2×10-7 ft/s, and included the adjacent riparian area (Ronan and others, 1998). Hourly measurements of evaporation from Cold Creek, a tributary stream to Lake Tahoe about 35 mi southwest of Carson City, were taken on June 16 and September 24, 2004, using a hemispherical dome. Measurements at Cold Creek indicated a maximum ET rate during the day of 1×10-7 ft/s for June 16, and 6×10-8 ft/s for September 24 (Michael Johnson and Jena Green, U.S. Geological Survey, written commun., 2005). The altitude of the measurement site at Cold Creek was about 6,270 ft. Because Cold Creek is at a similar altitude and latitude as many of the streams in Great Basin National Park, the maximum daily ET rate from Cold Creek was applied to streams in this study. The ET rate was multiplied by a standard area for each stream, based on the average width of the stream measured during the synoptic seepage runs in June, July, and October 2003, and a stream length of 1 mi. The computed maximum ET rate for the streams in Great Basin National Park in June and July 2003 ranged from 0.002 (ft3/s)/mi for Strawberry and Shingle Creeks to 0.005 (ft3/s)/mi for Lehman and Snake Creeks. The maximum ET rate in October, assuming the maximum ET rate was the same as that measured for Cold Creek in September 2004, ranged from 0.001 (ft3/s)/mi for Strawberry, Shingle, and Snake Creeks, and Big Wash to 0.003 (ft3/s)/mi for Lehman Creek. This indicates that evaporation from the stream channel has little to no effect on streamflow and consequently on specific conductance of the streams.
Many streams begin within the park boundary and discharge into the adjacent valleys (fig. 1). Streams are perennial in the northern half of the park where altitudes are higher, precipitation is greater, and the older undifferentiated rocks and intrusive rocks only store and transmit small quantities of water. Streamflow commonly increases near the mountain front because ground water is near land surface and potential recharge to ground water is rejected (fig. 9; Theis, 1940). Farther downstream on the alluvial slope, the water table is well below land surface and the streams lose water as they supply recharge to ground water. Stream losses and depth to ground water increase where faulting abruptly increases the thickness of alluvial deposits (Ronan and others, 1998). Many of the perennial streams discharging from the southern Snake Range are diverted on the alluvial slopes for irrigation in Spring and Snake Valleys.
Streams are intermittent in the southern half of the park because altitudes are lower, precipitation is less, and the underlying rocks consist of thick sections of permeable carbonate rocks. Most precipitation not lost to ET percolates into the rocks and becomes ground water. The water table in this region is well below the stream channels, and small springs that occur within the park locally are perched above the regional water table. Larger springs discharge near or at the base of the alluvial slopes along the southeast and southwest sides of the southern Snake Range.
Selected climate data available for the study period were compiled from the NWS weather station at the Lehman Caves Visitor Center, Great Basin National Park, to evaluate the effects of climate on streamflow. These data were compared to long-term averages for 1971–2000 published by the National Oceanic and Atmospheric Administration (2002). Annual mean air temperatures for water years 2003 and 2004 were 1.0ºC and 0.4ºC greater than the 30-year average, respectively (fig. 10). Precipitation totals for water years 2003 and 2004 were close to the 30-year average (fig. 11).
The Natural Resources Conservation Service measures snowpack at three sites in Great Basin National Park (fig. 5). These sites are along Baker Creek and range in altitude from 8,220 ft at Baker Creek #1 (BCs1); 9,220 ft at Baker Creek #2 (BCs2); and 9,520 ft at Baker Creek #3 (BCs3; Natural Resources Conservation Service, 2005). Annual snowpack is based on depth of snow measurements made at the beginning of April of each year, because snowpack depth usually peaks around April 1 (Ray Wilson, Natural Resources Conservation Service, oral commun., 2005). The mean annual snowpack for 1971–2000, based on snow-water equivalent, was 5.8 in. at BCs1, 14.1 in. at BCs2, and 17.1 in. at BCs3 (fig. 12; Natural Resources Conservation Service, 2005). Snowpack totals for these three sites in 2003 and 2004 ranged from about 25 to 80 percent of normal (Ray Wilson, Natural Resources Conservation Service, written commun., 2005; Natural Resources Conservation Service, 2005).
Lehman and Baker Creeks had the only gages with adequate records for developing long-term mean annual discharges. Although there are large gaps in the record, 15 years of data were available for both gages from December 1947 to September 1955, October 1992 to September 1997, and October 2002 to September 2004 (fig. 13). Mean annual discharges for Lehman and Baker Creeks are 5.13 and 9.08 ft3/s, respectively. Annual mean discharges for Lehman Creek for water years 2003 and 2004 were 4.02 and 3.47 ft3/s, respectively, and are 78 and 68 percent of the mean annual discharge. Annual mean discharges for Baker Creek for water years 2003 and 2004 were 6.22 and 4.90 ft3/s, respectively, and are 69 and 54 percent of the mean annual discharge. With the exception of the two lower Snake Creek streamflow gages, all other continual-recording gages in the current study (table 2) had at least 2 years of data. Mean annual discharges were computed for these gages, and ranged from 0 ft3/s at Decathon Canyon to 2.70 ft3/s at Snake Creek above pipeline (table 2). Annual mean discharges were not computed for the two lower Snake Creek gages because they had only 21 months of record.
Minimum and maximum mean monthly discharges occurred in February and June, respectively, at Lehman and Baker Creeks for the 15 years of record (1948–55, 1993–97, 2003–04; fig. 14) and at most other perennial streamflow gages, including Rowland Spring. Maximum mean monthly discharges occurred in June for the intermittent gages, Snake Creek at park boundary and South Fork Big Wash. Mean monthly discharges could not be computed for Decathon Canyon, as the drainage was dry most of the year.
Mean annual discharge decreased from water year 2003 to 2004 by an average of 22 percent for perennial streams with two or more complete years of record (Strawberry, Shingle, Lehman, and Baker Creeks; Snake Creek above pipeline; and Williams Canyon). The decrease ranged from 14 percent at Lehman Creek to 36 percent at Strawberry Creek. Mean annual discharges for the two intermittent streams with 2 years of record, Snake Creek at park boundary and South Fork Big Wash, decreased by 24 and 48 percent, respectively. Mean annual discharge for Rowland Spring decreased 6 percent.
Relating streamflow records to precipitation and snowpack data for the park indicates that annual streamflow rates may be more dependent on the volume of snow in the lower altitudes than total precipitation. Although the annual means for Lehman and Baker Creeks for water years 2003 and 2004 are significantly less than their respective mean annual discharges, the 2003 and 2004 annual means are not the lowest of record, nor do the plots for the period of record show any discernible trends. Annual mean discharges were lower at both gages in 1953 (fig. 13).
The relation between the annual mean discharge of Lehman and Baker Creeks has not changed over the period of record (fig. 15A). The annual mean discharges for both gages were compared to Lamoille Creek on the northeast side of the Ruby Mountains near Elko, Nev. (see fig. 1 inset map; USGS station 10316500, Lamoille Creek near Lamoille, Nev.; streamflow data can be accessed online at http://waterdata.usgs.gov/nv/nwis). Lamoille Creek was chosen because (1) it is the nearest stream gage that has annual mean discharges for the same years as Baker and Lehman Creeks, (2) it has a drainage area of 24.9 mi2, and (3) streamflow of Lamoille Creek upstream of the gage is not affected by diversions or use. Although climate variations affect the relation of annual mean discharge of Lamoille Creek with respect to Baker and Lehman Creeks (fig. 15B), the overall trend indicates no long-term change in the relation. The comparisons shown in figure 15 could be used to determine any future effects on the annual mean discharges of Baker and Lehman Creeks caused by increased ground-water withdrawals in Snake Valley, assuming streamflow in Lamoille Creek remains natural. Although Lamoille Creek is distant from Great Basin National Park (fig. 1), it may serve as a comparative control because it will not be affected by proposed ground-water withdrawals in eastern Nevada.
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