Prepared in cooperation with the Uintah Water Conservancy District and the Bureau of Reclamation

Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

Scientific Investigations Report 2019–5101

U.S. Department of the Interior U.S. Geological Survey Cover: View of Red Fleet Reservoir looking northeast near well DH-109; photograph taken by Mike Hess, U.S. Geological Survey, August 2016. Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

By Thomas M. Marston, John E. Solder, and Katherine K. Jones

Prepared in cooperation with the Uintah Water Conservancy District and the Bureau of Reclamation

Scientific Investigations Report 2019–5101

U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DAVID BERNHARDT, Secretary U.S. Geological Survey James F. Reilly II, Director

U.S. Geological Survey, Reston, Virginia: 2019

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Suggested citation: Marston, T.M., Solder, J.E., and Jones, K.K., 2019, Groundwater and surface-water resources near Red Fleet Reservoir, Uintah County, Utah: U.S. Geological Survey Scientific Investigations Report 2019–5101, 40 p., https://doi.org/10.3133/sir20195101.

ISSN 2328-0328 (online) iii

Contents

Abstract...... 1 Introduction...... 1 Hydrogeology...... 3 Assessment of Groundwater Interaction with Red Fleet Reservoir...... 3 Data Collection Methods and Results...... 3 Surface-Water Inflow to and Outflow from Red Fleet Reservoir...... 3 Pumped Outflow from Red Fleet Reservoir...... 5 Meteorological Data...... 22 Water-Level Data...... 23 Groundwater Movement...... 24 Estimates of Groundwater Recharge and Discharge from Red Fleet Reservoir...... 25 Changes in Reservoir Storage...... 25 Reservoir Evaporation...... 25 Estimates of Groundwater Recharge and Discharge at Red Fleet Reservoir...... 26 Big Brush Creek Seepage Assessment Upstream of Red Fleet Reservoir...... 27 Evaluation of Aquifer Properties in the Nugget Sandstone Aquifer near Red Fleet Reservoir...... 28 Aquifer Test Description and Analysis...... 28 Evaluation of Groundwater Geochemical Characteristics in the Nugget and Frontier Sandstones...... 32 Data Collection Methods...... 32 Data Interpretation Methods...... 32 Noble Gases...... 32 Tritium and Helium Isotopes...... 33 Lumped Parameter Modeling...... 34 Categorical Tritium Age...... 34 Groundwater Age...... 34 Water-Quality Results...... 34 Major Ions, Nutrients, and Trace Metals...... 34 Environmental Tracer Results...... 36 Noble-Gas Analysis...... 36 Age Tracers and Mean Age...... 37 Discussion...... 38 Summary...... 38 References Cited...... 39 iv

Figures

1. Image showing location of the Red Fleet Reservoir study area, Uintah County, Utah...... 2 2. Map showing gocation of wells, streamgage, and pump station near Red Fleet Reservoir, Utah...... 4 3. Graph showing annual inflows and outflows to and from Red Fleet Reservoir, near Vernal, Utah, 1980–2015...... 5 4. Graph showing annual precipitation at Vernal Airport and Natural Resources Conservation Service Split Mountain weather stations, Utah, 1980–2015...... 22 5. Graph showing water-level altitude in selected wells and Red Fleet Reservoir stage, Uintah County, Utah, 2016–17...... 23 6. Image showing potentiometric contours of the Nugget and Frontier Sandstone aquifers in September 2017, Red Fleet Reservoir, Utah...... 24 7. Graph showing reservoir stage and calculated groundwater recharge/discharge at Red Fleet Reservoir, Utah, 1980–2015...... 26 8. Image showing locations of seepage measurements taken on November 17, 2017, on Big Brush Creek upstream of Red Fleet Reservoir, Utah...... 27 9. Graph showing measured discharge and uncertainty at two stations on Big Brush Creek upstream of Red Fleet Reservoir, Utah...... 28 10. Graph showing recorded discharge at the U.S. Geological Survey Big Brush Creek streamgage 09261700 during the November 17, 2017, seepage assessment above Red Fleet Reservoir, Utah...... 28 11. Image showing locations of wells and discharge pipe used during the March 2017 Nugget Sandstone aquifer test at Red Fleet Reservoir, Utah...... 29 12. Graph showing measured change in water level from observation well RF1 near Red Fleet Reservoir resulting from pumping at the Red Fleet State Park well, and simulated change in water level from a Theis aquifer-response solution, March 2017, Red Fleet Reservoir, Utah...... 30 13. Trilinear diagram showing relative major-ion concentrations for selected wells near Red Fleet Reservoir, Utah...... 31 14. Graph showing modeled noble-gas recharge temperature and elevation for groundwater sampled near Red Fleet Reservoir, Utah...... 36 15. Graph showing age-tracer cross-plot of groundwater near Red Fleet Reservoir, Utah...... 37

Tables

1. Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015...... 6 2. Field measurements and major ions, selected trace elements, and nutrient concentrations in groundwater and surface water from selected sites near Red Fleet Reservoir, Utah...... 35 3. Noble-gas model results from samples collected at Red Fleet Reservoir, Utah...... 36 4. Age-tracer concentrations and estimated mean age and age distribution of groundwater near Red Fleet Reservoir, Utah...... 37 v

Conversion Factors

U.S. customary units to International System of Units

Multiply By To obtain Length inch (in.) 2.54 centimeter (cm) foot (ft) 0.3048 meter (m) mile (mi) 1.609 kilometer (km) Area acre 4,047 square meter (m2) acre 0.004047 square kilometer (km2) square foot (ft2) 929.0 square centimeter (cm2) square inch (in2) 6.452 square centimeter (cm2) Volume gallon (gal) 3.785 liter (L) cubic foot (ft3) 0.02832 cubic meter (m3) acre-foot (acre-ft) 1,233 cubic meter (m3) Flow rate gallon per minute (gal/min) 0.06309 liter per second (L/s) Hydraulic conductivity foot per day (ft/d) 0.3048 meter per day (m/d)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: °F = (1.8 × °C) + 32. Datums

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88). Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83). Altitude, as used in this report, refers to distance above the vertical datum.

Supplemental Information

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25 °C). Total dissolved gas pressure is reported in millimeters of mercury (mm Hg), where 760 mm Hg equals one atmosphere. Concentrations of chemical constituents in water are given in either milligrams per liter (mg/L) or micrograms per liter (µg/L). Stable isotope concentration is reported as per mil, which is equivalent to parts per thousand. Tritium units (TU) are used to report tritium concentration, where one TU equals tritium concentration in picoCuries per liter divided by 3.22. vi

Chlorofluorocarbon concentrations are reported as picomoles per kilogram (pmol/kg). Sulfur hexafluoride concentrations are reported as femtomoles per kilogram (fmol/kg).

Abbreviations

3H tritium 3He helium-3

3 Hetrit tritiogenic helium-3 4He helium-4

4 Heterr terrigenic helium-4 AVWTP Ashley Valley Water Treatment Plant CE closed-system equilibration CFC-11 trichlorofluoromethane CFC-113 1,1,2-trichloro-1,2,2-trifluoroethane CFC-12 dichlorodifluoromethane CFC chlorofluorocarbon DM dispersion model EPA Environmental Protection Agency He helium

Heterr terrigenic helium Kr krypton LPM lumped parameter modeling ml milliliter NGT noble-gas recharge temperature NRCS Natural Resources Conservation Service PET potential evaporation RFSP Red Fleet State Park SCAN Soil Climate Analysis Network

SF6 sulfur hexafluoride TDG total dissolved gas BOR Bureau of Reclamation USGS U.S. Geological Survey UWCD Uintah Water Conservancy District Xe xenon σ standard deviation χ2 chi-squared statistic Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

By Thomas M. Marston, John E. Solder, and Katherine K. Jones

Abstract and no trace elements above the Environmental Protection Agency drinking-water standards. Water sampled from the Red Fleet Reservoir in Uintah County, Utah, is an Frontier Sandstone aquifer yielded poor-quality water with approximately 26,000 acre-foot (acre-ft) on-channel reservoir dissolved-solids concentrations of about 2,150 milligrams per in the Big Brush Creek drainage on the south slope of the liter and arsenic approaching the drinking-water standard of Uinta Mountains. It is operated primarily for irrigation needs 10 milligrams per liter. Dissolved noble gases used to identify while providing a supplemental drinking-water supply to the recharge elevations and temperatures for groundwater indicate Vernal, Utah area. Red Fleet Reservoir, which was operated by that water in the Nugget Sandstone aquifer likely recharged at the Bureau of Reclamation and the Uintah Water Conservancy a high altitude and low temperature, and not locally because of District through 2015, began storing water in May 1980. interaction with Red Fleet Reservoir. The Frontier Sandstone The reservoir is on southward dipping Mesozoic lithologies aquifer is likely recharged at low elevation and at temperatures ranging from Jurassic to Cretaceous in age. The Nugget and similar to those observed at Red Fleet Reservoir. Frontier Sandstone aquifers are the targeted units in this investigation, which is to characterize groundwater conditions that exist in each sandstone aquifer and how they interact with Introduction Red Fleet Reservoir. Groundwater levels were measured in six wells and one spring in the Nugget Sandstone and the Frontier Red Fleet Reservoir (fig. 1) in Uintah County, Utah, Sandstone aquifers. Water levels in the Nugget Sandstone was completed in May 1980 and is operated primarily as aquifer were 35–70 feet above the maximum stage of Red an impoundment for irrigation water for the downstream Fleet Reservoir on the west and east banks. Water levels in community of Jensen, Utah as well as for Vernal, Utah. the Frontier Sandstone aquifer were 15–30 feet below the Red Fleet Reservoir can store up to approximately observed stage of Red Fleet Reservoir on the west bank during 26,000 acre-feet (acre-ft) of water at full stage. It also the study period. supplies water to the Ashley Valley Water Treatment Plant A water budget was calculated for Red Fleet Reservoir (AVWTP) in Vernal during spring runoff when Ashley Spring, between May 1980 and December 2015. During this period, the treatment plant’s primary water source, has elevated 1,050,000 acre-ft of water from Big Brush Creek discharged turbidity. The reservoir is an on-channel impoundment of Big into the reservoir, while 993,000 acre-ft of water was released Brush Creek and has not been previously investigated with downstream of Red Fleet Dam. Total evaporation from respect to the reservoir’s interaction with the surrounding May 1980 through December 2015 was about 52,000 acre-ft, groundwater systems. The geology of the region was while total precipitation over the same period was about studied in the 1960s by the Bureau of Reclamation (BOR) to 12,000 acre-ft. From May 1980 through December 2015, the investigate the feasibility of future dam sites for Red Fleet total pumped volume of water from the Tyzack Pump Station, Reservoir (Thompson, 1969). Extensive characterization of at the base of Red Fleet Dam, was about 42,000 acre-ft. Total local geology around the reservoir site was attained by field groundwater discharge to Red Fleet Reservoir from 1980 mapping as well as multiple drilled test holes. The Uintah through 2015 was about 40,000 acre-ft. Water Conservancy District (UWCD) and the BOR are Water was sampled from four wells and from the interested in evaluating the groundwater resources surrounding inflow arm of Red Fleet Reservoir, and analyzed for the reservoir as well as the surface-water/groundwater major-ion chemistry, selected trace metals, nutrients, and interactions that occur in Red Fleet Reservoir to better environmental tracers. Water sampled from the Nugget understand how the resources could be managed in the future Sandstone aquifer yielded good-quality water with dissolved- if groundwater withdrawals were initiated. solids concentrations of less than 200 milligrams per liter, 2 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

10935 10930 10925 10920

15

80 Salt ae City Vernal Brush Creek Spring 40 Study area

U T A H 70

15

Ashley Spring U.S. HIGHWAY 191 Red Fleet Reservoir 4035

Well (D-3-21)20bac-1

Well (D-3-21)20ccc-1

Ashley Valley Water Treatment Plant 4030

Vernal

Vernal Airport weather station

4025

Natural Resources Conservation Service (NRCS) EPLANATION Split Mountain weather station Well and identifier Water treatment plant Weather station Jensen

ase modified from U.S. Geological Survey and other 0 2.5 5 MIES Federal and state digital data, 1:185,0000 scale Universal Transverse Mercator proection one 12 Central Meridian –111 orth American atum of 192 0 2.5 5 KIMETERS

Figure 1. Location of the Red Fleet Reservoir study area, Uintah County, Utah. Assessment of Groundwater Interaction with Red Fleet Reservoir 3

The objectives of this report are to present and interpret include stream inflow from Big Brush Creek, stream outflow (1) groundwater levels, reservoir altitude, meteorological from dam releases and spillway discharge, reservoir and data, and inflows/outflows to and from Red Fleet Reservoir monitoring-well water levels, meteorological parameters, and from May 1980 through December 2015 for the purpose pumpage from the Tyzack Pump Station to the nearby AVWTP of estimating groundwater recharge/discharge to and from and irrigation distribution systems (figs. 1 and 2). surrounding aquifer units; (2) aquifer properties of the Nugget Sandstone near Red Fleet Reservoir from a two-well aquifer test; and (3) groundwater and surface-water chemical data to Surface-Water Inflow to and Outflow from Red evaluate the origin of groundwater in aquifer units adjacent to Fleet Reservoir Red Fleet Reservoir. This study is a cooperative effort by the UWCD, the BOR, and the U.S. Geological Survey (USGS). Big Brush Creek is the only perennial source of surface- water inflow to Red Fleet Reservoir. Big Brush Creek is predominantly supplied by Brush Creek Spring, which is Hydrogeology about 4 miles (mi) upstream of the U.S. Highway 191 bridge over Big Brush Creek (fig. 1). The spring is the primary Red Fleet Reservoir is on southward dipping Mesozoic discharge point for karst features that are developed in lithologies ranging in age from Jurassic to Cretaceous. The Paleozoic carbonate lithologies on the south slope of the Uinta geologic units dip southward at approximately 20–30 degrees. Mountains. Other small ephemeral streams that drain into the Formations crop out from north to south and include the reservoir, Cottonwood Wash being the largest, only contribute Jurassic Nugget Sandstone, Carmel Formation, Entrada small amounts of discharge during spring runoff in above Sandstone, Curtis Formation, Morrison Formation, Cretaceous average precipitation years and during intense monsoonal Dakota Sandstone, Mowry Shale, Frontier Sandstone, and precipitation events. The USGS has operated a streamgage Mancos Shale (Thompson, 1969). The Nugget Sandstone on Big Brush Creek since 1939; from 1939 to 1979 the gage aquifer is utilized regionally for drinking water near Vernal, (USGS 09262000, now inundated by Red Fleet Reservoir) was Utah. East/west jointing observed in the Frontier Sandstone located along the historic Donkey Flats Road where it crossed may result in enhanced secondary permeability in relation Big Brush Creek. As a result of the implementation of Red to groundwater/surface-water interaction with Red Fleet Fleet Reservoir, the streamgaging site for Big Brush Creek Reservoir. Geologic units other than the Nugget Sandstone and was moved upstream near U.S. Highway 191 where it crosses Frontier Sandstone generally are characterized by fine-grained Big Brush Creek in order to avoid inundation. This USGS site lithologies such as siltstones and shales and likely act as low- (09261700) has been operated continuously since 1979. permeability barriers to groundwater flow. From 1980 through 2015, Big Brush Creek discharged an average of 29,200 acre-feet per year (acre-ft/yr) of water to Red Fleet Reservoir. Maximum and minimum annual Assessment of Groundwater discharge from Big Brush Creek to Red Fleet Reservoir from 1980 through 2015 was 49,000 and 12,200 acre-ft, Interaction with Red Fleet Reservoir respectively, with the minimum year in 2002 and the maximum year in 1998 (fig. 3). To estimate groundwater interactions between Red Streamflow discharge from Red Fleet Reservoir is Fleet Reservoir and the underlying sandstone aquifers, an controlled by gates and jet valves at the base of Red Fleet annual surface-water budget for the reservoir was developed. Dam as well as a spillway on the east abutment. The discharge The calculation of the reservoir water budget included works have been operated continuously by the BOR or the reservoir inflows and outflows, changes in reservoir storage, UWCD since the reservoir first started filling in May 1980. evapotranspiration, and precipitation, with calculated residual A record of daily discharge has been maintained in the form values representing groundwater interactions with the of a written log book from which the data for this study were reservoir. The reservoir water budget covers the length of time obtained (John Hunting, Uintah Water Conservancy District, that Red Fleet Reservoir has been in operation (May 1980 written commun., 2016). Water from the reservoir has only through December 2015). discharged over the spillway for a short period during above- average spring runoff conditions in June 1984 and was not quantified in the water budget. For all other periods during Data Collection Methods and Results the operational record of the dam, discharge is well quantified through the logged record of discharge gate and valve settings. Many types of data have been collected as part of routine operations associated with Red Fleet Reservoir. These data 4 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

10928 1092 1092 10925 10924 TRd TRc Cottonwood Wash 403 TRn TRm Qe

sc Qae CottonwooodSpr DONKEY FLATS ROAD

PIPw U.S. HIGHWAY 191 TRc sc TRm TRn Big Brush Creek DH-111 Qe Qae sc USGS 09261700 Qae TRc (Big Brush Creek) RF1 sc Qas2 RFSPPump Qae Kcm

4035 TRn Kcm Kcm Red Fleet Reservoir OLD DONKEY FLATS ROAD Kmd sc Kf DH-121

Qas2 Kf Qac Big Brush Creek Kcm DH-109 Qas2 RF2 Tyack Pump Station Kmd Kf Kms

Qal 4034 Qas2

Kms

Kms Qal Kms ase modified from U.S. Geological Survey and other 0 0.5 1 MIE Federal and state digital data, various scales Universal Transverse Mercator proection one 12 Central Meridian –111 orth American atum of 192 0 0.5 1 KIMETER

EPLANATION Kms Mancos Shale

Kf Frontier Sandstone

Kmd Mowry Shale and Dakota Sandstone

Kcm Cedar Mountain and Morrison Formations

sc Stump Formation, Entrada Sandstone, and Carmel Formation TRn Nugget Sandstone

TRc Chinle Formation

USGS 09261700 (Big Brush Creek) USGS streamgage and identifier RF2 USGS well and identifier

Tyack Pump Station Pump station and identifier

Figure 2. Geology and location of wells, streamgage, and pump station near Red Fleet Reservoir, Utah. Assessment of Groundwater Interaction with Red Fleet Reservoir 5

55,000

EPLANATION Inflow Evaporation 45,000 Dam Groundwater recharge/ releases discharge Pumped outflow 35,000

25,000

, in acre-feet Volume 15,000

5,000

0

−5,000 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2015 Year

Figure 3. Annual inflows and outflows to and from Red Fleet Reservoir, near Vernal, Utah, 1980–2015.

Pumped Outflow from Red Fleet Reservoir of water pumped from the Tyzack Pump Station from 1980 through 2015 was about 42,500 acre-ft (table 1). Beginning in The Tyzack Pump Station is at the base of Red Fleet 1994, a diversion was built into the pipeline that connects the Dam and is operated by the UWCD (fig. 1). Pumping from Tyzack Pump Station and AVWTP. The UWCD utilized this the station first occurred during the early summer of 1986 to pipeline to supply irrigation water to users in Ashley Valley. provide water to the AVWTP (Brad Grammar, Ashley Valley This diversion was used in the summers of 1994, 1996, 1997, Water Treatment Plant, written commun., 2016). Pumping to and every summer between 2000 and 2015. During the years provide water to the AVWTP occurred every early summer when the irrigation diversion was used, the annual volume of from 1988 to 2015. The average annual pumped volume water diverted from the pipeline for irrigation ranged from 58 of water from the Tyzack Pump Station during years when to 1,078 acre-ft. pumping occurred was about 1,400 acre-ft. The total volume 6 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

- σ 4.01 4.29 0.59 1.35 2.08 0.75 2.68 3.71 11.97 53.28 19.37 17.97 52.53 53.39 12.84 15.66 28.47 24.42 13.77 12.88 26.35 21.02 34.00 93.18 46.89 34.49 140.78 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 10.04 10.09 10.35 10.30 10.42 10.24 10.13 10.05 10.05 10.13 10.50 10.25 10.20 10.29 10.33 10.33 10.39 10.68 10.13 10.10 10.08 10.13 10.54 10.31 10.11 10.35 10.38 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 31.11 180.12 178.45 389.98 658.73 402.58 630.60 743.41 606.58 823.63 715.27 701.96 958.93 –833.80 –166.11 –494.51 –419.93 –630.60 –986.39 8,237.24 4,462.29 1,104.63 1,230.58 4,914.45 change storage Monthly –1,279.08 –1,579.03 –1,379.13 reservoir (acre-feet) - 0.14 0.00 0.05 0.08 0.07 0.04 0.06 0.00 0.01 0.01 0.13 0.08 0.12 0.01 0.05 0.06 0.08 0.36 0.03 0.03 0.04 0.02 0.11 0.02 0.09 0.02 0.06 (feet) Monthly tion rate precipita - 0.38 0.59 0.71 0.55 0.35 0.17 0.04 0.03 0.02 0.04 0.12 0.28 0.38 0.62 0.70 0.56 0.38 0.15 0.05 0.01 0.00 0.04 0.11 0.19 0.39 0.55 0.68 (feet) . Monthly tion rate evapora - 149 321 333 313 302 303 307 314 315 320 330 343 358 359 342 314 300 299 312 323 334 341 351 370 384 447 440 Res area ervoir (acres) surface 39 43 –6 13 –7 27 528 513 133 –20 –35 –118 –187 –172 –527 –122 –153 –279 –237 –124 –247 –209 –330 –922 –453 –332 (–) –1,403 Monthly recharge/ discharge (acre-feet) groundwater - 0 0 3 4 2 8 5 7 8 11 20 16 24 22 13 17 43 27 44 16 19 24 12 40 33 26 109 tion feet) (acre- Monthly precipita - 8 5 5 0 57 50 13 13 40 96 46 16 12 39 69 114 191 236 171 106 135 223 241 177 151 248 297 tion feet) (acre- Monthly evapora 0 - 8,237 9,926 Res feet) ervoir (acre- 11,211 11,866 11,031 11,389 11,779 11,436 12,700 10,587 10,421 12,438 13,669 14,071 13,651 12,072 10,693 10,062 10,693 12,043 12,867 13,582 14,284 15,243 20,157 20,188 19,202 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 outflows (acre-feet) AVWTP Monthly pumped - 0 0 97 119 345 632 535 227 184 593 123 359 3,113 4,117 2,959 5,899 3,491 1,494 1,034 1,163 4,165 3,807 3,571 2,792 1,734 3,980 3,612 flow Monthly Dam out Red Fleet (acre-feet) 918 863 710 639 718 914 863 750 700 604 666 9,830 2,690 2,020 1,240 1,090 2,310 4,380 3,370 2,350 1,550 1,070 1,050 8,090 3,430 3,070 11,080 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,494.2 5,561.6 5,576.6 5,574.05 5,569.95 5,569.4 5,567.7 5,571.4 5,571.98 5,572.55 5,573.78 5,575.81 5,579.45 5,580.6 5,579.4 5,574.69 5,570.3 5,568.2 5,570.3 5,572.7 5,574.6 5,577.1 5,579.2 5,581.2 5,583.84 5,595.94 5,596.03 5,593.76 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015 Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

1. Month/year Empty stage May-80 June-80 July-80 August-80 September-80 October-80 November-80 December-80 January-81 February-81 March-81 April-81 May-81 June-81 July-81 August-81 September-81 October-81 November-81 December-81 January-82 February-82 March-82 April-82 May-82 June-82 July-82 Table Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, Assessment of Groundwater Interaction with Red Fleet Reservoir 7

- σ 9.93 9.07 1.46 9.42 5.39 0.37 11.13 24.86 28.69 18.23 36.16 92.21 19.64 39.81 46.00 55.54 30.40 47.82 25.94 14.84 58.39 44.95 20.82 36.99 37.77 118.79 110.06 100.67 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 10.40 10.68 10.31 10.19 10.16 10.10 10.33 10.29 10.25 10.15 10.08 10.21 10.39 10.27 10.15 10.21 10.08 10.02 10.03 10.16 10.29 10.09 10.14 10.38 10.32 10.30 10.16 10.09 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 44.83 67.36 31.48 86.76 111.06 147.71 717.90 –66.08 –649.77 –863.60 –165.84 –477.04 1,949.66 1,494.36 2,144.29 2,783.37 6,592.99 1,180.39 change storage Monthly –1,115.34 –1,330.88 –1,332.00 –2,162.06 –1,892.58 –1,014.66 –1,410.36 –1,586.80 –1,562.42 –1,533.94 reservoir (acre-feet) - 0.05 0.23 0.15 0.08 0.08 0.05 0.08 0.06 0.11 0.11 0.08 0.06 0.06 0.07 0.07 0.13 0.09 0.03 0.02 0.03 0.06 0.03 0.12 0.10 0.03 0.09 0.09 0.06 (feet) Monthly tion rate precipita - 0.59 0.35 0.14 0.03 0.01 0.00 0.02 0.13 0.17 0.35 0.54 0.66 0.60 0.37 0.18 0.04 0.00 0.00 0.00 0.07 0.19 0.44 0.55 0.70 0.57 0.35 0.15 0.04 (feet) Monthly tion rate evapora - 511 423 414 442 451 454 455 457 472 457 460 520 521 487 462 449 443 428 419 418 418 448 528 519 495 476 449 442 Res area ervoir (acres) surface 4 89 –93 –14 350 –92 300 257 –54 364 –239 –278 –181 –896 –192 –392 –998 –450 –535 –469 –146 –108 –579 –435 –202 –374 (–) –1,171 –1,061 Monthly recharge/ discharge (acre-feet) groundwater - 8 11 22 93 65 35 37 21 36 29 51 52 39 30 29 33 32 57 42 12 25 15 66 51 16 42 39 25 tion feet) (acre- Monthly precipita - 3 2 0 0 0 11 61 13 61 78 82 19 29 80 66 16 251 144 160 283 343 306 182 197 289 361 284 167 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 17,871 18,019 19,968 20,686 20,731 20,799 20,830 22,324 20,992 23,137 25,920 25,270 24,407 22,245 20,352 20,463 19,348 18,333 18,167 18,101 18,188 24,781 25,961 24,551 22,964 21,402 19,868 19,391 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 outflows (acre-feet) AVWTP Monthly pumped - 192 486 502 419 3,281 1,494 1,214 1,202 2,627 4,990 8,567 4,271 3,865 3,612 1,965 2,460 2,460 1,320 1,355 1,696 4,953 5,621 4,545 3,410 3,083 2,380 flow 11,388 16,652 Monthly Dam out Red Fleet (acre-feet) 859 1,940 1,600 1,860 1,270 1,210 1,070 1,050 1,130 6,850 7,780 3,150 1,760 2,070 1,570 1,560 1,380 1,150 1,160 1,730 3,460 2,790 1,770 1,940 1,520 11,150 11,620 18,680 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,590.58 5,590.94 5,595.53 5,597.15 5,597.25 5,597.4 5,597.47 5,600.72 5,597.83 5,602.43 5,608.02 5,606.75 5,605.03 5,600.55 5,596.4 5,596.65 5,594.1 5,591.7 5,591.3 5,591.14 5,591.35 5,605.78 5,608.1 5,605.32 5,602.07 5,598.73 5,595.3 5,594.2 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year August-82 September-82 October-82 November-82 December-82 January-83 February-83 March-83 April-83 May-83 June-83 July-83 August-83 September-83 October-83 November-83 December-83 January-84 February-84 March-84 April-84 May-84 June-84 July-84 August-84 September-84 October-84 November-84 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, 8 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

- σ 6.57 5.36 1.28 4.03 0.14 6.28 9.89 6.59 7.97 8.37 70.42 25.29 12.22 58.64 28.23 34.02 12.60 13.40 15.17 12.32 13.05 45.71 41.12 13.35 12.63 14.75 133.01 142.01 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 10.19 10.05 10.03 10.28 10.13 10.10 10.38 10.51 10.33 10.32 10.13 10.18 10.07 10.03 10.17 10.40 10.15 10.08 10.14 10.38 10.34 10.26 10.20 10.04 10.01 10.06 10.17 10.28 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 0.00 45.28 913.21 176.92 –93.51 328.53 830.07 910.63 165.93 294.13 276.90 –128.86 –481.45 –756.57 –795.34 –822.00 2,770.23 2,756.54 4,103.22 1,888.89 change storage Monthly –1,662.28 –1,430.04 –2,500.14 –1,249.56 –1,310.74 –2,186.16 –2,042.69 –1,555.12 reservoir (acre-feet) - 0.10 0.03 0.02 0.07 0.03 0.07 0.08 0.09 0.00 0.16 0.08 0.09 0.04 0.02 0.03 0.09 0.18 0.10 0.04 0.08 0.10 0.16 0.14 0.01 0.01 0.03 0.07 0.09 (feet) Monthly tion rate precipita - 0.00 0.00 0.00 0.08 0.26 0.43 0.60 0.70 0.55 0.30 0.15 0.03 0.00 0.00 0.05 0.17 0.22 0.36 0.60 0.62 0.55 0.30 0.15 0.04 0.01 0.00 0.03 0.09 (feet) Monthly tion rate evapora - 435 445 449 449 474 517 522 507 498 474 450 430 430 440 453 461 449 468 520 510 490 459 443 434 414 404 409 413 Res area ervoir (acres) surface –1 96 65 78 81 118 691 –65 –52 132 –13 –40 –61 147 –252 –121 –565 –269 –329 –122 –149 –129 –453 –396 –133 –126 (–) –1,318 –1,400 Monthly recharge/ discharge (acre-feet) groundwater - 7 2 7 3 5 43 13 31 15 35 41 47 74 37 37 15 14 42 83 47 20 43 49 74 61 13 27 36 tion feet) (acre- Monthly precipita - 1 0 1 1 0 3 2 35 68 15 24 76 98 67 18 12 36 126 223 315 357 275 143 169 312 317 268 138 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 20,113 19,262 20,175 20,352 20,352 23,122 25,879 25,397 24,641 22,979 21,548 19,048 18,955 19,283 21,024 21,069 19,820 23,923 25,812 24,501 22,315 20,272 19,477 18,655 17,100 17,266 17,560 17,837 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 17 76 outflows 287 334 (acre-feet) AVWTP Monthly pumped - 821 325 856 307 278 989 833 922 1,055 1,168 2,530 4,692 3,775 4,109 3,343 3,997 1,398 1,302 6,183 8,792 4,552 4,422 3,746 3,074 2,680 3,043 flow 11,243 10,006 Monthly Dam out Red Fleet (acre-feet) 974 1,340 1,160 1,120 5,290 3,920 3,060 2,390 1,860 1,660 1,270 1,130 1,130 1,050 1,500 4,820 3,120 2,410 1,940 2,350 1,740 1,360 1,290 1,190 1,280 11,120 12,870 12,850 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,593.9 5,596 5,596.4 5,596.4 5,602.4 5,607.94 5,607 5,605.5 5,602.1 5,599.05 5,593.4 5,593.18 5,593.95 5,595.86 5,597.9 5,598 5,595.19 5,604.05 5,607.81 5,605.22 5,600.7 5,596.22 5,594.4 5,592.47 5,588.67 5,589.09 5,589.82 5,590.5 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year December-84 January-85 February-85 March-85 April-85 May-85 June-85 July-85 August-85 September-85 October-85 November-85 December-85 January-86 February-86 March-86 April-86 May-86 June-86 July-86 August-86 September-86 October-86 November-86 December-86 January-87 February-87 March-87 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, Assessment of Groundwater Interaction with Red Fleet Reservoir 9

- σ 6.01 9.77 5.99 7.95 7.46 5.17 0.15 1.06 4.26 0.65 14.32 85.10 74.35 40.66 50.33 22.61 21.63 15.86 13.26 20.78 34.74 48.90 36.01 15.54 25.57 27.26 44.68 42.53 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 10.12 10.11 10.30 10.43 10.42 10.22 10.37 10.27 10.12 10.07 10.04 10.31 10.32 10.15 10.32 10.35 10.28 10.42 10.51 10.15 10.05 10.05 10.05 10.37 10.18 10.20 10.35 10.29 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 152.67 232.57 247.56 195.83 201.48 –53.46 347.15 613.14 621.32 532.41 662.29 –313.70 –575.16 2,984.22 4,479.71 1,821.32 3,362.59 1,192.45 change storage Monthly –1,464.10 –1,339.20 –1,871.59 –1,584.04 –2,402.46 –2,886.37 –1,042.88 –1,540.81 –2,341.54 –3,191.43 reservoir (acre-feet) - 0.01 0.12 0.02 0.17 0.14 0.01 0.13 0.10 0.05 0.03 0.01 0.02 0.13 0.07 0.04 0.01 0.02 0.07 0.00 0.01 0.02 0.02 0.01 0.02 0.01 0.02 0.10 0.01 (feet) Monthly tion rate precipita - 0.24 0.40 0.59 0.63 0.51 0.34 0.18 0.04 0.01 0.00 0.01 0.11 0.27 0.41 0.61 0.68 0.54 0.33 0.20 0.04 0.00 0.00 0.01 0.15 0.27 0.41 0.54 0.70 (feet) Monthly tion rate evapora - 427 507 519 498 489 462 441 441 444 447 451 453 464 509 516 486 451 422 416 418 425 434 442 450 462 460 435 390 Res area ervoir (acres) surface 6 58 97 60 78 74 51 –1 10 211 157 129 201 151 246 259 –41 –141 –842 –722 –390 –483 –221 –342 –474 –348 –439 –417 (–) Monthly recharge/ discharge (acre-feet) groundwater - 2 5 3 8 7 0 5 8 9 4 8 2 3 11 63 84 67 56 45 21 13 62 36 18 10 29 10 45 tion feet) (acre- Monthly precipita - 3 0 3 1 0 3 80 19 49 84 18 65 104 204 305 316 247 157 127 209 312 332 244 138 123 187 236 273 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 20,821 25,301 24,987 23,523 22,184 20,312 19,737 19,890 20,122 20,370 20,566 20,767 22,588 25,951 24,367 21,965 19,078 18,035 17,982 18,329 18,942 19,563 20,096 20,758 21,951 20,410 18,068 14,877 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 49 outflows 425 218 109 120 414 (acre-feet) AVWTP Monthly pumped - 893 648 615 575 615 931 505 369 246 246 222 246 1,286 8,401 5,352 4,481 3,742 3,570 1,743 4,946 5,023 4,676 3,856 1,530 2,416 4,900 3,662 4,091 flow Monthly Dam out Red Fleet (acre-feet) 946 831 986 904 807 926 910 752 976 4,230 4,610 2,860 2,100 1,630 1,250 1,230 1,020 3,020 8,140 3,260 2,300 1,780 1,060 3,290 3,120 1,590 1,590 12,180 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,597.45 5,606.81 5,606.19 5,603.23 5,600.42 5,596.31 5,595 5,595.35 5,595.88 5,596.44 5,596.88 5,597.33 5,601.28 5,608.08 5,604.95 5,599.95 5,593.47 5,590.98 5,590.85 5,591.69 5,593.15 5,594.6 5,595.82 5,597.31 5,599.92 5,596.53 5,591.06 5,582.85 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year April-87 May-87 June-87 July-87 August-87 September-87 October-87 November-87 December-87 January-88 February-88 March-88 April-88 May-88 June-88 July-88 August-88 September-88 October-88 November-88 December-88 January-89 February-89 March-89 April-89 May-89 June-89 July-89 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, 10 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

- σ 5.42 6.31 1.20 8.02 9.14 6.41 6.55 8.82 0.39 4.58 2.31 2.17 9.16 6.22 2.72 0.83 9.88 5.13 11.62 11.76 13.78 10.60 34.43 12.76 24.83 54.83 54.48 12.28 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 10.29 10.35 10.42 10.18 10.02 10.04 10.15 10.35 10.21 10.14 10.42 10.31 10.26 10.47 10.60 10.17 10.10 10.03 10.11 10.40 10.56 10.11 10.22 10.33 10.35 10.36 10.24 10.13 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un –44.41 393.20 505.41 713.21 714.64 787.37 903.72 –18.01 608.87 620.41 535.33 491.50 714.43 896.50 158.76 –946.71 –509.78 –558.84 2,320.48 2,348.74 5,374.89 1,393.27 change storage Monthly –2,313.38 –2,850.79 –2,331.58 –2,770.33 –1,516.17 –1,123.94 reservoir (acre-feet) - 0.06 0.05 0.04 0.03 0.01 0.01 0.05 0.02 0.10 0.03 0.18 0.01 0.01 0.08 0.16 0.03 0.04 0.01 0.01 0.06 0.11 0.03 0.05 0.02 0.07 0.08 0.06 0.02 (feet) Monthly tion rate precipita - 0.53 0.35 0.18 0.05 0.00 0.01 0.01 0.13 0.27 0.39 0.59 0.67 0.54 0.39 0.16 0.04 0.00 0.00 0.03 0.09 0.19 0.38 0.57 0.66 0.52 0.33 0.18 0.03 (feet) Monthly tion rate evapora - 355 325 320 323 330 340 351 363 382 417 448 425 390 370 366 370 380 389 396 405 415 448 517 491 469 450 441 435 Res area ervoir (acres) surface 53 63 63 64 83 –4 22 59 26 –8 50 111 133 104 –12 –79 –88 124 237 –45 –23 –88 –95 121 –113 –340 –542 –533 (–) Monthly recharge/ discharge (acre-feet) groundwater - 2 3 7 5 2 3 3 8 11 11 21 18 18 38 12 80 29 59 12 14 23 46 14 23 32 35 25 10 tion feet) (acre- Monthly precipita - 1 3 3 0 0 59 15 48 59 14 10 37 78 81 13 112 187 104 162 266 284 212 144 169 295 325 245 148 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 11,617 11,572 11,965 12,563 12,471 13,184 13,899 14,686 17,007 19,355 20,259 17,408 15,077 14,567 14,549 15,158 15,778 16,313 16,805 17,519 18,416 23,791 25,184 22,414 20,898 20,339 19,215 19,374 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 outflows 294 127 129 105 264 (acre-feet) AVWTP Monthly pumped - 0 0 41 99 44 111 717 238 171 980 875 129 123 103 678 4,011 3,051 1,528 2,953 4,348 3,848 1,468 2,977 5,504 4,667 3,691 2,471 2,108 flow Monthly Dam out Red Fleet (acre-feet) 936 831 740 738 742 621 740 940 736 661 632 631 684 962 1,250 3,430 6,170 3,930 1,840 1,850 1,440 1,090 8,070 6,900 2,240 2,380 1,930 1,090 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,576.19 5,573.27 5,573.13 5,574.36 5,575.91 5,578.04 5,580.11 5,582.32 5,588.44 5,594.11 5,596.19 5,589.44 5,583.39 5,581.99 5,581.94 5,583.61 5,585.27 5,586.67 5,587.93 5,589.72 5,591.9 5,603.78 5,606.58 5,600.91 5,597.62 5,596.37 5,593.79 5,594.16 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year August-89 September-89 October-89 November-89 December-89 January-90 February-90 March-90 April-90 May-90 June-90 July-90 August-90 September-90 October-90 November-90 December-90 January-91 February-91 March-91 April-91 May-91 June-91 July-91 August-91 September-91 October-91 November-91 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, Assessment of Groundwater Interaction with Red Fleet Reservoir 11

- σ 8.54 7.47 2.93 2.73 2.96 3.15 1.27 7.81 5.14 1.37 8.67 3.02 2.99 23.56 78.22 14.00 13.33 21.72 10.94 14.07 61.39 31.58 12.00 18.16 14.55 15.27 10.93 289.37 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 10.06 10.06 10.24 10.47 10.14 10.15 10.34 10.47 10.29 10.33 10.36 10.22 10.16 10.20 10.27 10.61 10.30 10.10 10.16 10.32 10.38 10.25 10.32 10.13 10.01 10.04 10.29 10.39 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 81.99 –90.21 –25.73 171.90 214.75 582.19 377.67 351.64 858.21 –73.51 353.72 149.34 423.01 514.63 649.97 –695.75 –930.28 3,328.55 3,100.61 3,729.50 1,910.47 change storage Monthly –2,081.38 –1,549.00 –2,846.27 –1,580.66 –3,090.21 –1,222.79 –2,056.88 reservoir (acre-feet) - 0.02 0.02 0.04 0.05 0.01 0.11 0.05 0.14 0.06 0.05 0.08 0.05 0.06 0.06 0.08 0.16 0.07 0.09 0.07 0.02 0.08 0.04 0.21 0.03 0.00 0.00 0.08 0.02 (feet) Monthly tion rate precipita - 0.00 0.00 0.03 0.13 0.28 0.41 0.52 0.55 0.51 0.34 0.18 0.03 0.00 0.00 0.00 0.09 0.18 0.43 0.53 0.62 0.51 0.34 0.12 0.02 0.00 0.01 0.02 0.13 (feet) Monthly tion rate evapora - 411 435 434 435 437 453 514 512 482 455 426 407 405 419 423 431 440 456 510 491 467 440 419 417 420 424 430 439 Res area ervoir (acres) surface 85 74 30 76 13 84 29 117 –29 –26 –29 –12 135 130 –50 176 144 153 109 –29 –232 –771 –214 –107 –133 –608 –304 (–) –2,849 Monthly recharge/ discharge (acre-feet) groundwater - 9 9 6 0 0 11 16 24 58 26 68 28 22 34 21 24 27 34 68 30 40 33 39 18 89 14 34 10 tion feet) (acre- Monthly precipita - 1 0 0 1 1 8 1 6 8 11 15 55 73 38 81 51 57 211 128 265 267 231 145 197 269 303 240 150 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 19,283 19,258 19,430 19,512 22,840 25,941 23,859 22,310 19,464 17,883 17,188 17,402 17,985 18,362 18,714 19,572 19,499 23,228 25,139 22,048 20,826 18,769 17,838 18,192 18,341 18,764 19,279 19,929 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 14 outflows 251 348 328 358 204 236 220 (acre-feet) AVWTP Monthly pumped - 40 815 720 468 706 422 286 375 319 438 518 266 222 143 1,521 5,937 3,663 2,922 3,878 2,154 1,353 1,745 7,696 8,602 4,614 3,606 3,158 2,073 flow Monthly Dam out Red Fleet (acre-feet) 801 760 610 793 976 831 758 630 619 588 735 930 821 803 682 869 4,740 8,670 2,140 1,930 1,580 1,750 8,120 1,900 2,280 1,350 1,280 11,210 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,593.95 5,593.89 5,594.29 5,594.48 5,601.81 5,608.06 5,603.92 5,600.69 5,594.37 5,590.61 5,588.89 5,589.43 5,590.86 5,591.77 5,592.61 5,594.62 5,594.45 5,602.62 5,606.49 5,600.13 5,597.46 5,592.74 5,590.5 5,591.36 5,591.72 5,592.73 5,593.94 5,595.44 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year December-91 January-92 February-92 March-92 April-92 May-92 June-92 July-92 August-92 September-92 October-92 November-92 December-92 January-93 February-93 March-93 April-93 May-93 June-93 July-93 August-93 September-93 October-93 November-93 December-93 January-94 February-94 March-94 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, 12 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

- σ 0.18 0.43 5.78 8.99 1.00 7.26 8.87 10.47 35.24 44.38 39.29 79.66 14.27 10.82 16.48 18.27 22.71 14.43 36.05 41.97 55.31 54.17 12.57 18.10 88.10 72.38 43.56 148.16 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 10.16 10.14 10.30 10.29 10.78 10.23 10.45 10.16 10.05 10.09 10.29 10.20 10.19 10.11 10.09 10.24 10.31 10.28 10.28 10.13 10.05 10.16 10.20 10.36 10.29 10.15 10.30 10.40 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 827.19 777.85 764.38 292.51 –53.09 436.10 478.21 498.85 566.94 415.49 –177.59 2,189.26 3,335.11 1,004.00 1,004.20 1,018.53 1,966.86 4,384.03 2,485.50 2,285.23 change storage Monthly –2,737.01 –4,561.54 –3,813.54 –2,555.71 –1,267.29 –2,777.05 –1,789.87 –2,479.87 reservoir (acre-feet) - 0.04 0.06 0.02 0.00 0.06 0.07 0.32 0.10 0.02 0.04 0.08 0.02 0.09 0.23 0.10 0.07 0.06 0.05 0.01 0.01 0.01 0.06 0.04 0.04 0.04 0.11 0.06 0.13 (feet) Monthly tion rate precipita - 0.24 0.44 0.62 0.67 0.56 0.35 0.13 0.02 0.01 0.01 0.07 0.11 0.19 0.29 0.50 0.63 0.60 0.37 0.16 0.06 0.02 0.01 0.03 0.10 0.19 0.31 0.53 0.72 (feet) Monthly tion rate evapora - 452 498 504 447 391 341 329 349 362 373 384 397 420 459 516 518 490 454 449 449 448 449 456 463 471 485 517 493 Res area ervoir (acres) surface 2 4 56 87 103 382 779 –89 –10 –71 121 176 –347 –431 –137 –106 –164 –181 –221 –141 –354 –415 –548 –526 –868 –703 –419 (–) –1,447 Monthly recharge/ discharge (acre-feet) groundwater - 9 1 8 8 6 3 2 17 32 23 23 33 14 30 39 51 38 29 24 27 19 19 17 52 29 63 106 107 tion feet) (acre- Monthly precipita - 8 2 5 9 3 44 26 44 78 72 26 14 47 90 107 218 315 299 218 120 131 260 328 296 167 151 272 353 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 22,118 11,786 24,511 25,453 22,716 18,155 14,341 12,790 13,794 14,621 15,399 16,163 17,182 19,149 23,533 26,018 24,751 21,974 20,184 20,476 20,299 20,246 20,682 21,160 21,659 22,226 24,927 22,447 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 52 642 tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 80 83 36 15 outflows 276 350 419 336 222 127 242 279 361 317 (acre-feet) AVWTP Monthly pumped - 674 298 307 307 278 307 996 984 504 288 307 1,115 1,379 5,290 4,861 5,171 4,439 2,420 5,970 7,918 5,236 3,253 1,174 1,099 4,655 4,403 4,681 flow 14,652 Monthly Dam out Red Fleet (acre-feet) 962 964 895 817 930 927 845 847 956 3,840 8,740 2,350 1,760 1,800 1,480 1,170 1,220 2,850 5,530 2,200 1,610 1,410 1,930 6,450 4,720 2,390 10,090 17,040 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,600.28 5,607.11 5,601.55 5,591.27 5,581.37 5,573.8 5,576.87 5,579.81 5,582.14 5,584.26 5,586.28 5,588.88 5,593.63 5,603.25 5,608.21 5,605.72 5,599.97 5,596.02 5,596.68 5,596.28 5,596.16 5,597.14 5,598.2 5,599.29 5,600.51 5,605.24 5,606.07 5,600.98 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year April-94 May-94 June-94 July-94 August-94 September-94 October-94 November-94 December-94 January-95 February-95 March-95 April-95 May-95 June-95 July-95 August-95 September-95 October-95 November-95 December-95 January-96 February-96 March-96 April-96 May-96 June-96 July-96 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, Assessment of Groundwater Interaction with Red Fleet Reservoir 13

- σ 8.42 3.92 5.60 1.99 4.86 9.77 6.87 6.16 1.33 1.02 23.10 12.32 68.28 13.09 84.85 19.19 39.96 20.70 10.24 13.96 10.18 42.65 25.51 94.46 22.80 87.80 38.13 228.90 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 10.37 10.81 10.49 10.22 10.11 10.25 10.16 10.17 10.16 10.07 10.22 10.28 10.40 10.40 10.22 10.06 10.07 10.08 10.27 10.33 10.23 10.06 10.12 10.40 10.33 10.25 10.37 10.22 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 35.57 116.97 279.27 316.77 325.79 390.44 289.87 186.30 429.05 –35.57 129.13 426.55 –82.70 –977.81 –356.95 –402.39 –523.18 4,190.18 1,514.51 1,576.90 5,080.04 change storage Monthly –3,325.95 –1,933.17 –3,408.50 –1,122.41 –1,475.48 –2,148.29 –2,287.25 reservoir (acre-feet) - 0.00 0.09 0.08 0.06 0.04 0.11 0.06 0.00 0.10 0.05 0.08 0.03 0.20 0.24 0.06 0.02 0.06 0.03 0.10 0.06 0.01 0.01 0.10 0.15 0.08 0.04 0.14 0.07 (feet) Monthly tion rate precipita - 0.58 0.26 0.15 0.03 0.01 0.00 0.00 0.11 0.13 0.31 0.48 0.48 0.39 0.26 0.15 0.03 0.00 0.01 0.03 0.11 0.24 0.41 0.52 0.72 0.58 0.41 0.18 0.05 (feet) Monthly tion rate evapora - 411 454 413 407 415 421 425 432 420 437 498 468 442 423 439 455 452 450 450 450 453 496 524 516 492 457 439 439 Res area ervoir (acres) surface 78 37 96 60 13 –55 –20 –48 –68 –99 939 –10 –223 –120 –672 –129 –831 –187 –384 –199 –102 –138 –413 –249 –225 –844 –369 (–) –2,274 Monthly recharge/ discharge (acre-feet) groundwater - 1 2 9 5 4 35 34 25 18 46 25 42 22 40 13 89 25 25 13 44 29 54 76 41 17 63 30 101 tion feet) (acre- Monthly precipita - 3 1 1 1 6 63 13 46 56 65 13 14 51 78 22 111 263 109 135 237 227 174 107 203 270 370 287 186 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 19,121 17,188 17,467 17,784 18,109 18,500 18,790 18,976 17,998 22,188 23,703 20,294 19,172 18,815 20,392 20,821 20,419 20,454 20,419 20,548 20,974 26,054 25,972 24,496 22,348 20,061 19,537 19,654 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 90 10 116 340 tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 42 47 outflows 106 224 324 358 217 172 270 (acre-feet) AVWTP Monthly pumped - 629 595 615 615 555 337 1,111 3,011 4,794 2,267 1,531 8,467 4,701 5,415 3,239 2,636 1,369 1,815 1,230 1,230 1,974 5,576 4,931 3,808 1,825 1,071 flow 11,712 13,932 Monthly Dam out Red Fleet (acre-feet) 974 845 906 841 774 946 968 1,730 1,050 1,090 1,960 5,940 2,340 2,000 2,090 2,050 1,700 1,320 1,120 2,300 3,550 2,660 1,750 1,330 1,170 10,820 18,200 13,840 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,593.57 5,588.89 5,589.59 5,590.37 5,591.16 5,592.1 5,592.79 5,593.23 5,590.89 5,600.43 5,603.6 5,596.27 5,593.69 5,592.85 5,596.49 5,597.45 5,596.55 5,596.63 5,596.55 5,596.84 5,597.79 5,608.28 5,608.12 5,605.21 5,600.77 5,595.74 5,594.54 5,594.81 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year August-96 September-96 October-96 November-96 December-96 January-97 February-97 March-97 April-97 May-97 June-97 July-97 August-97 September-97 October-97 November-97 December-97 January-98 February-98 March-98 April-98 May-98 June-98 July-98 August-98 September-98 October-98 November-98 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, 14 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

- σ 9.30 7.17 4.86 1.38 1.16 8.26 9.62 2.06 0.36 1.36 4.66 4.42 11.88 16.73 57.96 73.21 39.04 14.07 14.24 19.08 14.35 17.14 53.37 64.56 41.50 38.65 28.53 126.69 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 11.16 10.05 10.16 10.23 10.39 10.45 10.12 10.13 10.37 10.40 10.41 10.23 10.15 10.03 10.14 10.31 10.39 10.24 10.11 10.34 10.45 10.74 10.55 10.10 10.02 10.11 10.28 10.56 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 8.88 303.86 576.48 595.81 368.10 –66.84 –71.14 819.69 434.04 640.45 545.99 503.55 446.89 440.13 –811.94 –147.22 –485.34 –160.96 –137.44 2,268.68 2,150.64 4,941.66 change storage Monthly –2,038.56 –1,735.13 –1,741.04 –1,675.80 –3,649.26 –1,975.05 reservoir (acre-feet) - 0.02 0.07 0.05 0.00 0.15 0.13 0.02 0.06 0.17 0.09 0.01 0.01 0.01 0.04 0.08 0.05 0.05 0.04 0.02 0.02 0.04 0.14 0.14 0.03 0.00 0.04 0.06 0.04 (feet) Monthly tion rate precipita - 0.01 0.01 0.04 0.16 0.19 0.38 0.54 0.67 0.56 0.35 0.21 0.07 0.01 0.03 0.04 0.13 0.32 0.50 0.61 0.72 0.60 0.36 0.16 0.02 0.00 0.00 0.04 0.17 (feet) Monthly tion rate evapora - 411 438 438 446 453 461 470 519 506 482 470 458 453 451 450 449 449 448 506 515 492 455 404 413 421 428 435 441 Res area ervoir (acres) surface 4 11 92 13 20 13 117 –70 –47 –82 –91 –45 –42 –160 –573 –706 –376 –135 –140 –185 –138 –167 –528 –624 –397 –360 –256 (–) –1,250 Monthly recharge/ discharge (acre-feet) groundwater - 9 0 2 4 4 8 2 11 11 29 21 68 61 13 29 84 43 18 37 21 22 20 19 56 56 16 25 17 tion feet) (acre- Monthly precipita - 4 4 2 7 2 1 11 18 74 86 98 33 19 59 67 15 73 179 281 336 271 163 145 251 317 356 273 146 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 19,811 19,117 19,507 20,388 20,983 21,351 23,620 25,771 23,732 21,997 21,512 20,700 20,539 20,472 20,401 20,410 20,272 21,092 26,034 24,293 22,617 18,968 16,993 17,427 18,067 18,613 19,563 20,004 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 452 496 tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 34 66 outflows 226 206 283 205 (acre-feet) AVWTP Monthly pumped - 635 278 307 978 666 298 307 307 278 307 1,230 1,309 7,220 8,975 4,947 4,403 2,430 2,043 1,190 1,123 1,097 1,045 2,529 6,893 4,572 3,898 4,443 2,483 flow Monthly Dam out Red Fleet (acre-feet) 781 930 972 879 783 807 839 954 857 809 670 762 1,170 1,030 1,570 9,260 2,510 2,480 1,930 1,340 1,070 3,370 2,720 2,170 1,140 1,020 11,820 10,350 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,594.47 5,595.17 5,596.48 5,597.81 5,598.62 5,603.43 5,607.73 5,603.66 5,600.02 5,598.97 5,597.18 5,596.82 5,596.67 5,596.51 5,596.53 5,596.22 5,598.05 5,608.24 5,604.8 5,601.34 5,593.21 5,588.4 5,589.49 5,591.06 5,592.37 5,593.56 5,594.6 5,595.61 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year December-98 January-99 February-99 March-99 April-99 May-99 June-99 July-99 August-99 September-99 October-99 November-99 December-99 January-00 February-00 March-00 April-00 May-00 June-00 July-00 August-00 September-00 October-00 November-00 December-00 January-01 February-01 March-01 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, Assessment of Groundwater Interaction with Red Fleet Reservoir 15

- σ 9.25 9.08 6.61 2.01 5.54 8.84 5.85 6.95 5.33 6.72 11.03 77.48 78.75 27.85 10.32 15.01 46.97 15.95 23.33 26.97 10.78 19.01 35.87 100.87 186.15 296.01 201.37 128.60 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 11.22 11.05 11.80 10.29 10.08 10.45 10.60 10.95 10.73 10.36 10.20 10.00 10.01 10.05 10.44 10.44 10.53 10.93 10.48 10.23 10.05 10.09 10.25 10.46 10.19 10.15 10.35 10.77 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 22.35 620.41 643.46 572.58 484.99 587.22 –38.64 548.38 698.15 638.80 542.14 615.65 780.50 –123.96 –355.28 –669.97 –435.79 1,499.01 4,541.45 1,176.42 4,921.10 change storage Monthly –3,590.96 –4,881.93 –1,661.32 –2,951.76 –2,444.13 –2,600.28 –1,966.49 reservoir (acre-feet) - 0.10 0.02 0.03 0.08 0.08 0.01 0.07 0.02 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.03 0.00 0.19 0.07 0.08 0.03 0.04 0.08 0.07 0.01 0.16 0.09 0.00 (feet) Monthly tion rate precipita - 0.27 0.45 0.65 0.71 0.59 0.42 0.21 0.07 0.00 0.00 0.02 0.12 0.31 0.48 0.68 0.77 0.59 0.33 0.16 0.03 0.00 0.00 0.02 0.14 0.26 0.43 0.56 0.78 (feet) Monthly tion rate evapora - 453 506 521 490 455 421 393 398 407 416 423 431 437 426 390 345 308 281 281 286 297 307 317 327 338 374 431 419 Res area ervoir (acres) surface 91 91 66 57 753 743 269 103 –19 –50 –81 198 257 –69 –52 187 –66 –110 –144 –446 –142 –103 –333 (–) 1,877 –1,001 –1,781 –2,704 –1,242 Monthly recharge/ discharge (acre-feet) groundwater - 9 4 9 1 0 0 0 0 0 0 7 5 0 46 18 40 38 29 20 12 53 21 22 12 25 22 61 38 tion feet) (acre- Monthly precipita - 0 1 7 0 1 7 83 27 51 93 46 10 46 88 120 228 338 349 270 176 135 204 266 265 180 160 241 329 tion feet) (acre- Monthly evapora - 9,634 9,199 9,221 9,769 Res feet) ervoir (acre- 11,106 11,648 21,503 26,044 25,920 22,329 21,974 17,092 16,422 17,042 17,686 18,258 18,743 19,331 19,292 17,631 14,679 12,235 10,468 12,264 13,441 18,362 19,142 17,176 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 72 28 256 350 540 240 827 430 447 274 368 tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 60 78 85 72 outflows 279 259 263 210 145 (acre-feet) AVWTP Monthly pumped - 111 119 803 179 184 184 167 184 700 492 123 123 123 5,135 4,403 4,197 3,302 1,309 1,402 3,735 3,178 2,698 2,793 1,021 3,289 3,414 3,993 flow 10,602 Monthly Dam out Red Fleet (acre-feet) 962 908 918 861 724 783 887 739 776 797 712 704 682 583 660 3,190 3,700 2,120 1,720 1,010 1,440 2,330 1,440 2,540 8,480 3,300 2,390 14,640 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,598.95 5,608.26 5,608.02 5,600.73 5,599.97 5,588.65 5,586.95 5,588.53 5,590.13 5,591.52 5,592.68 5,594.06 5,593.97 5,589.99 5,582.3 5,575.19 5,566.74 5,565.15 5,565.23 5,567.16 5,569.53 5,571.62 5,573.37 5,575.28 5,578.79 5,591.77 5,593.62 5,588.86 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year April-01 May-01 June-01 July-01 August-01 September-01 October-01 November-01 December-01 January-02 February-02 March-02 April-02 May-02 June-02 July-02 August-02 September-02 October-02 November-02 December-02 January-03 February-03 March-03 April-03 May-03 June-03 July-03 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, 16 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

- σ 9.99 7.43 2.16 2.84 1.95 0.87 3.01 6.96 0.62 4.21 6.69 2.80 2.17 6.77 4.28 9.15 11.06 11.28 11.67 76.62 15.53 25.96 12.61 17.13 12.10 10.92 12.43 139.20 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 10.82 10.53 10.24 10.24 10.23 10.03 10.20 10.41 10.21 10.16 10.46 10.66 10.76 10.78 10.48 10.12 10.05 10.29 10.13 10.31 10.13 10.07 10.13 10.42 10.51 10.41 10.35 10.16 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 78.19 600.35 740.62 619.71 565.66 793.79 –235.06 –167.17 –893.04 –650.76 –156.23 2,307.66 2,365.43 2,213.86 1,213.04 1,124.35 1,205.32 6,406.86 1,941.49 change storage Monthly –1,110.28 –2,845.42 –1,653.98 –1,643.03 –1,442.47 –2,683.35 –1,630.53 –1,339.84 –1,430.37 reservoir (acre-feet) - 0.03 0.02 0.02 0.07 0.11 0.01 0.06 0.00 0.09 0.02 0.10 0.02 0.02 0.14 0.35 0.12 0.02 0.17 0.05 0.11 0.10 0.13 0.07 0.01 0.06 0.12 0.11 0.03 (feet) Monthly tion rate precipita - 0.62 0.38 0.25 0.03 0.01 0.00 0.02 0.22 0.27 0.44 0.56 0.66 0.54 0.35 0.17 0.04 0.01 0.01 0.04 0.13 0.25 0.43 0.50 0.71 0.55 0.37 0.19 0.06 (feet) Monthly tion rate evapora - 384 352 327 326 336 346 355 365 387 429 429 404 375 341 324 350 375 392 398 394 395 440 521 515 499 483 470 465 Res area ervoir (acres) surface 28 –9 –6 39 67 43 87 116 –92 –71 –21 –19 –29 –67 108 144 241 108 –27 –21 –66 105 122 –115 –754 –125 –164 (–) –1,374 Monthly recharge/ discharge (acre-feet) groundwater - 7 5 4 1 9 8 6 8 3 10 24 37 20 35 43 49 42 66 19 45 39 58 37 28 59 51 14 113 tion feet) (acre- Monthly precipita - 2 0 7 5 6 11 83 79 54 14 16 51 99 89 26 119 239 135 103 190 239 266 202 191 259 364 275 177 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 11,566 14,330 12,676 12,166 12,907 13,527 14,092 14,886 17,194 19,559 17,916 16,474 13,790 12,160 12,238 14,452 15,665 16,789 16,554 16,387 17,592 23,999 25,941 24,601 23,708 22,277 21,627 21,470 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 44 58 434 127 184 417 235 tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 62 93 74 29 21 outflows 236 253 222 (acre-feet) AVWTP Monthly pumped - 119 115 119 123 123 123 835 123 123 3,535 2,291 1,783 3,741 3,227 2,878 3,416 2,124 1,543 1,269 1,537 4,106 9,749 4,005 3,140 2,606 1,837 1,212 flow 10,284 Monthly Dam out Red Fleet (acre-feet) 821 730 734 809 730 639 928 1,260 3,320 5,770 1,880 2,010 1,490 1,040 1,670 2,180 1,400 1,160 1,010 1,310 5,330 2,890 2,660 1,410 1,330 1,190 17,120 10,760 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,581.33 5,576.53 5,573.11 5,574.98 5,577.22 5,579.04 5,580.66 5,582.87 5,588.91 5,594.58 5,590.69 5,587.08 5,579.8 5,574.96 5,575.2 5,581.67 5,584.97 5,587.89 5,587.29 5,586.86 5,589.9 5,604.07 5,608.06 5,605.42 5,603.61 5,600.62 5,599.22 5,598.88 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year August-03 September-03 October-03 November-03 December-03 January-04 February-04 March-04 April-04 May-04 June-04 July-04 August-04 September-04 October-04 November-04 December-04 January-05 February-05 March-05 April-05 May-05 June-05 July-05 August-05 September-05 October-05 November-05 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, Assessment of Groundwater Interaction with Red Fleet Reservoir 17

- σ 1.15 1.82 0.91 5.01 9.53 5.96 0.67 4.87 0.08 9.16 4.11 9.38 6.53 11.10 52.62 22.38 40.57 27.94 15.05 42.22 24.06 43.50 42.94 22.80 21.31 20.11 128.34 122.89 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 11.08 11.46 11.10 11.47 11.48 10.06 10.18 10.09 10.67 10.18 10.14 10.75 10.66 10.19 10.08 10.07 10.20 10.35 10.18 10.17 10.91 10.99 10.30 10.16 10.46 10.10 10.20 10.39 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un –27.50 437.96 669.67 885.11 842.85 771.40 691.88 646.44 686.99 701.69 679.72 764.29 804.08 –347.00 –779.64 –229.68 –247.91 2,009.39 1,035.20 1,739.64 3,734.76 change storage Monthly –1,754.27 –2,778.19 –3,165.42 –1,733.37 –2,859.50 –2,893.80 –2,321.39 reservoir (acre-feet) - 0.01 0.06 0.00 0.18 0.06 0.01 0.07 0.01 0.05 0.16 0.27 0.03 0.03 0.03 0.03 0.02 0.06 0.09 0.01 0.02 0.02 0.04 0.01 0.00 0.19 0.04 0.07 0.08 (feet) Monthly tion rate precipita - 0.01 0.01 0.03 0.11 0.29 0.49 0.72 0.75 0.60 0.36 0.18 0.07 0.01 0.00 0.04 0.18 0.27 0.46 0.70 0.79 0.66 0.42 0.20 0.08 0.00 0.00 0.01 0.08 (feet) Monthly tion rate evapora - 411 464 466 474 484 490 500 505 470 429 399 393 400 421 431 441 463 508 517 480 441 402 385 390 400 410 420 431 Res area ervoir (acres) surface 9 7 1 11 94 54 48 40 92 –18 –47 519 208 354 252 141 –90 387 210 396 374 221 –62 –110 –209 –194 (–) 1,261 1,209 Monthly recharge/ discharge (acre-feet) groundwater - 6 0 6 5 7 5 8 9 4 0 11 27 89 27 34 19 64 13 12 13 27 45 15 75 16 29 33 105 tion feet) (acre- Monthly precipita - 6 6 2 0 0 0 2 15 55 71 26 17 81 76 30 36 140 246 364 353 257 145 127 235 361 377 292 170 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 22,118 21,443 21,881 22,551 23,436 23,089 25,098 23,344 20,566 17,400 16,621 16,391 17,234 18,005 18,697 19,343 20,379 25,853 24,120 21,260 18,366 16,045 15,797 16,484 17,186 17,865 18,630 19,434 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 243 696 963 180 544 460 748 tion 1,078 Irriga 0 0 0 0 0 0 0 0 0 0 0 9 0 0 0 0 0 0 68 84 14 10 13 17 outflows 371 130 289 149 (acre-feet) AVWTP Monthly pumped - 952 476 139 154 137 141 141 128 141 149 154 154 144 154 4,363 5,881 3,499 3,796 2,850 1,317 1,192 1,759 3,588 3,777 3,390 2,876 2,037 1,125 flow Monthly Dam out Red Fleet (acre-feet) 936 875 833 958 952 823 688 958 718 708 672 768 4,290 9,020 2,610 2,130 1,250 1,050 1,070 1,000 1,290 4,990 9,010 3,480 2,200 1,130 1,010 1,170 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,598.82 5,599.77 5,601.2 5,603.05 5,602.33 5,606.41 5,602.86 5,596.88 5,589.42 5,587.46 5,586.87 5,589.01 5,590.91 5,592.57 5,594.09 5,596.46 5,600.28 5,607.89 5,604.45 5,598.42 5,591.78 5,585.97 5,585.32 5,587.11 5,588.89 5,590.57 5,592.41 5,594.3 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year December-05 January-06 February-06 March-06 April-06 May-06 June-06 July-06 August-06 September-06 October-06 November-06 December-06 January-07 February-07 March-07 April-07 May-07 June-07 July-07 August-07 September-07 October-07 November-07 December-07 January-08 February-08 March-08 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, 18 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

- σ 2.86 8.26 5.47 0.22 6.70 3.39 0.56 9.83 5.90 0.75 6.94 2.19 7.47 7.46 46.34 21.11 26.90 30.90 29.58 30.77 23.19 23.66 18.57 12.46 47.66 19.33 25.27 231.73 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 11.10 11.05 10.42 10.10 10.26 10.83 10.61 10.32 10.29 10.24 10.21 10.11 10.42 10.55 10.14 10.31 10.46 10.76 10.37 10.28 10.29 10.15 10.05 10.54 10.46 10.13 10.26 10.69 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 77.38 635.58 665.04 714.39 788.33 704.15 631.93 –18.35 314.45 271.88 297.00 151.77 184.85 929.49 –854.77 –613.64 –266.03 4,561.38 1,160.52 4,414.65 2,955.87 change storage Monthly –2,312.04 –3,193.70 –1,436.68 –1,004.77 –2,307.42 –1,426.60 –1,940.43 reservoir (acre-feet) - 0.03 0.00 0.12 0.01 0.15 0.09 0.06 0.05 0.09 0.09 0.02 0.02 0.09 0.05 0.11 0.01 0.04 0.09 0.05 0.03 0.09 0.05 0.01 0.04 0.12 0.05 0.13 0.07 (feet) Monthly tion rate precipita - 0.21 0.41 0.64 0.75 0.64 0.36 0.20 0.07 0.01 0.00 0.03 0.13 0.24 0.48 0.60 0.72 0.60 0.44 0.16 0.06 0.00 0.00 0.00 0.10 0.25 0.35 0.61 0.70 (feet) Monthly tion rate evapora - 441 474 520 505 471 438 420 421 430 441 451 460 465 497 524 519 496 468 455 455 459 463 465 468 472 499 522 503 Res area ervoir (acres) surface 2 27 76 53 66 –5 93 –7 67 22 74 119 459 242 291 287 –34 –58 294 210 220 179 –71 471 188 236 –206 (–) 2,248 Monthly recharge/ discharge (acre-feet) groundwater - 0 6 7 9 6 6 15 62 69 38 25 21 38 40 41 22 60 21 43 24 14 42 22 20 55 25 67 36 tion feet) (acre- Monthly precipita - 5 2 1 1 0 91 86 29 12 62 74 28 47 113 116 195 334 380 301 159 238 312 376 298 206 174 320 351 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 20,069 24,631 25,791 23,479 20,286 18,849 17,994 18,659 19,374 20,162 20,866 21,498 21,480 25,894 25,972 24,967 22,659 21,233 20,619 20,934 21,206 21,503 21,654 21,839 22,769 25,725 25,459 23,518 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 70 116 379 639 101 643 227 tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 40 22 24 24 42 68 38 44 57 outflows 304 222 275 139 265 295 (acre-feet) AVWTP Monthly pumped - 481 149 154 154 139 154 417 430 430 389 430 716 4,731 5,891 3,771 3,507 1,781 1,517 1,202 4,413 4,344 4,552 3,529 1,930 1,142 4,120 6,799 3,695 flow Monthly Dam out Red Fleet (acre-feet) 851 875 837 970 815 833 758 738 728 728 609 571 1,260 7,340 2,310 1,450 1,010 1,390 9,260 7,060 4,380 2,350 1,040 1,870 7,960 7,270 2,590 10,250 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,595.76 5,605.48 5,607.77 5,603.14 5,596.25 5,592.93 5,590.88 5,592.48 5,594.16 5,595.97 5,597.55 5,598.94 5,598.9 5,607.97 5,608.12 5,606.15 5,601.43 5,598.36 5,597 5,597.7 5,598.3 5,598.95 5,599.28 5,599.68 5,601.66 5,607.64 5,607.12 5,603.22 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year April-08 May-08 June-08 July-08 August-08 September-08 October-08 November-08 December-08 January-09 February-09 March-09 April-09 May-09 June-09 July-09 August-09 September-09 October-09 November-09 December-09 January-10 February-10 March-10 April-10 May-10 June-10 July-10 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, Assessment of Groundwater Interaction with Red Fleet Reservoir 19

- σ 3.76 7.31 7.93 1.99 9.31 0.48 3.50 8.22 0.97 9.33 32.36 35.26 16.55 13.83 14.38 72.83 20.51 31.04 25.28 14.67 10.93 20.70 21.84 15.13 35.91 37.49 170.56 191.66 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 11.02 11.30 11.24 11.06 11.25 10.77 10.32 10.56 10.00 10.19 10.24 10.31 10.12 10.12 10.45 10.79 10.34 10.45 10.20 10.05 10.10 10.25 10.45 10.26 10.32 10.40 10.68 10.20 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 4.54 –36.96 655.63 790.50 665.56 518.37 –22.71 586.23 624.44 788.90 463.05 629.10 –368.58 –560.34 –394.89 –461.99 3,147.13 3,091.90 1,594.35 change storage Monthly –3,139.42 –2,392.75 –2,169.74 –1,702.41 –1,208.04 –2,322.24 –3,765.06 –3,910.41 –1,859.35 reservoir (acre-feet) - 0.06 0.03 0.14 0.07 0.23 0.00 0.05 0.04 0.09 0.21 0.04 0.21 0.05 0.01 0.15 0.05 0.02 0.03 0.06 0.00 0.04 0.01 0.00 0.06 0.04 0.18 0.08 0.01 (feet) Monthly tion rate precipita - 0.58 0.44 0.20 0.05 0.01 0.00 0.00 0.09 0.19 0.31 0.54 0.63 0.64 0.43 0.18 0.04 0.00 0.01 0.03 0.18 0.30 0.48 0.70 0.68 0.60 0.40 0.20 0.07 (feet) Monthly tion rate evapora - 471 431 413 420 430 441 448 451 443 456 510 522 505 476 461 460 460 463 472 481 497 503 478 434 377 336 325 334 Res area ervoir (acres) surface 19 93 –5 –9 294 312 154 –36 –69 –78 190 300 242 144 –34 –80 137 319 360 –91 –138 –140 –697 –105 –201 –194 (–) –1,685 –1,895 Monthly recharge/ discharge (acre-feet) groundwater - 0 4 8 0 3 0 5 30 12 56 29 97 22 16 42 95 20 23 68 24 14 26 19 26 17 59 27 110 tion feet) (acre- Monthly precipita - 5 0 1 1 3 84 23 41 83 83 17 12 88 65 25 271 188 139 273 327 325 202 149 240 333 293 225 136 tion feet) (acre- Monthly evapora - Res feet) ervoir (acre- 11,671 20,379 17,986 17,949 18,605 19,395 20,061 20,579 20,210 19,650 22,797 25,889 25,494 23,324 21,622 21,160 21,165 21,142 21,728 22,353 23,141 24,736 23,528 21,206 17,440 13,530 12,134 12,763 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 38 13 617 625 394 765 644 882 tion Irriga 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 36 41 85 39 outflows 291 381 174 237 464 210 (acre-feet) AVWTP Monthly pumped - 745 149 154 154 139 918 922 253 144 154 159 148 3,211 3,441 2,154 1,220 1,864 6,672 9,808 4,721 3,874 2,664 1,476 2,001 3,324 3,199 3,503 2,099 flow Monthly Dam out Red Fleet (acre-feet) 916 889 762 783 681 559 736 986 823 720 926 825 710 676 651 706 1,490 1,450 8,470 4,020 2,590 1,460 1,270 1,060 3,920 2,630 1,990 11,640 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,596.46 5,590.86 5,590.77 5,592.35 5,594.21 5,595.74 5,596.91 5,596.08 5,594.8 5,601.72 5,607.96 5,607.19 5,602.82 5,599.21 5,598.2 5,598.21 5,598.16 5,599.44 5,600.78 5,602.44 5,605.69 5,603.24 5,598.3 5,589.52 5,579.05 5,573.44 5,574.88 5,576.79 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year August-10 September-10 October-10 November-10 December-10 January-11 February-11 March-11 April-11 May-11 June-11 July-11 August-11 September-11 October-11 November-11 December-11 January-12 February-12 March-12 April-12 May-12 June-12 July-12 August-12 September-12 October-12 November-12 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, 20 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

- σ 8.74 9.18 7.87 8.70 5.60 9.21 5.71 0.24 2.87 6.00 9.86 0.52 6.46 8.64 7.30 7.39 6.40 11.37 14.30 73.52 17.12 33.16 10.15 42.83 76.24 31.01 21.33 19.21 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ 11.20 11.29 11.13 10.18 10.20 10.07 10.51 10.69 10.20 10.42 10.49 10.13 10.24 10.09 10.17 10.50 10.34 10.19 10.54 10.74 10.44 10.47 10.17 10.12 10.09 10.07 10.16 10.60 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un 619.27 625.48 404.79 488.27 249.67 355.03 737.44 738.48 603.83 552.11 618.91 586.44 926.99 875.66 729.49 590.99 723.43 –733.13 2,454.14 1,191.53 1,091.32 1,005.38 change storage Monthly –2,011.08 –2,787.08 –3,645.70 –2,143.72 –3,555.18 –1,282.73 reservoir (acre-feet) - 0.06 0.08 0.02 0.05 0.10 0.07 0.00 0.07 0.04 0.24 0.12 0.03 0.14 0.04 0.01 0.08 0.06 0.01 0.00 0.05 0.31 0.24 0.01 0.04 0.04 0.03 0.00 0.13 (feet) Monthly tion rate precipita - 0.01 0.00 0.00 0.13 0.22 0.54 0.82 0.85 0.65 0.41 0.18 0.05 0.00 0.00 0.06 0.16 0.29 0.49 0.71 0.83 0.61 0.44 0.24 0.05 0.02 0.01 0.07 0.20 (feet) Monthly tion rate evapora - 344 353 361 368 375 391 399 359 307 268 268 280 293 304 313 323 332 346 341 290 239 246 269 285 300 313 324 334 Res area ervoir (acres) surface 2 5 91 –86 –90 –78 –83 –54 153 294 –88 –56 –28 –59 –94 406 710 297 –64 –86 –72 –73 –60 –112 –134 –721 –204 –189 (–) Monthly recharge/ discharge (acre-feet) groundwater - 8 0 9 4 3 1 1 8 0 22 29 20 38 25 25 14 64 33 41 13 25 19 15 74 59 10 13 44 tion feet) (acre- Monthly precipita - 5 0 0 0 0 5 4 47 83 50 14 17 53 97 64 15 23 66 110 210 327 305 200 169 240 240 146 108 tion feet) (acre- Monthly evapora - 8,112 9,161 8,428 8,783 9,520 6,830 7,757 8,848 9,853 Res feet) ervoir (acre- 11,414 13,811 11,668 11,458 13,382 14,008 14,412 14,901 15,150 17,605 15,593 12,806 10,258 10,862 12,033 12,620 10,729 12,049 12,773 storage —, no data] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - 773 881 138 235 441 tion Irriga 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 0 0 0 45 45 68 outflows 108 357 359 204 283 329 218 (acre-feet) AVWTP Monthly pumped - 111 119 154 154 139 154 512 883 478 123 123 149 837 885 103 154 154 139 154 3,205 3,249 3,406 2,959 1,034 3,001 3,364 3,481 2,146 flow Monthly Dam out Red Fleet (acre-feet) 670 661 458 586 780 720 629 762 805 823 686 617 702 936 807 680 839 5,480 1,870 1,870 1,710 4,530 2,430 1,520 1,300 1,610 1,850 1,050 Creek inflow Monthly Big Brush (acre-feet) (feet) 5,578.62 5,580.42 5,581.56 5,582.91 5,583.59 5,589.93 5,584.78 5,576.92 5,565.09 5,562.32 5,563.64 5,566.29 5,568.83 5,570.83 5,572.63 5,574.57 5,576.36 5,579.86 5,573.43 5,561.31 5,555.97 5,559.74 5,563.88 5,567.45 5,570.37 5,572.77 5,574.62 5,576.82 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year December-12 January-13 February-13 March-13 April-13 May-13 June-13 July-13 August-13 September-13 October-13 November-13 December-13 January-14 February-14 March-14 April-14 May-14 June-14 July-14 August-14 September-14 October-14 November-14 December-14 January-15 February-15 March-15 Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, Assessment of Groundwater Interaction with Red Fleet Reservoir 21

- σ 8.66 9.87 3.28 7.47 — 26.61 22.48 37.44 13.41 27.74 Monthly recharge/ (acre-feet) certainty, 2 certainty, groundwater discharge un

- σ — 10.31 10.16 10.29 10.61 10.44 10.46 10.44 10.30 10.13 Monthly (percent) recharge/ certainty, 2 certainty, groundwater discharge un — 650.69 592.70 –183.01 –522.09 5,771.73 3,058.43 change storage Monthly –1,908.53 –2,846.40 –1,687.59 reservoir (acre-feet) - — 0.03 0.29 0.03 0.06 0.04 0.12 0.06 0.08 0.05 (feet) Monthly tion rate precipita - — 0.29 0.39 0.78 0.71 0.66 0.47 0.26 0.06 0.00 (feet) Monthly tion rate evapora - — 337 367 461 448 417 385 366 370 379 Res area ervoir (acres) surface 97 32 –84 212 359 128 266 –74 –259 (–) –39,900 Monthly recharge/ discharge (acre-feet) groundwater - 9 12 26 15 46 22 29 19 105 tion feet) (acre- 11,500 Monthly precipita - 0 98 94 21 142 358 317 275 179 tion feet) (acre- 51,700 Monthly evapora - — Res feet) ervoir (acre- 12,590 18,362 21,420 19,512 16,665 14,978 14,455 15,106 15,699 storage —, no data] 0 0 0 0 0 0 0 - 81 150 tion Irriga 21,300 0 0 0 0 22 outflows 203 239 296 166 (acre-feet) 21,200 AVWTP Monthly pumped - 149 154 3,511 1,688 1,521 2,945 3,150 2,200 1,088 flow 993,000 Monthly Dam out Red Fleet (acre-feet) 795 903 823 654 1,510 7,630 6,330 2,190 1,530 Creek inflow Monthly 1,050,000 Big Brush (acre-feet) — (feet) 5,576.27 5,591.77 5,598.77 5,594.48 5,587.57 5,583.12 5,581.68 5,583.47 5,585.06 altitude Reservoir Reservoir data, evaporation, and calculated recharge and discharge from Red Fleet Reservoir, Utah, 1980–2015.—Continued Reservoir data, evaporation, and calculated recharge discharge from Red Fleet Reservoir,

Month/year April-15 May-15 June-15 July-15 August-15 September-15 October-15 November-15 December-15 Total Table 1. Table Plant; σ, sigma (standard deviation); ­ Treatment Water Valley Ashley [AVWTP, 22 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

Meteorological Data solar-radiation data from the NRCS SCAN Split Mountain weather station from January 27, 2010, to December 31, 2015, Meteorological data utilized in this study have been were used for comparison to investigate spatial meteorological collected at the Vernal Airport weather station (fig. 1) in variability; during this period the average daily air temperature Vernal, Utah, since the filling of Red Fleet Reservoir in 1980. ranged from –25 to 28 °C. Daily solar radiation ranged from The Vernal Airport weather station is approximately 10 mi 31 to 860 calories per cm2/d. Cross-plotted average daily southwest of the reservoir at an elevation of 5,270 feet (ft) temperature data for the two sites between January 27, 2010, above sea level. Beginning in 2010, data from a Soil Climate and December 31, 2015, yielded a correlation coefficient of Analysis Network (SCAN) Split Mountain weather station 0.97. Cross-plotting the average daily solar-radiation data operated by the Natural Resources Conservation Service for the two sites for the same period yielded a correlation (NRCS) also were utilized. The NRCS SCAN Split Mountain coefficient of 0.92. On average, daily solar-radiation values weather station is approximately 13 mi south of the reservoir recorded at Split Mountain were about 50 calories per cm2/d (fig. 1) at an elevation of 4,844 ft above sea level. Data greater than at Vernal Airport. This is likely the result of from both weather stations have been used for evaluating numerous types of variability associated with solar-radiation evaporation and precipitation, which are required for measurements including individual sensor performance, calculating monthly groundwater recharge/discharge from Red latitudinal variation, and sensor orientation (level and free Fleet Reservoir. Parameters measured include air temperature, from shadow). wind speed, precipitation, relative humidity, and incoming Monthly precipitation totals recorded at the solar radiation. The solar-radiation and temperature data were Vernal Airport weather station from May 1980 through used for calculating evaporation using the McGuinness and December 2015 were used to estimate precipitation at Red Bordne (1972) version of the Jensen-Haise method. Fleet Reservoir; the monthly precipitation ranged from 0 to From May 1, 1980, to December 31, 2015, daily average about 0.37 ft (4.4 inches [in.]; table 1) and averaged about air temperature ranged from –29 to 28 degrees Celsius (°C) at 0.07 ft (0.8 in.). Average annual precipitation during the the Vernal Airport. The coldest temperatures during the year 36-year period from 1980 through 2015 was 9.3 in. (fig. 4). typically were in December and January, when minimum air The years when annual precipitation was greater than temperatures occasionally were below –35 °C. The warmest 1 standard deviation (1σ) or 11.4 in. were 1981, 1983, 1986, temperatures were typically in July, when maximum air 1997, 2010, and 2013, which is indicative of wetter than temperatures occasionally approached 40 °C. Daily average normal conditions near Red Fleet Reservoir. The years when solar radiation ranged from 39 to 790 calories per square annual precipitation was less than 1σ or 7.1 in. were 1988, centimeter per day (cm2/d). The minimum daily averages are 1989, 1991, 2001, 2002, 2007, and 2012, which is indicative typically in December and January, and the maximum daily of drier than normal conditions near Red Fleet Reservoir. averages are typically in June and July. Temperature and

14 EPLANATION Vernal Airport Natural Resources Conservation 12 Service (NRCS) Split Mountain

10

8

6

4 Annual precipitation, in inches

2

0 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2015 ear

Figure 4. Annual precipitation at Vernal Airport and Natural Resources Conservation Service Split Mountain weather stations, Utah, 1980–2015. Assessment of Groundwater Interaction with Red Fleet Reservoir 23

Water-Level Data land surface. The bottom 20 ft of RF2 is screened in the upper part of the Frontier Sandstone. Water levels in RF2 were about Water levels in four wells were recorded with Onset® 15–30 ft lower than the stage observed in Red Fleet Reservoir, Hobo water level data loggers from mid-August 2016 through which indicates a downward groundwater-flow gradient in the September 2017 (fig. 5). The Red Fleet Reservoir stage Frontier Sandstone aquifer west of the reservoir during the recorded by UWCD is plotted on figure 5 with reference to period of record. Water levels in well RF2 remained relatively water-level altitudes observed in nearby wells. A separate stable throughout the period of record with a slight increase data logger was installed 10 ft below land surface and about from 5,578 ft in August 2016 to 5,580 ft in September 2017. 40 ft above the average water level inside monitoring well Well RF1 is on the west side of the reservoir near the RF1 to record barometric pressure at the site for the same inflow arm about 800 ft west of the state park boat ramp and period (fig. 2). Barometric pressure data from this logger were about 550 ft from the nearest shore to the north. Water levels used to make water-level corrections because of barometric observed in well RF1 remained relatively stable throughout fluctuations over the period of record. Regular electric-tape the period of record with a slight increase in water level from measurements were taken at each of the four wells to facilitate 5,639 ft in August 2016 to 5,640 ft in September 2017. Well corrections to water levels recorded by the loggers. RF1 was drilled and cased in September 2016 to a depth of The Red Fleet Reservoir stage observed between 100 ft below land surface; the bottom 20 ft of RF1 is screened August 2016 and September 2017 fluctuated between in the Nugget Sandstone aquifer. The water levels in RF1 were about 5,585 ft to about 5,605 ft with low stage during the about 35–50 ft higher than the stage observed in Red Fleet late summer, and with the reservoir slowly filling through Reservoir, indicating that the Nugget Sandstone aquifer was the winter and reaching high stage in the late spring/early discharging water to Red Fleet Reservoir during the observed summer following spring runoff. Water levels observed in period of record. well DH-109 follow the same trend as the altitude of the Water levels observed in well DH-111 were about stage in Red Fleet Reservoir (fig. 5). Well DH-109 is on the 70–85 ft higher than the stage observed in Red Fleet Reservoir west side of the reservoir near the eastern tip of a peninsula over the same period. Well DH-111 is on the east side of the formed by the Frontier Sandstone that extends about 1,100 ft reservoir near Donkey Flats Road and was drilled by the BOR into the reservoir and was drilled by the BOR during the during the geologic investigations for the Red Fleet Dam geologic investigations for the Red Fleet Dam site in the site in the 1960s (fig. 2); DH-111 was drilled to a depth of 1960s; DH-109 was drilled to a depth of 201 ft below land 95 ft below land surface and is open to the Nugget Sandstone surface and is open to the Frontier Sandstone and the Morrison aquifer (Thompson, 1969). The water levels observed in Formation (Thompson, 1969). The water level observed in DH-111 were relatively stable with the exception of a water- DH-109 was consistently about 3 ft lower than the reservoir level increase in February 2017. This increase in water level stage, indicating that the reservoir was likely recharging the coincided with significant ponding from a mid-elevation Frontier Sandstone during the period of record. snowmelt around the well at that time. Given the shallow Well RF2 is on the west side of the reservoir near the depth to water (approximately 32 ft below land surface), the south end about 1,200 ft west of the nearest shore; RF2 was increase in water level was likely the result of local recharge. drilled and cased in September 2016 to a depth of 265 ft below

5,690

5,680

5,670

5,660

5,650

5,640

5,630 EPLANATION Wells 5,620 DH-111 Red Fleet Reservoir RF1 5,610 DH-109 RF2 5,600

5,590

Water-level altitude, in feet above sea level Water-level 5,580 5,570 07/19/2016 10/17/2016 01/15/2017 04/15/2017 07/14/2017 10/12/2017 Date (month/day/year)

Figure 5. Water-level altitude in selected wells and Red Fleet Reservoir stage, Uintah County, Utah, 2016–17. 24 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

Well DH-121, which was drilled by the BOR during Groundwater Movement the geologic investigations for the Red Fleet Dam site in the 1960s, is on the eastern peninsula that separates the Based on water-level measurements in six wells Cottonwood Wash arm of Red Fleet Reservoir from the main and one spring, altitudes of the potentiometric surface in body and wash (fig. 2). This well was drilled to a depth of September 2017 near Red Fleet Reservoir in the Nugget and 130 ft below land surface and in September 2016, the water Frontier Sandstones ranged from 5,578.13 to 5,726.00 ft. The level was 49 ft below land surface. The well is open to reservoir altitude during this same period was about 5,590 ft. the Morrison Formation and Dakota Sandstone. Given the The lines on figure 6 show the estimated potentiometric similar geographic conditions at DH-121, it is likely that the contours (lines of equal groundwater-level altitude) for the hydrologic responses in the well are similar to those observed Nugget and Frontier Sandstone aquifers. Groundwater- in DH-109. Well DH-121 was not instrumented with a water- flow gradients observed in September 2017 in the Nugget level recorder because of the difficulty of access. Sandstone aquifer indicate that groundwater was discharging Cottonwood Spring, located approximately 0.25 mi to Red Fleet Reservoir from the aquifer from the east and northwest of the Donkey Flats Road crossing of Cottonwood west banks of the reservoir. An upward vertical groundwater Wash, is a small spring that discharges in the channel of gradient also was observed in the Nugget Sandstone aquifer as Cottonwood Wash. The spring discharges at an elevation of the altitude of the water level in the Red Fleet State Park well, 5,726 ft above sea level and is near the geologic contact of the which has an open bottom at a depth of 510 ft below land Nugget Sandstone and the Carmel Formation. surface, was 5,645.76 ft compared to 5,640.45 ft in well RF1; well RF1 is 270 ft away and is screened to a depth of 99 ft below land surface (fig. 6).

10928 1092 1092 10925

Cottonwood Wash 403

DONKEY FLATS ROAD 5,720

CottonwoodSpr 5,700

U.S. HIGHWAY 191 5,680

5,660 Big Brush Creek

5,600 5,640 DH-111 5,620 5,620 5,640

RF1 RFSPPump

4035

OLD DONKEY FLATS ROAD Red Fleet Reservoir DH-121

EPLANATION 5,580 Potentiometric contour (dashed)— Big Brush Creek Frontier Sandstone DH-109 5,640 Potentiometric contour— Red Fleet Dam

Nugget Sandstone 5,585 RF2 5,580 Monitoring location

ase modified from U.S. Geological Survey and other 0 0.5 1 MIE Federal and state digital data, 1:22,000 scale Universal Transverse Mercator proection one 12 Central 0 0.5 1 KIMETER Meridian –111 orth American atum of 192

Figure 6. Potentiometric contours of the Nugget and Frontier Sandstone aquifers in September 2017, Red Fleet Reservoir, Utah. Assessment of Groundwater Interaction with Red Fleet Reservoir 25

Groundwater-flow gradients observed in September 2017 is 0.20 (20 percent) for E, which is based on differences in the Frontier Sandstone aquifer indicate that the reservoir between alternative methods for estimating evaporation at Red was recharging the aquifer on the west bank near Red Fleet Fleet Reservoir and other areas (Heilweil and Susong, 2007; Dam. The difference in groundwater altitude in well RF2 and Rosenberry and others, 2007). the stage of Red Fleet Reservoir in September 2017 indicates a The monthly amount of precipitation falling on the shallow gradient between the reservoir and the aquifer (fig. 6). reservoir is calculated by multiplying the total monthly precipitation recorded by the Vernal Airport weather station by the average reservoir surface area for that month (based Estimates of Groundwater Recharge and on reservoir water-level altitude to area relations for the Discharge from Red Fleet Reservoir reservoir; John Hunting, Uintah Water Conservancy District, written commun., 2016). The precipitation term in equation 1, Recharge from and discharge to Red Fleet Reservoir is however, does not account for precipitation runoff to the calculated as the residual with the following water-budget reservoir. Summer monsoon precipitation events occasionally equation (modified from Heilweil and others, 2005): produce runoff that reaches Red Fleet Reservoir, primarily through the Cottonwood Wash drainage. The volume of runoff RI= − O − O + P ±∆ SE − (1) sw sw pump produced by these events is negligible in comparison to the total reservoir water budget. where Monthly water-budget values for Red Fleet Reservoir R is recharge (acre-ft), are shown in table 1. Values are monthly totals, except for reservoir altitude and storage, which are shown for the last day Isw is surface-water inflow (acre-ft), of each month. Osw is surface-water outflow (acre-ft),

Opump is pumped outflow (acre-ft), P is the amount of precipitation falling directly Changes in Reservoir Storage on the reservoir (acre-ft), ΔS is the change in surface-water storage Changes in reservoir storage were calculated from daily (acre-ft), and reservoir water-level altitudes reported by the BOR using E is evaporation (acre-ft). altitude to volume relations (John Hunting, Uintah Water Conservancy District, written commun., 2016). Since Red The following equation was developed to evaluate the Fleet Reservoir began filling in May 1980, surface-water uncertainty for each monthly recharge estimate: storage increased to a maximum of about 26,000 acre-ft in June 1983. Between 1983 and 2015 surface-water storage  CU= ∑∑( Ci/ C ii)∗ U (2) in the reservoir seasonally fluctuated from about 15,000  to 26,000 acre-ft during average to above-average annual precipitation years, but dropped to about 7,000 acre-ft during where periods of below-average annual precipitation (table 1). CU is the composite uncertainty fraction (2 standard deviation, 2σ),

|Ci| is the absolute value of each component of the Reservoir Evaporation water budget (acre-ft), The McGuinness and Bordne (1972) version of the Σ|Ci| is the sum of absolute values of all the water- budget components (acre-ft), and Jensen-Haise method was selected for calculating evaporation from Red Fleet Reservoir and is based on the relation: Ui is the uncertainty fraction (2σ) for each individual water-budget component. = − PET{((0.01 Tas) 0.37)( Q ) 0.000673} 2.54 (3) The estimated uncertainty fraction is 0.10 (10 percent) for Isw, Osw, and Opump because these flows are recorded using USGS streamgaging methods, engineered control devices, where and calibrated inline flow meters. The estimated uncertainty PET is potential evaporation, in centimeters per fraction is 0.10 (10 percent) for ΔS because changes in day, surface-water storage are based only on approximate reservoir Ta is air temperature, in degrees Fahrenheit, and water-level altitude/volume relations rather than direct Qs is solar radiation, in calories per square measurements. The estimated uncertainty fraction for P is 0.20 centimeter per day. (20 percent) because it is an indirect measurement taken on the basis of nearby meteorology station data approximately The units for PET can be converted to feet per day by 10 mi from the study area. The estimated uncertainty fraction multiplying by 0.0328. 26 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

Monthly evaporation rates were calculated with weighted importance of evaporation losses, which have the equation 3 using air temperature and solar radiation from the highest uncertainty. nearby weather stations (fig. 1). These estimated evaporation Annual inflow, dam releases, pumped outflow, rates ranged from 0.00 to 0.85 foot per month from May 1980 evaporation, and groundwater recharge/discharge to and through December 2015 (table 1). Multiplying the estimated from Red Fleet Reservoir from 1980 through 2015 are evaporation rates by the average reservoir surface area yields shown on figure 3. During this period, total inflow was about monthly evaporation losses that ranged from about 0 to 1,050,000 acre-ft, with annual inflow ranging from about 380 acre-ft between May 1980 and December 2015. 12,000 acre-ft in 2002 to 49,000 acre-ft in 1998. From 1980 through 2015, total dam releases were about 993,000 acre-ft, with annual dam releases ranging from about 15,000 acre-ft Estimates of Groundwater Recharge and in 2013 to about 51,000 acre-ft in 1983. Total pumped Discharge at Red Fleet Reservoir outflow from 1980 through 2015 was about 42,000 acre-ft, with annual pumped outflow ranging from 0 acre-ft before Monthly estimates of precipitation (P), evaporation (E), 1986 to about 3,400 acre-ft in 2007. Total evaporation from inflow (I ), outflows (O and O ), and changes in surface- sw sw pump 1980 through 2015 was about 52,000 acre-ft, with annual water storage (ΔS) were used in equation 1 to calculate evaporation ranging from about 830 acre-ft in 1980 to about recharge and discharge to and from the Nugget and Frontier 1,770 acre-ft in 2007. Annual groundwater recharge was Sandstone aquifers beneath Red Fleet Reservoir. Monthly greatest in 2007 at about 4,000 acre-ft following a period from recharge (plus, +) and discharge (minus, –) from May 1980 early 2001 through early 2005 when the reservoir volume was through December 2015 ranged from about –2,800 to substantially decreased. Annual groundwater discharge was 2,200 acre-ft (fig. 7), with 2σ composite uncertainties ranging greatest in 1997 at about 4,900 acre-ft, and total groundwater from about 10 to 12 percent of the estimate (table 1). Higher recharge/discharge to Red Fleet Reservoir from 1980 through composite uncertainties in the summer reflect the larger, 2015 was about 40,000 acre-ft, with a 2σ uncertainty of 11,000 acre-ft (fig. 7; table 1).

5,620 3,000

5,600 2,000

5,580 1,000

5,560 0 Reservoir altitude, in feet

5,540 −1,000 Groundwater flux, in acre-feet

EPLANATION Reservoir stage 5,520 Groundwater flux −2,000 Aquifer discharge Aquifer recharge

5,500 −3,000 05/01/1980 05/01/1985 05/01/1990 05/01/1995 05/01/2000 05/01/2005 05/01/2010 05/01/2015 Date (month/day/year)

Figure 7. Reservoir stage and calculated groundwater recharge/discharge at Red Fleet Reservoir, Utah, 1980–2015. Assessment of Groundwater Interaction with Red Fleet Reservoir 27

Big Brush Creek Seepage Assessment Upstream The measured value at the upstream site was supported by of Red Fleet Reservoir a value computed from the stage-discharge rating model in use at the USGS streamgage. The model was previously A seepage study was completed on November 17, 2017, developed by calibrating stage to periodic streamflow on Big Brush Creek under baseflow conditions to quantify measurements. Discharge measurements were taken with a groundwater gains or losses between the Big Brush Creek SonTek FlowTracker2 handheld Acoustic Doppler Velocimeter streamgage (USGS 09261700) and the inflow to Red Fleet using standard USGS methods (Turnipseed and Sauer, Reservoir (fig. 8). Big Brush Creek is fed primarily by Brush 2010). Percent statistical uncertainty values calculated by Creek Spring approximately 4 mi upstream of the USGS the FlowTracker2 ADV software are used by the USGS as streamgage. The reservoir inflow site, about 1 mi downstream, standard practice for estimating discharge error because of was chosen to be as close as possible to Red Fleet Reservoir channel conditions and measurement instrumentation. For the without compromising measurement quality because of slack full methodology of this calculation see the section “Discharge water. There are no known surface-water inflows, turnouts, or Uncertainty Calculations Using a SonTek FlowTracker” in return points throughout the reach. SonTek (2009). Mean discharge measured at each location and Two discharge measurements were taken at the uncertainty values are shown on figure 9. downstream inflow site and one at the upstream gaged site.

10928 1092

Note: Figure shows Red Fleet Reservoir at full pool. Measurements were taken when reservoir stage was lower than the altitude of the downstream measurement site.

403530 U.S. HIGHWAY 191

i us C

USGS 09261700 Downstream Big Brush Creek measurement site

R Rsoi

4035

OLD DONKEY FLATS ROAD

ase modified from U.S. Geological Survey and other 0 0.25 0.5 MIE Federal and state digital data, 1:11,400 scale Universal Transverse Mercator proection one 12 Central 0 0.25 0.5 KIMETER Meridian –111 orth American atum of 192

Figure 8. Locations of seepage measurements taken on November 17, 2017, on Big Brush Creek upstream of Red Fleet Reservoir, Utah. 28 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

15.0

USGS 09261700 BIG BRUSH CRK ABV RED FLEET RES, NR VERNAL, UT 14.5 20.0

14.0 t n e m

10.0 e r

13.5 u a s e m o f

13.0 o d i r e P Discharge, cubic feet per second 5.0 00:00 04:00 08:00 12:00 16:00 20:00 00:00 12.5 Nov 15 Nov 15 Nov 15 Nov 15 Nov 15 Nov 15 Nov 16 2017 2017 2017 2017 2017 2017 2017 Mean discharge, in cubic feet per second ---- Provisional Data Subject to Revision ---- Median daily statistic (37 years) Measured discharge 12.0 Discharge Upstream Downstream Figure 10. Recorded discharge at the U.S. Geological Survey Big Figure 9. Measured discharge and uncertainty at two stations Brush Creek streamgage 09261700 during the November 17, 2017, on Big Brush Creek upstream of Red Fleet Reservoir, Utah. seepage assessment above Red Fleet Reservoir, Utah.

The measurements spanned a period of relatively Water-level data were collected at the pumping well (RFSP) steady flow conditions based on the continuous water-stage and at monitoring well RF1 for the duration of the test and record obtained from the streamgage (fig. 10). The increase during a 30-day recovery period so that transmissivity and or decrease between measurement sites represents the net storage coefficient values of the Nugget Sandstone aquifer seepage interchange between groundwater and surface water. could be estimated (fig. 11). The measurements show an increase in discharge between Pumping well RFSP is an 8.375-inch-diameter well the upstream and downstream sites of about 0.68 cubic completed in an 8.375-inch-diameter borehole. The drillers foot per second (ft3/s) or 4.8 percent of the gage streamflow log reports that the well only penetrates the Nugget Sandstone (fig. 10). Calculated seepage over the reach is subject to aquifer to a total depth of 510 ft below land surface. The well inherent measurement uncertainty, but is supported by trends is not screened or perforated and is only open to the aquifer in sampled radon concentration observed throughout the at the base of the well casing. The aquifer is assumed to be stream reach. The increase in flow observed under baseflow unconfined. The static water level before pumping began was conditions indicates a considerable annual groundwater 73.05 ft below land surface. discharge from the Nugget Sandstone aquifer to the Observation well RF1 is a 2-inch-diameter well stream reach. completed in a 6-inch-diameter borehole; it was drilled to a depth of 99 ft below land surface and only penetrates the Nugget Sandstone aquifer. The well is screened in the Nugget Evaluation of Aquifer Properties in the Sandstone aquifer from 79 to 99 ft below land surface and is 270 ft northeast of the RFSP pumping well. The static water Nugget Sandstone Aquifer near Red level before pumping began was 53.48 ft below land surface. Fleet Reservoir Aquifer Test Description and Analysis Regionally, the Nugget Sandstone aquifer is utilized as a good-quality groundwater source for domestic use. To The aquifer test commenced when well RFSP began better understand how groundwater flows through the Nugget pumping at 10:35 a.m. on March 9, 2017, and continued for Sandstone aquifer near Red Fleet Reservoir, a constant- 8 days until 10:35 a.m., March 17, 2017. Discharge from the discharge test was completed on the Red Fleet State Park pumped well ranged from 16.5 to 10.4 gal/min during the test drinking-water supply well (RFSP). This test was used to (fig. 12). Discharge water was routed away from the test site evaluate aquifer properties in the Nugget Sandstone aquifer through a 2-inch discharge line to a drainage approximately near Red Fleet Reservoir to compare to published values in 700 ft to the southeast (fig. 11). Once pumping had ceased, the region. The RFSP well was pumped at an average rate water levels were allowed to recover for 30 days. During the of 11 gallons per minute (gal/min) from March 9, 2017, to test and recovery period, water levels in wells RF1 and RFSP March 17, 2017, as part of an 8-day constant-discharge test. were monitored at 5-minute intervals. Evaluation of Aquifer Properties in the Nugget Sandstone Aquifer near Red Fleet Reservoir 29

109240 109230 109220

403510 R Rsoi

RF1 (Monitoring well) 270 feet

RFSP (Pumping well) Discharge pipe

4035

ase modified from U.S. Geological Survey and other 0 0.05 0.1 MIE Federal and state digital data, 1:2,00 scale Universal Transverse Mercator proection one 12 Central Meridian –111 orth American atum of 192 0 0.05 0.1 KIMETER

Figure 11. Locations of wells and discharge pipe used during the March 2017 Nugget Sandstone aquifer test at Red Fleet Reservoir, Utah. The Red Fleet State Park well is identified as a “pumping well” and RF1 is identified as a “monitoring well.”

An Excel spreadsheet program (SeriesSEE) was used The sum of the transformed data and the superimposed to analyze the data (Halford and others, 2012). A water-level Theis solution created the simulated water level observed on model was constructed to simulate water-level fluctuations figure 12. The resulting superimposed Theis solution from observed in well RF1 using data from barometric pressure, a this water-level model yielded a simulated transmissivity of nearby reference well (RF2) that was unaffected by pumping, 660 square feet per day (ft2/d) with a storage coefficient of and a superimposed Theis solution. A series of moving 0.13 for the Nugget Sandstone aquifer near the RFSP well. average transforms were applied to the barometric pressure The transmissivity and storage coefficient values fall within and reference-well data to analyze water-level fluctuations the range of known values for the Nugget Sandstone in with variable frequencies (fig. 13). the region. 30 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

0.4 18

EPLANATION 16 0.3 Difference (measured/simulated) Simulated Theis drawdown solution 14 Pumping well discharge 0.2 Measured water-level change 12 Simulated water-level change

0.1 10

8 0.0

6

Change in water level, feet −0.1 4 Pumping-well discharge, in gallons per minute −0.2 2

−0.3 0 02/26/2017 03/03/2017 03/08/2017 03/13/2017 03/18/2017 03/23/2017 05:50:00 05:50:00 05:50:00 05:50:00 05:50:00 05:50:00 Date, month/day/year Time

Figure 12. Measured change in water level from observation well RF1 near Red Fleet Reservoir resulting from pumping at the Red Fleet State Park well, and simulated change in water level from a Theis aquifer-response solution, March 2017, Red Fleet Reservoir, Utah. Evaluation of Aquifer Properties in the Nugget Sandstone Aquifer near Red Fleet Reservoir 31

100

100

Calcium (Ca

- ) 80 80 EPLANATION

2+ Nugget Sandstone aquifer ) + Magnesium (Mg 60 Red Fleet 60 ) + Chloride (Cl 2- Vernal area 4 Frontier Sandstone aquifer 40 40 Red Fleet Reservoir—inflow arm Sulfate (SO 2+ )

20 20

0 0

0 0

20 0 0 0 2 100 100 - ) 3

Sodium (Na 0 0 40 20 2 4 80 80

) 2+ + ) + Potassium (K 60 Sulfate (SO 0 0 40 4 6 60 60 ) + Bicarbonate (HCO 2- 3

4 2- 80 0 0 60 ) 6 8 Magnesium40 (Mg 40 + )

Carbonate (CO 100 80 0 0 8 0 20 1 20

100 0 0 1 0 0 100 80 60 40 20 0 0 20 40 60 80 100 Calcium (Ca2+) Chloride (Cl-)

Figure 13. Relative major-ion concentrations for selected wells near Red Fleet Reservoir, Utah. 32 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

Evaluation of Groundwater Water-chemistry samples were collected from 2-inch monitoring wells using a Grundfos RediFlo-2 or Geotech SS Geochemical Characteristics in the Geosub sample pump, and production wells were sampled utilizing installed submersible pumps. Before the water- Nugget and Frontier Sandstones chemistry sample collection from monitoring wells, water was purged from each well until a minimum of three casing Water samples were collected from four sites near and volumes were removed and field parameters had stabilized. in Red Fleet Reservoir, including two monitoring wells, After purging each well, water was pumped into samples a culinary well, and surface water from the reservoir. The bottles and filtered as necessary. water samples were analyzed for major ions, nutrients, Samples for major ions and trace ions were filtered and selected trace metals to characterize general chemistry with 0.45-micron disposable filters and collected in clean and patterns of water quality for a limited area near and polyethylene bottles according to procedures described by in Red Fleet Reservoir. Water samples also were analyzed Wilde and Radtke (1998); samples for cation analysis were for several environmental tracers including the radioactive preserved with 7.7-normal nitric acid. Tritium samples isotope of hydrogen (tritium, 3H), dissolved noble gases, were collected in 500-milliliter (ml) polyethylene bottles chlorofluorocarbons, and sulfur hexafluoride. These with polyseal caps without head space. The CFC and SF environmental tracers were used to investigate potential 6 samples were collected in 250-ml and 1-liter (L) glass bottles, groundwater recharge areas and groundwater ages to provide respectively, according to procedures described at the USGS an understanding of the groundwater interaction that occurs at Reston Groundwater Dating Laboratory (https://water.usgs. Red Fleet Reservoir. gov/lab/). Noble gases were collected with diffusion sampler Field parameters were measured to provide an on-site methods described by Sheldon (2002) and Gardner and characterization of surface-water and groundwater quality. Solomon (2009), and with copper-tube methods described by Field water-quality parameters included water temperature, Stute and Schlosser (2000). specific conductance, pH, dissolved oxygen, and total Inorganic and organic chemical analyses (major ions, dissolved-gas (TDG) pressure. Total dissolved-gas pressure trace ions, and dissolved organic carbon) were analyzed by the is the combination of the partial pressures of all the dissolved USGS at the National Water Quality Laboratory in Denver, gas in water. Colorado. The CFCs and SF6 were analyzed by the USGS at the Chlorofluorocarbon Laboratory in Reston, Virginia. Data Collection Methods Tritium and noble gases were analyzed by the University of Utah Dissolved Gas Laboratory using quadrupole and Field parameters were measured with a multi-parameter sector-field mass spectrometers; tritium concentrations sonde placed in the screened interval at the bottom of each were determined using the in-growth method (Clarke and 2-inch monitoring well, and in the reservoir at water depths others, 1976). of approximately 3 ft. The multi-parameter sonde was too large to enter the 1-inch access port on the Red Fleet State Park drinking-water well. Consequently, field measurements Data Interpretation Methods from this well were made on-site with a flow-through chamber connected to a discharge spigot near the well head before the Noble Gases drinking water holding tank. Dissolved heavy noble-gas samples (neon-20, 20Ne; Laboratory water-quality analyses of surface water from argon-40, 40Ar; krypton-84 84Kr; and xenon-129, 129Xe) were Red Fleet Reservoir and groundwater from the Nugget and used to determine noble-gas recharge temperatures (NGTs, Frontier Sandstone aquifers included major and trace dissolved assumed to equal the temperature of groundwater recharge as 3 inorganic and organic constituents, H, and noble and it crosses the water table) as an indicator of recharge source industrial dissolved gases. The major inorganic ions included (mountain versus reservoir) and groundwater movement. calcium, magnesium, sodium, potassium, bicarbonate, Noble gases dissolved in groundwater primarily are of sulfate, chloride, and nitrate. Trace ions and nutrients atmospheric origin, with concentrations being a function of included fluoride, bromide, iron, manganese, arsenic, nitrite, gas solubility (with the possible addition of excess air from ammonia, and orthophosphate. Dissolved organic constituents dissolution of trapped bubbles) at the temperature, pressure, included dissolved organic carbon. Dissolved gases included and salinity conditions when recharge crosses the water table. chlorofluorocarbons (trichlorofluoromethane, CFC-11; Variation in the solubility of individual noble gases is such dichlorodifluoromethane, CFC-12; and 1,1,2-trichloro-1,2,2- that measured concentrations of multiple noble gases can be trifluoroethane, CFC-113), sulfur hexafluoride (SF ), and 6 used to fit unique models of recharge conditions. Because noble gases (helium, He; neon, Ne; argon, Ar; krypton, Kr; noble gases are geochemically inert, groundwater NGTs and xenon, Xe). are preserved along the length of a groundwater flow path. Evaluation of Groundwater Geochemical Characteristics in the Nugget and Frontier Sandstones 33

A complete review of noble gases as groundwater tracers is in water. During the 1950s and 1960s, large amounts of 3H found in Stute and Schlosser (2000). were released into the atmosphere and introduced into the For this study, the noble-gas concentrations were hydrologic cycle by above-ground thermonuclear weapons interpreted using the closed-system equilibration (CE) model testing. As a result, 3H concentrations in precipitation in the (Aeschbach-Hertig and others, 2000; Kipfer and others, northern hemisphere during 1963–64 peaked at three orders of 2002). In addition to recharge temperature, the CE model also magnitude above natural concentrations (Michel, 1989). 3 3 calculates excess air as the dimensionless ratio of the total Concentrations of H and Hetrit can be used to determine volume of trapped (moist) air at the pressure and temperature the apparent age of groundwater that is less than about of the free atmosphere to the volume of water (A) and a 60 years old. These ages are referred to as “apparent” as the fractionation factor (F) accounting for partial dissolution calculation assumes plug flow along a single flow path (for of trapped air bubbles. For samples collected in areas of example, piston flow) and can differ from the true mean age high topographic gradient, the recharge altitude (a proxy of the sample if it contains a mixture of water of different for barometric pressure) is an unknown parameter. Because ages. Mixtures of modern (post-mid-1950s recharge) and recharge temperature (Tr) and recharge altitude are correlated, pre-modern (pre-mid-1950s recharge) water typically have 3 3 a range of NGTs (assumed to equal Tr) was calculated for apparent H/ Hetrit ages that represent the age of the young each sample with the most likely NGT determined by the fraction of the sample because dilution with pre-modern water 3 3 intersection of calculated NGT with the temperature lapse will leave the ratio of H to Hetrit virtually unchanged. Further rate, a method described by Manning and Solomon (2003) and details of this groundwater dating method are presented in Manning (2011). The range of possible NGTs was based on Solomon and Cook (2000). the minimum recharge altitude, typically that of the sample Although 3H in modern precipitation was not measured site and the maximum possible recharge altitude, which was during this study, recharge after 2012 is assumed to contain estimated to be 10,000 ft for all samples based on the elevation 6–11 tritium units (TU) as indicated by empirical relationships of high-altitude plateaus and lakes in the Uinta Mountains derived from measured 3H across a range of latitude and where recharge is most likely to occur. Temperature lapse longitude (Michel, 1989). In a sample of pre-modern rate and change in temperature as a function of altitude were groundwater, 3H would have decayed from background determined at points along south to north transects starting “prebomb” concentrations of about 8 TU to less than 0.3 TU, at the study area and based on 30-year mean annual air which is approaching the analytical detection limit. Samples temperature (PRISM Climate Group, 2012) and the National collected during this study having concentrations of 0.4 TU Elevation Dataset (U.S. Geological Survey, 2017). A water- or less and accounting for a typical analytical uncertainty table lapse rate was estimated based on general observations of 0.1 TU, were interpreted to contain no modern water. 3 3 of a +3 °C difference between air and water-table temperatures Apparent H/ Hetrit ages were computed for samples that had (Manning and Solomon, 2003). The recharge parameters concentrations of more than 0.4 TU. (NGT, A, and F) were evaluated across the range of recharge In addition to 3He derived from 3H decay, groundwater altitudes with a standard Newton inversion technique to also accumulates dissolved helium because it is produced from minimize the error-weighted misfit (χ2) between measured and the radioactive decay of naturally occurring uranium- and modeled dissolved-gas concentrations (Aeschbach-Hertig and thorium-series elements in aquifer solids (crustal He) and from others, 2000; Manning and Solomon, 2003). An χ2 probability the upward advection and (or) diffusion of primordial helium threshold of 3.84, based on four measured gases and three from the mantle (mantle He). Crustal- and mantle-sourced He recharge parameters (P greater than 0.05), was used to define are collectively referred to as “terrigenic He” (Heterr; Solomon, good model fits for NGT, A, and F. Because of noble-gas 2000). Crustal- and mantle-sourced He are distinguishable by measurement precision, uncertainty in NGTs is generally their relative abundance of 3He and 4He (helium-4) isotopes,

0.5–1.5 °C (Manning and Solomon, 2003; Manning, 2009; and because Heterr concentrations generally increase with Masbruch and others, 2012). increasing residence time. Dissolved terrigenic helium-4 4 ( Heterr) concentrations have been used as a semiquantitative tool for dating groundwater with ages from 1,000 to more than Tritium and Helium Isotopes 1,000,000 years (Mazor and Bosch, 1992; Solomon, 2000). Tritium and helium isotopes were used in this study No attempts were made to accurately date groundwater in this study using 4He because crustal He production rates are to evaluate the age of groundwater and reservoir samples. terr terr Tritium is a radioactive isotope of hydrogen with a half-life highly variable and substantial additional data would have of 12.32 years (Lucas and Unterweger, 2000) that decays been required to constrain these rates within the study area. 4 to tritiogenic helium-3 (3He ). Tritium is present in water Even without precise knowledge of local He production rates, trit 4 as part of the water molecule, whereas its decay product He concentrations in excess of atmospheric solubility are 3 useful as qualitative measures of groundwater age. ( Hetrit) is a component of the total helium budget dissolved 34 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

Lumped Parameter Modeling tracer pairs and identify anomalous tracer concentrations which could indicate tracer contamination or biodegradation. Categorical Tritium Age Relative merit of the optimized mean age and age distribution Measured tritium values can be used to categorically are assessed by the number of fitted tracers, the sum of chi- 2 define the age of groundwater by correcting the estimated squared statistic (χ ), tracer cross-plots, objective judgment annual tritium concentration of local precipitation for regarding distribution model parameters, and tracer selection the radioactive decay of tritium, which has a half-life of based on the conceptual hydrogeology and other nearby 12.32 years (Lucas and Unterweger, 2000). For this study, the samples. categories were defined as pre-modern (pre-1953 recharge) with measured 3H concentrations less than 0.4 TU, modern Water-Quality Results (post-1953 recharge) with 3H concentrations of greater than 3.5 TU, and a mixture of pre-modern and modern water Major Ions, Nutrients, and Trace Metals with 3H concentrations between these two values. The categorical age is useful in assigning a generalized age and Water-quality results from the Nugget and the Frontier in identification of outlier tracers because3 H is the least Sandstones indicated two distinct chemical water types. susceptible to contamination or other in situ alterations. The Nugget Sandstone aquifer near Red Fleet Reservoir can be characterized as calcium-magnesium-bicarbonate Groundwater Age water with dissolved-solids concentrations that ranged from 135 to 240 milligrams per liter (mg/L; fig. 13; table 2). An estimated mean age and age distribution, describing Concentrations of trace metals sampled including arsenic, the relative contribution of various flow paths, were selenium, and uranium, were all low with ranges of 0.05– determined for each sample using a modified version of 0.07 micrograms per liter (μg/L) for arsenic, 0.46–2.11 μg/L TracerLPM (Jurgens and others, 2012; Bryant Jurgens, for selenium, and 0.71–8.35 μg/L for uranium. All of the U.S. Geological Survey, written commun., 2013) and a local concentrations for trace metals and nutrients in Nugget hydrogeologic conceptualization. The lumped parameter Sandstone wells sampled near Red Fleet Reservoir were modeling (LPM) approach assumes steady-state groundwater below the Environmental Protection Agency (EPA) maximum flow and conservative tracer behavior (with the exception of contaminant levels. Overall water quality of the wells sampled radioactive decay). The selected conceptual age distribution in the Nugget Sandstone indicates that the aquifer is a good for a given sample is mathematically convoluted with the source of drinking water. Geochemical results for two wells measured atmospheric tracer concentrations (input functions) west of the study area (fig. 1), but within the Vernal, Utah, to calculate tracer concentrations for any given mean age. region are included in figure 13 and table 2 for comparison The mean age and age-distribution parameters are optimized to known Nugget Sandstone aquifer geochemistry outside to match the measured and simulated tracer concentrations. the influence of a nearby reservoir. Water from Vernal area Selection of the most suitable LPM is based on multiple wells screened in the Nugget Sandstone was very similar to lines of evidence including conceptual hydrogeology, tracer water sampled from wells near Red Fleet Reservoir, indicating concentrations, and LPM results, and is an iterative process. that the reservoir has limited interaction with the Nugget Geologic cross sections and lithologic well logs were used Sandstone aquifer. to develop a conceptual model of the hydrogeology. The A sample from well RF2 was used to characterize and conceptual hydrogeology provides context and physical evaluate water quality in the Frontier Sandstone aquifer constraints on the selection of a suitable distribution (see near Red Fleet Reservoir (fig. 13; table 2). This sample was “Jurgens and others, 2012” for conceptual flow-path characterized as a calcium-magnesium-sulfate water with a diagrams). For this study, the dispersion model (DM) with dissolved-solids concentration of 2,150 mg/L. The trace metals a small dispersion parameter of 0.001 (inverse of the Peclet sampled included arsenic at 9.42 μg/L, selenium at 15.2 μg/L, number; Jurgens and others, 2012) was used in lieu of the and uranium at 1.33 μg/L; all were below EPA maximum piston-flow model, which does not account for hydrodynamic contaminant levels. The nitrate and nitrite concentrations were dispersion along flow paths in real groundwater-flow well below EPA maximum contaminant levels for drinking systems. Use of a DM brings the conceptualized flow system water of 10 and 1 mg/L, respectively. The elevated selenium represented by the LPM more in line with known physical concentration in well RF2 was likely derived from the processes. Measured tracer concentrations are used to overlying Mancos Shale, a known reservoir of selenium in the select tracers for LPM modeling and refine age-distribution region. Overall water quality in well RF2, which represents selection. Tracer cross-plots are a graphical representation the upper part of the Frontier Sandstone aquifer, was poor of the convolution of two tracer input functions for a given because of the high dissolved-solids concentration. age distribution and are used to check consistency between Evaluation of Groundwater Geochemical Characteristics in the Nugget and Frontier Sandstones 35 - 4.66 1.58 2.81 4.26 1.64 Cl) 14.3 0.021 (mg/L as Chloride phate) <0.004 <0.004 <0.004 <0.004 <0.004 (mg/L as P) (orthophos Phosphorous ) 4 4.34 3.12 12.9 24.4 43.8 SO Sulfate 1,240 (mg/L as N) — 0.31 <0.01 <0.01 <0.01 <0.01 (mg/L as ) ammonia Nitrogen, 3 96.4 142 120 127 248 120 CaCO N) — — (mg/L as 0.002 Alkalinity nitrite <0.001 <0.001 <0.001 (mg/L as Nitrogen, - K) 1.67 1.13 0.92 2.63 5.39 1.09 sium Potas N) 0.94 0.50 0.83 (mg/L as <0.01 <0.04 <0.04 nitrate) (mg/L as (nitrite + Nitrogen 4.26 1.79 2.79 3.35 4.91 Na) 95.7 U) Sodium 1.14 0.71 1.58 8.35 1.33 1.03 (mg/L as (μg/L as Uranium - - 16.7 12.8 12.7 30.2 76.9 10.2 Mg) sium 2.11 1.05 0.46 0.69 0.51 Se) nium 15.2 Magne Sele (mg/L as (μg/L as - 0.47 9.95 1.07 35.1 28.8 31.3 56.0 38.1 Ca) Mn) <0.20 <0.20 nese 391 321 (μg/L as Manga Calcium (mg/L as - 9.6 13.1 <5 <4 235 Fe) Iron 168 135 139 240 172 2,150 (μg/L as 10,000 solids (mg/L) solved Total dis Total 0.07 0.05 0.20 9.42 0.97 As) <0.10 (μg/L as Arsenic — — 9.1 8.9 0.0 7.2 (mg/L) oxygen ) Dissolved 2 9.83 8.85 7.41 5.69 SiO 10.1 40.1 Silica (mg/L as 8.1 8.3 8.0 7.8 6.9 8.2 pH units) (standard — — 97.1 Cl:Br 105.3 126.5 164.0 - 302 228 247 466 270 2,810 tance — — Br) (μS/cm) 0.048 0.015 0.113 0.010 conduc Specific (mg/L as Bromide , Red Fleet State Park; —, no data available; <, less than] - 11.0 11.4 11.0 (°C) 10.9 10.9 15.0 ture 0.17 0.11 0.14 0.19 0.58 0.10 as F) (mg/L Tempera Fluoride Date Date : USGS, U.S. Geological Survey; °C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; Cl:Br, chloride- Cl:Br, liter; per milligrams mg/L, Celsius; degrees 25 at centimeter per microsiemens μS/cm, Celsius; degrees °C, Survey; Geological USGS, U.S. : 9/17/2013 9/17/2013 10/13/2016 10/13/2016 10/24/2014 10/12/2016 10/13/2016 10/13/2016 10/13/2016 10/24/2014 10/12/2016 10/13/2016 Abbreviations . identifier USGS site identifier USGS site figure 2 figure 403451109260001 403508109263901 403506109264201 403254109352401 403215109354501 403418109260901 403451109260001 403508109263901 403506109264201 403254109352401 403215109354501 403418109260901 . Field measurements and major ions, selected trace elements, nutrient concentrations in groundwater surface water from s elected sites near Red Fleet

2. Site name Site name inflow arm inflow arm RF1 RFSP (D-3-21)20bac-1 (D-3-21)20ccc-1 RF2 Red Fleet Reservoir RF1 RFSP (D-3-21)20bac-1 (D-3-21)20ccc-1 RF2 RedFleet Reservoir Table Table Utah Reservoir, on sites are plotted [Sample to-bromide ratio; μg/L, micrograms per liter; RF1 and RF2 are wells; RFSP 36 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

Red Fleet Reservoir water sampled from the inflow arm cool NGTs of 0 and 2.36 °C for RFSP and RF1, respectively, was characterized as a calcium-sulfate-bicarbonate water and corresponding recharge elevations (table 3; fig. 14), with a dissolved-solids concentration of 172 mg/L (fig. 13; indicate that high-elevation snowmelt is the primary recharge table 2). The reservoir water did have higher concentrations source. The warmer NGT of 7.51 °C at RF2 indicates a larger of sulfate than surrounding Nugget Sandstone aquifer proportion of low-elevation recharge, with warmer recharge water, which was likely the result of dissolution of sulfate- temperatures, was being captured at the well. As shown by bearing minerals upstream of Red Fleet Reservoir in the Big hydraulic gradients, groundwater chemistry, and estimated Brush Creek drainage. The trace metals sampled included ages, the warmer low-elevation recharge was not likely to arsenic at 0.97 μg/L, selenium at 0.51 μg/L, and uranium at be recharge from the reservoir, but rather lower elevation 1.03 μg/L; all were below EPA maximum contaminant levels. mountain recharge. The nitrate and nitrite concentrations were well below EPA maximum contaminant levels for drinking water of 10 and 1 mg/L, respectively. 14 EPLANATION Calculated noble-gas Environmental Tracer Results 12 temperature-lapse rate RF1 RF2 Noble-Gas Analysis 10 RFSP Water-table lapse rate Air lapse rate Noble-gas samples were collected at three groundwater 8 wells with measured concentrations of Ne, Ar, Kr, and Xe 2 being well explained by the CE model (χ fits less than 0.5 6 for all samples) that indicated low amounts of excess air that was moderately fractionated (table 3; fig. 1). A full range of 4 possible NGTs were calculated for each site (fig. 14), with most likely NGTs determined by the intersection of water 2 table and air lapse rates with the modeled NGT lapse rate. Noble-gas recharge temperature, in degrees Celsius Air-temperature lapse rates were used for two sites (RF1 and 0 RFSP) because calculated NGTs did not intersect estimated 3,000 5,000 7,000 9,000 11,000 water-table temperatures. This indicates that the geothermal Recharge water table elevation, in feet above mean sea level gradient does not have a strong effect on water-table temperature in the recharge zone for these two sites, possibly Figure 14. Modeled noble-gas recharge temperature and as a result of relatively rapid recharge (see “Manning and elevation for groundwater sampled near Red Fleet Reservoir, Utah. Solomon, 2003” for further discussion of the relation between mean annual air temperature and recharge temperature). The

Table 3. Noble-gas model results from samples collected at Red Fleet Reservoir, Utah.

[R/Ra, ratio of helium-3 to helium-4 (He-4) measured in the sample to the atmosphere (Atmo,); ccSTP/g, cubic centimeters at standard temperature and pressure per gram of water; °C, degrees Celsius; atm, atmospheres; F, fractionation factor; ∆Ne, percent (%) difference between measured and modeled neon concentration; χ2, chi-squared model fit; RFSP, Red Fleet State Park; —, no data available; Ne, neon; Ar, argon; Kr, krypton; Xe, xenon; RF1 and RF2 are wells]

Atmo. Elevation R/Ra He-4 NGT Excess air F ∆Ne Gases Site pressure χ2 (feet) (unitless) (ccSTP/g) (°C) (ccSTP/g) (unitless) (%) modeled (atm) RFSP 3,300 1.01 4.60156E–08 0 0.02 — 0.66 0.0004 0.48 Ne, Ar, Kr, Xe RF1 2,850 1.02 5.82296E–06 2.36 0.03 0.71 0.59 –0.0004 0.17 Ne, Ar, Kr, Xe RF2 2,450 0.79 8.36451E–06 7.51 0.06 0.74 0.51 0.0012 0.36 Ne, Ar, Kr, Xe Evaluation of Groundwater Geochemical Characteristics in the Nugget and Frontier Sandstones 37

3 Age Tracers and Mean Age of the sample as underestimation of Hetrit resulted in an underestimation of the “true” 3H/He age. Estimated mean ages Measured 3H ranged from 0.2 to 7.9 TU with were considered more reliable in comparison to 3H/He ages corresponding categorical 3H ages that varied from modern to 3 because there was evidence of error in Hetrit calculations. 3 pre-modern, and calculated Hetrit values that ranged from 0 3 to 3 TU (table 4). Tracer cross-plots show Hetrit values were lower than expected, based on known atmospheric tracer 30 histories, even for a mixture of modern and pre-modern water 3 (fig. 15). Lower than expected Hetrit was possibly a result of error in the helium balance as indicated by calculated values 25 3 3 3 3 of initial H (sum of H and Hetrit). Initial H should be equal 3 to or greater than the background H of 8 TU from cosmogenic 20 production. Initial 3H less than 8 TU is one indication 3 that Hetrit is not entirely reliable and should be cautiously interpreted. Measured CFC concentrations were internally 15 inconsistent with disagreement between the CFCs (CFC-11, -12, -113) and historical record of measured atmospheric 10 concentrations, indicating contamination or degradation, making age determinations based on CFCs unreliable; thus, 5

CFC concentrations are not reported here. helium–3, in tritium units Tritiogenic Estimated mean ages, calculated based on 3H only and the selected age distributions, ranged from 25 to 73 years 0 (table 4). The exponential mixing model was most appropriate for the reservoir because it represents mixing of the full –5 range of flow-path ages. Samples from wells were best 0 2 4 6 8 represented by a DM, approximating a piston-flow model, Tritium, in tritium units as determined by the hydrogeology, well characteristics, and EPLANATION LPM results. A larger component of pre-modern water could Piston-flow model (PFM) Exponential mixing model (EMM) have been present in the samples, but was not captured by Binary mixing model (BMM) the estimated mean ages. Helium-4 was the only pre-modern Wells tracer collected, which was difficult to interpret quantitatively, RF1 RF2 limiting the ability to identify additional pre-modern water. RFSP Apparent 3H/He age was only defined for two samples (RF1 and RFSP) with respective ages of about 25 and 45 years. Figure 15. Age-tracer cross-plot of groundwater near Red Fleet The apparent 3H/He age represented the minimum possible Reservoir, Utah. age of the young component (modern fraction of a mixture)

Table 4. Age-tracer concentrations and estimated mean age and age distribution of groundwater near Red Fleet Reservoir, Utah.

3 3 3 [ID, identification; H, tritium; TU, tritium units; Hetrit, tritiogenic helium-3; H age, tritium age; Est, estimated; dist, distribution; RF Res, Red Fleet Reservoir; ±, plus or minus; —, no data available; EMM, exponential mixing model; RF1 and RF2 are wells; DM, dispersion model; RFSP, Red Fleet State Park]

Est. mean Sample 3H 3He 3H/3He age Station ID Sample date trit trit 3H age age Age dist. name (TU) (TU) (years) (years) 403451109260001 RF Res 11/14/2016 7.9 ± 0.35 — — Modern 25 ± 5.8 EMM 403418109260901 RF1 11/13/2016 1 ± 0.1 3.03 ± 0.8 24.7 Mixture 67 ± 0.2 DM 403508109263901 RF2 11/12/2016 1.6 ± 0.09 –0.05 ± 0.01 — Mixture 66 ± 0.1 DM 403506109264201 RFSP 10/13/2016 0.2 ± 0.03 1.78 ± 1.02 45 Pre-modern 73 ± 1.8 DM 38 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

Discussion From 1980 through 2015, Big Brush Creek discharged water at an average of 29,200 acre-feet per year to Red Fleet Multiple sources of evidence indicate that groundwater Reservoir with a total discharge of about 1,050,000 acre-feet in the Nugget Sandstone aquifer is not significantly recharged (acre-ft). Maximum and minimum annual discharge from by Red Fleet Reservoir. Modeling results with dissolved Big Brush Creek to Red Fleet Reservoir from 1980 through noble gases in sampled groundwater indicate that the source 2015 was 49,000 and 12,200 acre-ft, respectively, with the of groundwater recharge occurs at much lower temperatures minimum in 2002 and the maximum in 1998. Streamflow more common to high-altitude mountainous regions observed discharge from Red Fleet Reservoir is controlled by gates and north of the reservoir in the Uinta Mountains. A comparison jet valves at the base of Red Fleet Dam as well as a spillway of major-ion chemistry in sampled Nugget Sandstone aquifer on the east abutment. Total dam releases from 1980 through wells near the reservoir and wells several miles from the 2015 were about 993,000 acre-ft, with annual dam releases reservoir indicates similar characteristics in the aquifer during this period ranging from about 15,000 acre-ft in 2013 regionally that differ from the chemistry observed in Red to about 51,000 acre-ft in 1983. Total evaporation from Fleet Reservoir (table 2). Water levels observed in the Nugget 1980 through 2015 was about 52,000 acre-ft, with annual Sandstone near the reservoir also indicate that there is a strong evaporation during this period ranging from about 830 acre-ft flow gradient from the aquifer to the reservoir with observed in 1980 to about 1,770 acre-ft in 2007. The average annual water levels in nearby wells ranging from about 35 to 70 ft pumped volume of water from the Tyzack Pump Station at the higher than the maximum reservoir stage (fig. 5). Groundwater base of Red Fleet Dam during years when pumping occurred chemistry and groundwater-flow gradients indicate that there was about 1,400 acre-ft. The total volume of water pumped is limited evidence of groundwater recharging the Nugget from the Tyzack Pump Station from 1980 through 2015 was Sandstone aquifer immediately surrounding the reservoir, about 42,500 acre-ft. Total groundwater discharge to Red Fleet and groundwater discharge from the Nugget Sandstone to the Reservoir from 1980 through 2015 was about 40,000 acre-ft. reservoir is the dominant exchange. Conversely, groundwater Based on water-level measurements at six wells and one altitudes in the Frontier Sandstone were 15 to 30 ft lower than spring, altitudes of the groundwater in September 2017 near the reservoir, indicating that reservoir water is recharging the Red Fleet Reservoir in the Nugget and Frontier Sandstones Frontier Sandstone aquifer. ranged from 5,578 to 5,726 feet (ft). The reservoir altitude Trends observed in groundwater discharge volumes during this same period was about 5,590 ft. Groundwater- calculated in the Red Fleet Reservoir water budget indicate flow gradients observed in September 2017 in the Nugget that periods of greatest groundwater discharge occur Sandstone aquifer indicated that groundwater was discharging synonymously during late spring/early summer snowmelt to Red Fleet Reservoir from the east and west banks of the runoff and peaks at similar periods to peakflows observed reservoir. The water levels in the Frontier Sandstone aquifer in the Big Brush Creek discharge record (fig. 7). Results observed at well RF2 were about 15–30 ft lower than the stage from the seepage study done during baseflow conditions in observed in Red Fleet Reservoir, which indicates a downward November 2017 indicate that the reach of Big Brush Creek groundwater-flow gradient in the Frontier Sandstone west of between the USGS streamgage and the top of Red Fleet the reservoir from August 2016 through September 2017. Reservoir is a gaining reach. It is likely that some of the An aquifer test in the Nugget Sandstone aquifer was groundwater discharge calculated in the Red Fleet Reservoir completed utilizing the Red Fleet State Park well. This well water budget occurs as seepage to Big Brush Creek before it was pumped at an average rate of 11 gallons per minute enters the reservoir. from March 9, 2017, to March 17, 2017, as part of an 8-day constant-discharge test. Water-level data were collected at the pumping well and at observation well RF1 for the duration of the test and during a 30-day recovery period so that Summary transmissivity and storage coefficient values of the Nugget Sandstone aquifer could be estimated. Aquifer properties The objectives of this study were to present and interpret determined by a numerical model for the Nugget Sandstone (1) groundwater levels, reservoir altitude, meteorological aquifer near the pumping well yielded a transmissivity of data, and inflows/outflows to and from Red Fleet Reservoir 660 square feet per day with a storage coefficient of 0.13. from May 1980 through December 2015 in order to estimate Water samples were collected from four sites near and monthly groundwater recharge/discharge to and from in Red Fleet Reservoir: two monitoring wells, a culinary surrounding aquifers; (2) aquifer properties for the Nugget well, and surface water from the reservoir. The water samples Sandstone near Red Fleet Reservoir from a two-well aquifer were analyzed for major ions, nutrients, and selected trace test; and (3) groundwater and surface-water chemical data metals to characterize general chemistry and patterns of water to evaluate the origin of water in aquifers adjacent to Red quality for a limited area near and in Red Fleet Reservoir. Fleet Reservoir. References Cited 39

Water samples also were analyzed for several environmental Heilweil, V.M., and Susong, D.D., 2007, Assessment tracers including the radioactive isotope of hydrogen (tritium, of artificial recharge at Sand Hollow Reservoir, 3H), dissolved noble gases, chlorofluorocarbons, and sulfur Washington County, Utah, updated to conditions hexafluoride. The Nugget Sandstone aquifer near Red Fleet through 2006: U.S. Geological Survey Scientific Reservoir can be characterized as calcium-magnesium- Investigations Report 2007–5023, 14 p., bicarbonate water with dissolved-solids concentrations https://doi.org/10.3133/sir20075023. that range from 135 to 169 milligrams per liter. The Frontier Sandstone aquifer near Red Fleet Reservoir can be Heilweil, V.M., Susong, D.D., Gardner, P.M., and Watt, D.E., characterized as calcium-magnesium-sulfate water with a 2005, Pre- and post-reservoir ground-water conditions dissolved-solids concentration of 2,150 mg/L. Apparent 3H/He and assessment of artificial recharge at Sand Hollow, (helium) age was only defined for two samples (wells RF1 Washington County, Utah, 1995–2005: U.S. Geological and RFSP) with respective ages of about 25 and 45 years. The Survey Scientific Investigations Report 2005–5185, 74 p., apparent 3H/He age represents the minimum possible age of https://doi.org/10.3133/sir20055185. the young component (modern fraction of a mixture) of the Jurgens, B.C., Böhlke, J.K., and Eberts, S.M., 2012, sample as underestimation of tritiogenic helium-3 resulted TracerLPM (Version 1): An Excel workbook® for 3 in an underestimation of the “true” H/He age. Recharge interpreting groundwater age distributions from temperatures calculated from dissolved noble gases sampled environmental tracer data: U.S. Geological Survey at two wells in the Nugget Sandstone aquifer indicate that Techniques and Methods 4–F3, 60 p., accessed March 10, high-elevation snowmelt is the primary recharge source. 2017, at https://doi.org/10.3133/tm4F3. The warmer recharge temperature calculated from noble-gas samples from the Frontier Sandstone aquifer from well RF2 Kipfer, R., Aeschbach-Hertig, W., Peeters, F., and Stute, M., indicates a larger proportion of low-elevation recharge, which 2002, Noble gases in lakes and ground waters: Reviews in is consistent with the idea that the Frontier Sandstone aquifer Mineralogy and Geochemistry, v. 47, no. 1, p. 615–700, is recharged by the Red Fleet Reservoir. https://doi.org/10.2138/rmg.2002.47.14. Lucas, L.L., and Unterweger, M.P., 2000, Comprehensive review and critical evaluation of the half-life of References Cited tritium: Journal of Research of the National Institute of Standards and Technology, v. 105, no. 4, p. 541–549, Aeschbach-Hertig, W., Peeters, F., Beyerle, U., and Kipfer, R., https://doi.org/10.6028/jres.105.043. 2000, Paleotemperature reconstruction from noble gases Manning, A.H., 2009, Ground-water temperature, in ground water taking into account equilibrium with noble gas, and carbon isotope data from the Española trapped air: Nature, v. 405, no. 6790, p. 1040–1044, Basin, New Mexico: U.S. Geological Survey https://doi.org/10.1038/35016542. Scientific Investigations Report 2008–5200, 69 p., Clarke, W.B., Jenkins, W.J., and Top, Z., 1976, https://doi.org/10.3133/sir20085200. Determination of tritium by mass spectrometric 3 Manning, A.H., 2011, Mountain-block recharge, present measurements of He: The International Journal of and past, in the eastern Española Basin, New Mexico, Applied Radiation and Isotopes, v. 27, no. 9, p. 515–522, USA: Hydrogeology Journal, v. 19, no. 2, p. 379–397, https://doi.org/10.1016/0020-708X(76)90082-X. https://doi.org/10.1007/s10040-010-0696-8. Gardner, P., and Solomon, D.K., 2009, An advanced passive Manning, A.H., and Solomon, D.K., 2003, Using diffusion sampler for the determination of dissolved gas noble gases to investigate mountain-front recharge: concentrations: Water Resources Research, v. 45, no. 6, Journal of Hydrology, v. 275, no. 3–4, p. 194–207, https://doi.org/10.1029/2008WR007399. https://doi.org/10.1016/S0022-1694(03)00043-X. Halford, K., Garcia, C.A., Fenelon, J., and Mirus, B.B., Masbruch, M.D., Chapman, D.S., and Solomon, D.K., 2012, Advanced methods for modeling water-levels and 2012, Air, ground, and groundwater recharge estimating drawdowns with SeriesSEE, an Excel add-in temperatures in an alpine setting, Brighton Basin, (ver. 1.1, July 2016): U.S. Geological Survey Techniques Utah: Water Resources Research, v. 48, no. 10, 12 p., and Methods 4–F4, 28 p., https://doi.org/10.3133/tm4F4. https://doi.org/10.1029/2012WR012100. 40 Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah

Mazor, E., and Bosch, A., 1992, Helium as a semi-quantitative Solomon, D.K., and Cook, P.G., 2000, 3H and 3He, tool for groundwater dating in the range of 104 to 108 years, chap. 13 of Cook, P.G., and Herczeg, A.L., eds., in Consultants meeting on isotopes of noble gases as tracers Environmental tracers in subsurface hydrology: Boston, in environmental studies; Panel proceedings series, Vienna, Mass., Kluwer Academic Publishers, p. 397–424, Austria, May 29 to June 2, 1989: Vienna, International https://doi.org/10.1007/978-1-4615-4557-6_13. Atomic Energy Agency, p. 163–178. Sontek, YSI Incorporated, 2009, FlowTracker Handheld McGuinness, J.L., and Bordne, E.F., 1972, A comparison ADV Technical Manual Firmware Version 3.7, Software of lysimeter-derived potential evapotranspiration with Version 2.30: YSI Incorporated, 116 p. computed values—U.S. Department of Agriculture Technical Bulletin 1452: Washington, D.C., Agricultural Stute, M., and Schlosser, P., 2000, Atmospheric noble Research Service, 71 p., http://ageconsearch.umn.edu/ gases, chap. 11 of Cook, P.G., and Herczeg, A.L., eds., bitstream/171893/2/tb1452.pdf. Environmental tracers in subsurface hydrology: Boston, Mass., Kluwer Academic Publishers, p. 349–377, Michel, R.L., 1989, Tritium deposition in the continental https://doi.org/10.1007/978-1-4615-4557-6_11. United States, 1953–83: U.S. Geological Survey Water-Resources Investigations Report 89–4072, 46 p., Thompson, F., 1969, Feasibility geology report of the Tyzack https://doi.org/10.3133/wri894072. Dam and reservoir sites, Jensen Unit, Central Utah Project, Utah: U.S. Bureau of Reclamation Central Utah Project PRISM Climate Group, Oregon State University, website Report G-261. accessed July 11, 2012, at http://prism.oregonstate.edu. Turnipseed, D.P., and Sauer, V.B., 2010, Discharge Rosenberry, D.O., Winter, T.C., Buso, D.C., and Likens, G.E., measurements at gaging stations: U.S. Geological 2007, Comparison of 15 evaporation methods applied Survey Techniques and Methods book 3–A8, 87 p., to a small mountain lake in the northeastern USA: https://doi.org/10.3133/tm3A8. Journal of Hydrology, v. 340, no. 3–4, p. 149–166, https://doi.org/10.1016/j.jhydrol.2007.03.018. U.S. Geological Survey, 2017, The National Map— 3DEP products and services: The National Map, 3D Sheldon, A.L., 2002, Diffusion of radiogenic helium Elevation Program web page, accessed June 20, 2017, at in shallow ground water—Implications for crustal https://nationalmap.gov/3DEP/3dep_prodserv.html. degassing: Salt Lake City, Utah, University of Utah, Ph.D. Dissertation, 185 p. Wilde, F.D., and Radtke, D.B., 1998, National field manual for the collection of water-quality data, field measurements: Solomon, D.K., 2000, 4He in groundwater, chap. 14 of U.S. Geological Survey Techniques of Water-Resources Cook, P.G., and Herczeg, A.L., eds., Environmental Investigations, book 9, chap. A6, 233 p. tracers in subsurface hydrology: Boston, Mass., Kluwer Academic Publishers, p. 425–440, https://doi.org/10.1007/978-1-4615-4557-6_14. For more information concerning the research in this report, contact the Director, Utah Water Science Center U.S. Geological Survey 2329 West Orton Circle Salt Lake City, Utah 84119-2047 801-908-5000 https://ut.water.usgs.gov

Publishing support provided by the U.S. Geological Survey Science Publishing Network, Sacramento Publishing Service Center Marston and others—Groundwater and Surface-Water Resources near Red Fleet Reservoir, Uintah County, Utah—Scientific Investigations Report 2019–5101 ISSN 2328-0328 (online) https://doi.org/10.3133/sir20195101