Northeast Wyoming River Basin 2002 Water Plan Chapter 3

Northeast Wyoming River Basins Water Plan
Final Report

III Available Surface Water and Ground Water Determination

This chapter presents estimates of the availability of surface water to meet future water uses and also characterizes the potential for ground water development.

As with all chapters in this final plan report, explicit lists of references are not provided. Instead, all references to reports, maps, and personal communications are provided in the various Technical Memoranda prepared during the planning process. The reader is referred to the following technical memoranda for a more detailed description of each topic as well as the list of references:

Surface Water Hydrology
Spreadsheet Model Development and Calibration
Available Surface Water Determination
Available Ground Water Determination

A. Surface Water

The determination of available surface water is broken down into seven components discussed in the following sections:

Compilation of Historic Streamflow Records
Study Period Selection
Data Extension
Estimating Natural Flow at Ungaged Model Nodes
Determining Streamflows during Wet, Normal, and Dry years
Spreadsheet Model Development and Calibration
Determination of Available Surface Water

It should be noted that the results described herein pertain to physical availability over and above existing uses, which is to be distinguished from legal or permitted availability. Physical availability is the important first step in assessing the viability of any future project. Lack of physical availability of water for a project is an obvious fatal flaw for any water development.

Historic Streamflow Records

Available records of streamflow in the Northeast Wyoming River Basins planning area have been compiled for this study.

The location of the various streamflow gaging stations are plotted in relation to the significant storage reservoirs and the irrigated lands mapped for the Basin Plan (Figures III-1 through III-2). The streamflow gages that are relatively free from the influence of depletions or storage regulations are characterized as natural flow stations. Where reasonably possible, those gages that are impacted by upstream irrigation depletions were adjusted to remove these effects. The list of streamflow gages inventoried for this study is provided in Table III-1.

Prior to 1970, there were only 13 streamflow gages in operation in the planning area. Beginning in the 1970s and 1980s, with the installation of an additional 18 streamflow gages, records for a total of 31 streamflow stations became available.

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Study Period

It is important in any water availability evaluation to select a study period that is long enough to include a variety of hydrologic conditions including an extended period of dry years as well as wet years and normal years. At the same time, it is also important not to select a study period so long that many streamflows must be synthesized to fill-in missing data.

It is desirable in evaluating long-term hydrologic conditions to utilize streamflow records for a station that has a long period of continuous records and that reflects natural (virgin) flow, unaffected by upstream depletions or storage regulation. Unfortunately, no such streamflow gaging station exists in, or in near vicinity to, the Northeast Wyoming River Basins. The USGS has, however, maintained streamflow stations on Beaver Creek near Newcastle (#06394000) and the Cheyenne River at Edgemont, South Dakota (#06395000) since the mid 1940s (Table III-1). The Beaver Creek gage was discontinued in 1998. The records for these gages are impacted by upstream irrigation depletions and storage, primarily in the form of stock ponds. The change in carryover storage from year to year is however expected to be relatively minor and the amount of irrigation depletion in relation to the total streamflow is not expected to vary greatly from year to year. The records for these stations although non-natural can therefore be used as a reasonable representation of annual hydrologic conditions. The USGS has also maintained a streamflow station on the Belle Fourche River below Moorcroft (#06426500) since 1944 with some gaps in the record in the 1970s and 1980s (Table III-1). Similar to stations on Beaver Creek and the Cheyenne River, the streamflow at this gage is impacted by upstream irrigation depletion and stock pond storage. The record for this station can however be used to represent hydrologic conditions in the Belle Fourche drainage. The USBR maintains records of computed inflows into Keyhole Reservoir downstream from the Moorcroft gage (#06426500). This information was utilized to develop a regression relationship between streamflows at the upstream Moorcroft gage and inflows to Keyhole Reservoir to fill-in the missing records in the 1970s and 1980s. The relationship is shown below:

        Q_06426500 = 0.671* Q_{Keyhole Inflow}  . 386.2
        
        Where:  Q_06426500 is monthly streamflow at Gage #06426500 in acre-feet and
                 Q_{Keyhole Inflow} is computed inflow to Keyhole Reservoir from USBR 
                in acre-feet.

Table III-1
Streamflow Stations in the Northeast Wyoming River Basins

Basin Station
Number Station Name Natural Flow Period of Record in Water Years
** Note

Cheyenne 06364700 Antelope Creek Near Teckla, WY NO 1978-1981

06365300 Dry Fork Cheyenne River Near Bill, WY NO 1977-1981, 1986-1987

0635900 Cheyenne River Near Dull Center, WY NO 1976-1981, 1986-1987

06375600 Little Thunder Chreek Near Hampshire, WY NO 1978-1981, 1988-1998

06376300 Black Thunder Creek Near Hampshire, WY NO 1973-1990

06378300 Lodgepole Creek Near Hampshire, WY NO 1978-1981

06379600 Box Creek Near Bill, WY YES 1956-1958

06386000 Lance Creek Near Riverview, WY NO 1948-1954, 1956-1983

06386500 Cheyenne River Near Spencer, WY NO 1949-1974

06392900 Beaver Creek at Mallo Camp, Near Four Corners, WY YES 1975-1982, 1991-current

06392950 Stockade Beaver Creek Near Newcastle, WY NO 1975-1982, 1991-current

06394000 Beaver Creek Near Newcastle, WY NO 1945-1998

06394500 Beaver Creek Near Burdock, SD NO 1905-1907, 1929-1932 Abt. 2 mi. into SD

06395000 Cheyenne River at Edgemont, SD NO 1903-1907, 1928-1933, 1947- Several Miles into SD; No winter records 1903-1906

Belle Fourche 06425720 Belle Fourche River Below Rattlesnake Creek, Near Piney, WY NO 1976-1983

06425750 Coal Creek Near Piney, WY YES 1981-1983

06425780 Belle Fourche River Above Dry Creek Near Piney, WY NO 1976-1983

06425900 Caballo Creek at Mouth Near Piney, WY, WY NO 1977-1983

06425950 Raven Creek Near Moorcroft, WY YES 1977-1983

06426000 Belle Fourche River Near Moorcroft, WY, WY NO 1923-1933

06426100 Stonepile Creek at Gillette, WY YES 1988-1992 No Winter records; Adjusted for diversions using Burlington Lake Ditch

06426400 Donkey Creek Near Moorcroft, WY NO 1977-1981

06426500 Belle Fourche River Below Moorcroft, WY NO 1943-1970, 1976-1983, 1986-1987, 1991-current

USBR Gage Inflow to Keyhole Reservoir NO USBR: 1952-current Adjusted for evaporation

USBR Gage Belle Fourche - Keyhole Reservoir Releases NO USBR: 1952-current

06427500 Belle Fourche River Below Keyhole Reservoir, WY NO 1951-1995

06428000 Belle Fourche River at Hulette, WY NO 1929-1933, 1938-1952

06428200 Belle Fourche River Near Alva, WY NO 1989-1998 No winter records

06428500 Belle Fourche River at Wyoming-South Dakota State Line NO 1947-current

06429500 Cold Springs Creek at Buckhorn, WY YES 1975-1982, 1991-current

06429900 Sand Creek at Ranch A Near Beulah, WY YES 1975-1976 Combined with Station 06429905

06429905 Sand Creek Near Ranch A Near Beulah, WY YES 1976-1983, 1991-current

06430500 Redwater Creek at Wyoming-South Dakota State Line, WY NO 1929-1931, 1936-1937, 1954- Adjusted for diversion using Murrey Ditch

Niobrara 06454000 Niobrara River at Wyoming-Nebraska State Line, WY NO 1956-1994

**Unless otherwise noted, records were obtained from the USGS

The coefficient of determination (R²) for this relationship is 0.87. The coefficient of determination is defined as the proportion of variation in the independent variable that can be explained by variation in the dependent variable. The higher the value of R2, the stronger the relationship between the two variables. A perfect relationship would have an R² equal to 1.0. Regression of hydrologic data resulting in R² greater than 0.7 is typically considered strong enough for data estimating.

The recorded and estimated streamflow records from the gages on Beaver Creek (#06394000), the Cheyenne River (#06395000), and the Belle Fourche River (#06426500) are selected as representative of the hydrologic conditions throughout the Northeast Wyoming River basins.

Figures III-3, III-4, and III-5 are Cumulative Surplus/Deficit plots for Beaver Creek, the Cheyenne River, and the Belle Fourche River respectively for the longest concurrent period of record (1947 to 1997 or 1999). A Cumulative Surplus/Deficit plot represents a running total of the annual deviations from the long-term mean annual streamflow. Downward sloping lines (left to right) represent periods of time during which annual streamflow is less than the long-term mean (dry periods). Conversely, upward sloping lines represent years, which are wetter than average (wet periods). As can be seen from these plots, the hydrologic conditions can vary considerably throughout the Northeast Wyoming River Basins in any given period of years. By way of example, the period 1964 to 1970 is generally a wet period on Beaver Creek. Whereas, on the Cheyenne River, this same period is generally average, and on the Belle Fourche River, 1964 to 1970 is generally a dry period. Some similarities do however exist throughout the study area. The periods 1959 to 1961, 1979 to 1985, and 1988 to 1990 are generally dry periods at all locations. The years 1962 and 1978 are also extreme wet years at all locations.

Based on an evaluation of the long-term hydrologic conditions at the three representative streamflow stations, together with the an understanding of the availability of historic streamflow records, the 30-year period 1970 through 1999 was selected as the study period for this Basin Plan. The average annual flow for the period 1970 to 1999 ranges from 9% drier than the long-term period on the Cheyenne River to 12% wetter than the long-term period on the Belle Fourche River. This period also contains extended periods of dry years at all locations including some of the driest years of record as well as periods of normal and wet hydrologic conditions.

A more detailed discussion and supporting documentation for the selection of the study period are provided in the "Surface Water Hydrology" technical memorandum.

Figure III-3
Cumulative Surplus/Deficit of Annual Historic Flows
Beaver Creek Near Newcastle, WY (Station 06394000)

Figure III-4
Cumulative Surplus/Deficit of Annual Historic Flows
Cheyenne River at Edgemont, SD (Station 06395000)

Figure III-5
Cumulative Surplus/Deficit of Annual Historic Flows
Belle Fourche River Below Moorcroft, WY (Station 06426500)

Data Extension

The spreadsheet modeling approach used for the Basin Plan utilizes model nodes located at historic streamflow gaging stations in order to take advantage of the historic records of streamflow at these locations. These records however contain many data gaps during the 1970 to 1999 study period. Monthly streamflows must therefore be estimated for those months, during the study period, with no recorded streamflow data.

The monthly record extension approach used in this study follows the procedure used by the USGS in recent studies. This mixed-station procedure uses the best base station from among all available base stations to fill in each month of missing data for a given gage. The base station producing the smallest standard error of prediction is used for each particular month. The technique used to estimate missing values was developed by Hirsch and is referred to as MOVE.1 (Maintenance of Variance Extension, Type 1). This technique offers the advantage over ordinary least-squares regression of preserving the variance of the unextended records. This procedure was carried out using a computer program developed by the USGS.

The USGS streamflow stations are divided into hydrologically similar groups with each group having at least one gage with sufficient data to develop relationships based on concurrent streamflow for the entire study period. The groupings also represent stations affected by similar reservoir operations. In particular, those stations below Keyhole Reservoir are grouped together because they all experience the same impacts from Keyhole operations. The monthly flow extension procedure is performed for each of these groupings of monthly streamflow data. There is a certain amount of overlap in hydrologic similarity among the various groupings. Some streamflow stations are therefore included in multiple groups.

As mentioned previously, regression of hydrologic data resulting in a coefficient of determination (R² greater than 0.7) is typically considered strong enough for data estimating. In some instances no significant correlation (R² less than 0.7) could be found using concurrent monthly streamflows between any base station and the short record station. Annual flow regression rather than monthly flow regression was performed in these instances to fill-in the missing streamflow data. In some cases, no significant correlation (R² less than 0.7) could be found using the annual flow regression either. Three of these stations were dropped from the study. Four other stations on Beaver Creek and the Niobrara River were retained and the study periods for modeling were adjusted to utilize historic records only. The monthly streamflows for the years of missing data were estimated by applying the average monthly distribution for the period of recorded streamflow to the estimated total annual flow.

The average monthly and annual streamflows during the study period are summarized in Table III-2 for the gaging stations selected for use in the water availability models. Supporting data and computation results for the data extension process is provided in the "Surface Water Hydrology" technical memorandum.

Table III-2
Summary of Average Monthly and Annual Flows (1970 to 1999 unless otherwise noted)
at Gaged Model Nodes

Basin Station
Number Station Name Natural
Flow Average Streamflow for 1970-1999 in Acre-Feet Note

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Annual

Cheyenne 06364700 Antelope Creek Near Teckla, WY NO 97 64 18 22 159 545 291 1,520 1,005 361 148 93 4,323

06365300 Dry Fork Cheyenne River Near Bill, WY NO 3 6 5 3 17 44 20 194 37 30 8 1 366

0635900 Cheyenne River Near Dull Center, WY NO 176 101 26 36 407 798 633 3,475 2,247 854 425 66 9,244

06375600 Little Thunder Chreek Near Hampshire, WY NO 3 4 5 5 48 86 11 824 131 135 100 2 1,354

06376300 Black Thunder Creek Near Hampshire, WY NO 307 16 0 51 272 846 308 1,788 671 549 405 498 5,710

06378300 Lodgepole Creek Near Hampshire, WY NO 1 2 1 1 2 45 33 223 91 32 34 1 464

06386000 Lance Creek Near Riverview, WY NO 133 111 83 333 870 1,205 902 5,594 2,717 2,993 2,078 694 17,713

06386500 Cheyenne River Near Spencer, WY NO 275 233 71 1,023 1,487 866 2,040 20,050 9,286 2,103 535 3,453 41,423

06392900 Beaver Creek at Mallo Camp, Near Four Corners, WY YES 112 102 100 97 98 127 138 136 144 131 120 112 1,415 Study Period: 1975-1982, 1992-1997

06392950 Stockade Beaver Creek Near Newcastle, WY NO 786 763 785 769 721 877 785 654 675 699 730 751 8,996 Study Period: 1975-1982, 1992-1997

06394000 Beaver Creek Near Newcastle, WY NO 876 804 796 881 2,381 5,716 2,353 3,250 2,339 1,106 797 497 21,796 Study Period: 1975-1982, 1992-1997

06395000 Cheyenne River at Edgemont, SD NO 1,910 1,416 684 800 3,106 8,847 4,275 14,156 10,524 4,720 3,269 1,700 55,407

Belle Fourche 06425720 Belle Fourche River Below Rattlesnake Creek, Near Piney, WY NO 6 6 12 24 79 212 66 685 236 101 149 20 1,596

06425780 Belle Fourche River Above Dry Creek Near Piney, WY NO 21 6 14 45 190 611 131 1,097 282 239 179 70 2,887

06425900 Caballo Creek at Mouth Near Piney, WY, WY NO 13 10 1 10 27 221 30 788 76 99 45 18 1,339

06425950 Raven Creek Near Moorcroft, WY YES 6 0 0 2 54 169 3 78 2 7 13 0 333

06426400 Donkey Creek Near Moorcroft, WY NO 34 18 33 20 37 1,707 145 2,309 104 17 5 4 4,434

06426500 Belle Fourche River Below Moorcroft, WY NO 682 203 149 420 1,761 4,664 2,268 5,169 2,134 997 515 281 19,243

USBR Gage Belle Fourche River - Total Keyhole Reservoir Discharge NO 114 320 0 1 0 881 784 2,149 2,402 4,821 4,526 761 16,759

06427500 Belle Fourche River Below Keyhole Reservoir, WY NO 257 260 103 104 96 1,015 760 2,194 2,362 4,833 4,600 833 17,417

06428200 Belle Fourche River Near Alva, WY NO 1,826 1,648 1,063 1,375 2,419 7,705 7,511 10,171 7,526 4,925 4,981 1,998 53,148

06428500 Belle Fourche River at Wyoming-South Dakota State Line NO 2,307 2,082 1,272 1,741 3,233 10,987 10,552 15,575 12,134 6,507 5,402 2,336 74,127

06429905 Sand Creek Near Ranch A Near Beulah, WY YES 1,312 1,307 1,285 1,237 1,092 1,231 1,288 1,881 1,776 1,499 1,480 1,334 16,722

06430500 Redwater Creek at Wyoming-South Dakota State Line, WY NO 2,108 2,077 2,043 2,006 1,928 2,240 2,367 3,697 3,135 2,190 2,245 2,119 28,155

Niobrara 06454000 Niobrara River at Wyoming-Nebraska State Line, WY NO 150 151 159 179 207 316 297 249 208 143 151 118 2,328 Study Period: 1970-1994

Natural Flow at Ungaged Model Nodes

The water availability models for this Plan have been developed identifying appropriate locations of model nodes in relation to the various surface water diversion points, return flow locations, and storage reservoirs. Model nodes are located, in large part, at historic streamflow gaging stations in order to take advantage of the historic records of streamflow at these locations. Additionally, it is necessary to locate model nodes at locations with no record of streamflow, to appropriately simulate water use in the various drainages. The locations of the ungaged model nodes are shown on Figure III-6.

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The following two methods were used to estimate natural flow at these locations:

Use the streamflow records from a nearby gaging station on the same stream, adjusting for depletions and storage regulation to estimate natural flow at the location of interest.
Use the recorded natural flow from a gaged stream with similar hydrologic characteristics, adjusting for the difference in drainage area at the location of interest.

The first method was used for Donkey Creek, southeast of Gillette in the Belle Fourche River basin. This method yielded the most reasonable estimates of natural flow for this location as evaluated during the calibration of the water availability models. The depletions (diversions minus return flows) used to make the adjustments to the downstream gage records are based on three representative hydrologic conditions (wet, normal, and dry years) and are taken from the water availability modeling work.

Natural flow for the majority of the ungaged model nodes was estimated using the second method, which relies on measured natural flow at selected streamflow gages in the Northeast Wyoming River Basins. The natural flow gage in nearest proximity and with the most similar hydrologic conditions was used to estimate natural flow at the ungaged locations. The original selections were further evaluated and, in some cases modified, as part of the calibration of the water availability models. In addition to average annual natural flow at the ungaged model nodes, it is necessary to generate sequential monthly flows at these sites for all years of the study period. This was accomplished by selecting a natural flow gaging station having similar hydrologic characteristics and multiplying the sequential monthly flows at the gaged location by the ratio of the ungaged average annual natural flow to the gaged average annual natural flow. The time distribution of monthly flows at the ungaged sites is, therefore, represented by the streamflow at similar gaged sites. The average monthly and annual streamflows for the study period, for the ungaged model nodes are summarized in Table III-3.

A more detailed discussion of the derivation of the streamflows at the ungaged model nodes is provided in the "Surface Water Hydrology" memorandum.

Table III-3
Summary of Average Monthly and Annual Flows
at Ungaged Natural Flow Nodes

Basin Station Name Estimated Average Streamflow for 1970-1999 in Acre-Feet

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Annual

Cheyenne Willow Creek at Mouth in Section 28, T38N, R72W 9 0 0 3 76 238 4 109 3 10 18 0 470

Woody Creek at Mouth in Section 5, T39N, R69W 1 0 0 0 10 31 0 14 0 1 2 0 59

Lake Creek at Mouth in Section 30, T40N, R68W 3 0 0 1 23 72 1 33 1 3 5 0 142

Sheep Creek at Mouth in Section 7, T40N, R67W 1 0 0 0 7 23 0 11 0 1 2 0 45

Wagonhound Creek at Mouth in Section 31, T41N, R67W 2 0 0 1 15 48 1 22 1 2 4 0 96

Snyder Creek at Mouth in Section 23, T40N, R64W 8 0 0 3 71 223 3 103 3 10 17 0 441

Boggy Creek at Mouth in Section 32, T40N, R63W 2 0 0 1 20 61 1 28 1 3 5 0 122

Sevenmile Creek at Mouth in Section 34, T40N, R63W 1 0 0 0 10 30 0 14 0 1 2 0 58

Mule Creek at Mouth in Section 6, T39N, R61W 4 0 0 1 31 96 1 44 1 4 7 0 189

Robbers' Roost Creek at Mouth in Section 23, T40N, R61W 5 0 0 2 43 136 2 63 2 6 10 0 269

Beaver Creek Just Below Mush Creek in Section 32, T44N, R62W 33 0 0 10 292 1,187 15 546 16 51 77 0 2,227¹

Oil Creek at Mouth in Section 26, T43N, R62W 346 0 0 61 3,958 6,405 377 2,930 87 275 2,425 0 16,864

Blacktail Creek at Mouth in Section 2, T41N, R61W 200 195 193 186 163 188 191 293 262 240 215 198 2,524

Dry Beaver Creek at Mouth in Section 4, T47N, R60W 107 99 97 92 95 111 133 136 141 130 118 107 1,366

Belle Fourche Dry Creek at Mouth in Section 29, T47N, R70W 2 0 0 1 14 43 1 20 1 2 3 0 87

Yellow Hammer Creek at Mouth in Section 10, T47N, R70W 1 0 0 0 5 16 0 7 0 1 1 0 31

Whitetail Creek at Mouth in Section 32, T48N, R69W 1 0 0 0 8 24 0 11 0 1 2 0 47

Four Horse Creek at Mouth in Section 11, T48N, R69W 8 0 0 3 73 228 4 105 3 10 17 0 451

Timber Creek at Mouth in Section 2, T48N, R69W 2 0 0 1 19 60 1 27 1 3 5 0 119

Buffalo Creek at Mouth in Section 14, T49N, R68W 11 0 0 3 93 290 4 133 4 12 22 0 572

Donkey Creek Just Upsteam of Gage in Sec. 30, T50N, R68W 0 0 0 413 1,135 3,278 1,555 4,005 946 0 0 0 11,332¹

Trail Creek at Mouth in Section 24, T50N, R68W 1 0 0 0 10 32 0 15 0 1 2 0 61

Dry Creek at Mouth in Section 24, T50N, R68W 2 0 0 1 14 45 1 21 1 2 3 0 90
Robinson Creek at Mouth in Section 18, T50N, R67W 1 0 0 0 4 14 0 6 0 1 1 0 27

Duck Creek at Mouth in Section 8, T50N, R67W 5 0 0 4 59 115 4 53 2 5 24 0 271

Miller Creek at Mouth in Section 9, T50N, R67W 58 0 0 41 672 1,314 44 604 18 57 271 0 3,079

Smoke Creek at Mouth in Section 9, T50N, R67W 1 0 0 1 17 34 1 16 0 1 7 0 78

Berger Creek at Mouth in Section 12, T50N, R67W 2 0 0 2 28 56 2 26 1 2 11 0 130
Lone Tree Creek at Mouth in Section 26, T51N, R67W 5 0 0 4 62 121 4 55 2 5 25 0 283

Wind Creek at Mouth in Section 13, T50N, R67W 133 0 0 93 1,539 3,008 101 1,382 41 129 620 0 7,046

Deer Creek at Mouth in Section 23, T51N, R67W 28 0 0 20 325 635 21 292 9 27 131 0 1,488

Eggie Creek at Mouth in Section 21, T51N, R66W 4 0 0 3 45 88 3 40 1 4 18 0 206

Mule Creek at Mouth in Section 15, T50N, R66W 17 0 0 12 197 385 13 177 5 17 79 0 902

Cottonwood Creek at Mouth in Section 35, T51N, R66W 5 0 0 3 52 102 3 47 1 4 21 0 238

Arch Creek at Mouth in Section 11, T51N, R66W 7 0 0 2 62 195 3 90 3 8 15 0 385

Inyan Kara Creek at Mouth in Section 25, T52N, R66W 1,154 1,142 1,122 1,083 1,028 1,311 1,128 1,750 1,553 1,319 1,310 1,165 15,065

Cabin Creek at Mouth in Section 14, T52N, R66W 5 0 0 2 47 148 2 68 2 6 11 0 291

Miller Creek at Mouth in Section 12, T52N, R66W 5 0 0 1 39 122 2 56 2 5 9 0 241

Lytle Creek at Mouth in Section 8, T53N, R65W 3 0 0 1 27 84 1 39 1 4 6 0 166

Whitetail Creek at Mouth in Section 14, T54N, R65W 83 82 81 78 69 77 81 118 112 94 93 84 1,052
Blacktail Creek at Mouth in Section 12, T54N, R65W 210 209 205 198 175 197 206 301 284 240 237 213 2,675

Beaver Creek at Mouth in Section 1, T55N, R64W 459 457 449 433 382 431 451 658 621 524 518 467 5,850

East Creek at Mouth in Section 32, T55N, R63W 48 48 47 45 40 45 47 68 65 55 54 49 611

Arnold Creek at Mouth in Section 28, T55N, R63W 22 22 22 21 18 21 22 32 30 25 25 23 283

Horse Creek at Mouth in Section 19, T56N, R61W 76 75 74 71 63 71 74 108 102 86 85 77 962

Pine Creek at Mouth in Section 33, T56N, R61W 172 171 168 162 143 161 169 247 233 197 194 175 2,192

Kilpatrick Creek at Mouth in Section 3, T55N, R61W 69 69 68 65 58 65 68 99 94 79 78 70 882

Kruger Creek at Mouth in Section 11, T55N, R61W 34 34 33 32 28 32 33 48 46 39 38 34 431

Oak Creek at Mouth in Section 20, T55N, R60W 216 215 211 203 179 202 212 309 292 247 243 219 2,748

South Redwater Creek Just Above Sand Creek in Section 31, T53N, R60W 565 563 553 533 470 530 555 810 765 646 637 575 7,202

Redwater Creek Just Above South Redwater Creek in Section 31, T53N, R60W 287 286 281 271 239 269 282 411 388 328 324 292 3,658
Note: 1. Monthly and Annual Flows are averaged from the Wet, Dry, and Normal Estimated Flows.

Streamflows During Wet, Dry, and Normal Years

The water availability models developed for this Basin Plan represent dry year, normal year, and wet year hydrologic conditions throughout the Northeast Wyoming River Basins. To this end, the annual streamflows for the study period developed through the surface water hydrology work are ranked and divided into these three hydrologic categories. Indicator gages are selected for this purpose, to represent hydrologic conditions for the entire geographic area of the Northeast Wyoming River Basins. The seven indicator gages are shown on Figure III-7.

click to enlarge

The years with non-exceedance probabilities of 20 percent or less (the driest 20 percent) were selected as dry years. Similarly, the years with exceedance probabilities of 20 percent or less (the wettest 20 percent) were selected as wet years. The remaining 60 percent of the years represent normal years. The hydrologic conditions from year to year vary from location to location (i.e. dry years, wet years, and normal years do not occur at all locations simultaneously). The dry, normal, and wet years selected to represent each drainage are, therefore unique to each geographic location. The years selected to represent dry, wet, and normal hydrologic conditions are summarized on Figure III-8. According to the streamflow records for the Beaver Creek drainage, the hydrologic conditions vary significantly from location to location within the drainage. The wet years, dry years, and normal years for the Beaver Creek drainage are therefore, selected to best represent all locations concurrently.

Figure III-8
Selection of Wet, Dry, and Normal Years for Modeling -
Indicator Stations for the Northeast Wyoming River Basins

click to enlarge

The average monthly and annual streamflow for dry years, normal years, and wet years at the gaged model nodes are provided in Tables III-4, III-5, and III-6 respectively. The average monthly and annual streamflow for dry years, normal years, and wet years at the ungaged model nodes are provided in Tables III-7, III-8, and III-9 respectively.

Table III-4
Summary of Dry Year Monthly and Annual Flows
(1970 to 1999 unless otherwise noted) at Gaged Model Nodes

Basin Station
Number Station Name Natural
Flow Average Streamflow for 1970-1999 in Acre-Feet Note

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Annual

Cheyenne 06364700 Antelope Creek Near Teckla, WY NO 22 24 9 18 38 161 69 39 8 153 27 130 698

06365300 Dry Fork Cheyenne River Near Bill, WY NO 0 1 1 0 2 5 6 4 0 11 0 0 30

06365900 Cheyenne River Near Dull Center, WY NO 33 13 14 30 73 324 128 114 82 447 217 103 1,577

06375600 Little Thunder Chreek Near Hampshire, WY NO 0 0 0 0 0 3 0 3 1 10 1 0 19

06376300 Black Thunder Creek Near Hampshire, WY NO 122 9 0 60 9 70 114 169 176 308 145 92 1,272

06378300 Lodgepole Creek Near Hampshire, WY NO 0 0 0 0 0 5 4 26 11 4 4 0 54

06386000 Lance Creek Near Riverview, WY NO 104 99 41 683 240 273 347 1,008 466 545 511 230 4,547

06386500 Cheyenne River Near Spencer, WY NO 259 216 67 953 430 283 473 1,734 762 187 51 280 5,695

06392900 Beaver Creek at Mallo Camp, Near Four Corners, WY YES 65 61 54 50 62 66 70 72 108 91 81 81 861 Study Period: 1975-1982, 1992-1997

06392950 Stockade Beaver Creek Near Newcastle, WY NO 722 758 744 759 675 759 648 419 506 668 557 664 7,879 Study Period: 1975-1982, 1992-1997

06394000 Beaver Creek Near Newcastle, WY NO 363 762 740 741 756 3,202 1,906 1,411 1,744 1,459 1,187 404 14,674 Study Period: 1975-1982, 1992-1997

06395000 Cheyenne River at Edgemont, SD NO 743 893 430 632 1,264 4,005 1,571 1,081 664 1,148 511 1,871 14,811

Belle Fourche 06425720 Belle Fourche River Below Rattlesnake Creek, Near Piney, WY NO 1 3 7 12 24 53 16 155 55 36 71 5 438

06425780 Belle Fourche River Above Dry Creek Near Piney, WY NO 5 2 6 13 51 128 29 284 56 146 69 13 802

06425900 Caballo Creek at Mouth Near Piney, WY, WY NO 1 12 0 1 7 17 4 50 6 70 7 1 175

06425950 Raven Creek Near Moorcroft, WY YES 0 0 0 0 7 3 0 1 0 0 8 0 20

06426400 Donkey Creek Near Moorcroft, WY NO 4 12 23 17 31 156 29 186 15 3 3 3 481

06426500 Belle Fourche River Below Moorcroft, WY NO 26 70 61 41 464 1,460 299 443 212 1,189 183 71 4,517

USBR Gage Belle Fourche River - Total Keyhole Reservoir Discharge NO 0 0 0 4 2 0 1,272 4,445 4,782 8,563 7,857 995 27,919

06427500 Belle Fourche River Below Keyhole Reservoir, WY NO 106 99 101 105 96 100 1,362 4,476 4,872 8,172 7,803 1,102 28,394

06428200 Belle Fourche River Near Alva, WY NO 763 990 748 372 565 3,225 2,160 4,088 3,941 5,745 6,394 2,123 31,114

06428500 Belle Fourche River at Wyoming-South Dakota State Line NO 870 1,170 863 409 640 4,244 3,332 5,742 4,923 7,172 6,845 2,458 38,668

06429905 Sand Creek Near Ranch A Near Beulah, WY YES 927 1,071 1,063 1,036 906 987 1,028 1,085 996 982 968 979 12,026

06430500 Redwater Creek at Wyoming-South Dakota State Line, WY NO 1,465 1,615 1,582 1,543 1,398 1,642 1,665 1,700 1,671 1,441 1,538 1,577 18,836

Niobrara 06454000 Niobrara River at Wyoming-Nebraska State Line, WY NO 118 130 134 131 138 210 180 185 142 115 115 117 1,716 Study Period: 1970-1994

Table III-5
Summary of Normal Year Monthly and Annual Flows
(1970 to 1999 unless otherwise noted) at Gaged Model Nodes

Basin Station
Number Station Name Natural
Flow Average Streamflow for 1970-1999 in Acre-Feet Note

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Annual

Cheyenne 06364700 Antelope Creek Near Teckla, WY NO 69 27 19 21 199 658 302 516 531 268 179 94 2,882

06365300 Dry Fork Cheyenne River Near Bill, WY NO 2 5 5 2 14 30 16 93 20 14 8 0 209

06365900 Cheyenne River Near Dull Center, WY NO 203 20 23 35 516 816 582 908 1,120 730 491 50 5,494

06375600 Little Thunder Chreek Near Hampshire, WY NO 3 5 6 5 55 61 12 395 120 124 100 2 890

06376300 Black Thunder Creek Near Hampshire, WY NO 317 17 0 27 200 647 286 1,051 699 370 378 335 4,326

06378300 Lodgepole Creek Near Hampshire, WY NO 1 2 1 1 2 40 26 150 79 21 34 1 358

06386000 Lance Creek Near Riverview, WY NO 115 110 93 201 1,040 956 754 2,998 2,471 2,998 2,280 802 14,809

06386500 Cheyenne River Near Spencer, WY NO 186 159 48 695 1,196 748 1,534 14,793 6,889 1,938 511 3,325 32,023

06392900 Beaver Creek at Mallo Camp, Near Four Corners, WY YES 114 102 106 95 95 113 142 154 141 129 122 111 1,421 Study Period: 1975-1982, 1992-1997

06392950 Stockade Beaver Creek Near Newcastle, WY NO 723 713 762 723 694 827 746 600 642 628 658 686 8,400 Study Period: 1975-1982, 1992-1997

06394000 Beaver Creek Near Newcastle, WY NO 520 763 846 815 1,610 5,867 1,840 4,151 2,177 1,597 850 403 21,439 Study Period: 1975-1982, 1992-1997

06395000 Cheyenne River at Edgemont, SD NO 1,744 1,023 741 836 3,785 9,936 4,071 5,678 7,006 4,720 3,922 1,584 45,044

Belle Fourche 06425720 Belle Fourche River Below Rattlesnake Creek, Near Piney, WY NO 7 6 11 24 86 179 61 449 246 93 150 22 1,334

06425780 Belle Fourche River Above Dry Creek Near Piney, WY NO 21 6 14 48 203 484 130 690 292 174 179 68 2,310

06425900 Caballo Creek at Mouth Near Piney, WY, WY NO 13 7 1 11 27 183 30 487 58 81 40 13 951

06425950 Raven Creek Near Moorcroft, WY YES 6 0 0 2 55 96 2 44 1 4 11 0 223

06426400 Donkey Creek Near Moorcroft, WY NO 24 13 24 15 27 1,302 128 1,616 74 14 4 3 3,245

06426500 Belle Fourche River Below Moorcroft, WY NO 846 276 205 494 1,513 3,406 2,128 2,920 1,675 804 418 376 15,059

USBR Gage Belle Fourche River - Total Keyhole Reservoir Discharge NO 191 533 0 0 0 8 629 380 1,340 4,723 4,080 623 12,507

06427500 Belle Fourche River Below Keyhole Reservoir, WY NO 359 371 108 107 98 186 557 374 1,233 4,867 4,192 695 13,147

06428200 Belle Fourche River Near Alva, WY NO 2,083 1,922 1,197 1,347 2,606 6,675 7,476 9,812 6,582 4,667 4,803 1,918 51,086

06428500 Belle Fourche River at Wyoming-South Dakota State Line NO 2,652 2,471 1,445 1,656 3,488 9,328 10,601 15,628 10,124 5,983 5,235 2,267 70,878

06429905 Sand Creek Near Ranch A Near Beulah, WY YES 1,343 1,290 1,274 1,227 1,096 1,236 1,266 1,998 1,772 1,494 1,445 1,329 16,772

06430500 Redwater Creek at Wyoming-South Dakota State Line, WY NO 2,143 2,068 2,038 1,996 1,976 2,280 2,386 4,025 3,077 2,135 2,167 2,096 28,387

Niobrara 06454000 Niobrara River at Wyoming-Nebraska State Line, WY NO 149 144 148 142 157 299 275 257 214 147 172 105 2,210 Study Period: 1970-1994

Table III-6
Summary of Wet Year Monthly and Annual Flows
(1970 to 1999 unless otherwise noted) at Gaged Model Nodes

Basin Station
Number Station Name Natural
Flow Average Streamflow for 1970-1999 in Acre-Feet Note

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Annual

Cheyenne 06364700 Antelope Creek Near Teckla, WY NO 258 217 28 28 162 588 482 6,013 3,421 848 176 52 12,273

06365300 Dry Fork Cheyenne River Near Bill, WY NO 7 13 11 7 43 126 44 687 124 97 14 1 1,174

06365900 Cheyenne River Near Dull Center, WY NO 237 434 46 46 414 1,221 1,289 14,535 7,795 1,635 436 77 28,165

06375600 Little Thunder Chreek Near Hampshire, WY NO 8 7 8 7 74 245 17 2,930 295 291 200 3 4,084

06376300 Black Thunder Creek Near Hampshire, WY NO 464 20 0 115 752 2,218 569 5,615 1,081 1,324 748 1,391 14,298

06378300 Lodgepole Creek Near Hampshire, WY NO 1 3 2 1 4 100 81 638 206 93 61 4 1,193

06386000 Lance Creek Near Riverview, WY NO 215 128 97 379 990 2,883 1,898 17,967 5,708 5,456 3,037 835 39,593

06386500 Cheyenne River Near Spencer, WY NO 559 474 144 2,078 3,418 1,800 5,123 54,135 25,000 4,514 1,091 7,012 105,348

06392900 Beaver Creek at Mallo Camp, Near Four Corners, WY YES 126 122 114 120 123 147 166 148 167 166 138 117 1,655 Study Period: 1975-1982, 1992-1997

06392950 Stockade Beaver Creek Near Newcastle, WY NO 789 770 771 780 739 1,075 918 787 689 760 884 865 9,827 Study Period: 1975-1982, 1992-1997

06394000 Beaver Creek Near Newcastle, WY NO 715 924 829 972 5,219 8,927 3,837 4,062 2,113 1,339 1,321 474 30,731 Study Period: 1975-1982, 1992-1997

06395000 Cheyenne River at Edgemont, SD NO 3,573 3,117 768 859 2,914 10,422 7,592 52,665 30,940 8,293 4,069 1,879 127,090

Belle Fourche 06425720 Belle Fourche River Below Rattlesnake Creek, Near Piney, WY NO 9 9 17 34 115 470 130 1,926 386 189 224 30 3,540

06425780 Belle Fourche River Above Dry Creek Near Piney, WY NO 39 10 22 70 290 1,476 237 3,132 477 531 290 130 6,705

06425900 Caballo Creek at Mouth Near Piney, WY, WY NO 26 18 1 17 47 538 55 2,429 204 182 100 51 3,667

06425950 Raven Creek Near Moorcroft, WY YES 12 0 0 4 99 552 5 254 7 24 23 0 979

06426400 Donkey Creek Near Moorcroft, WY NO 93 38 70 40 74 4,474 310 6,512 282 40 11 8 11,952

06426500 Belle Fourche River Below Moorcroft, WY NO 850 118 70 577 3,802 11,643 4,656 16,641 5,432 1,384 1,138 208 46,519

USBR Gage Belle Fourche River - Total Keyhole Reservoir Discharge NO 0 0 0 0 0 4,378 759 5,162 3,206 1,374 2,531 943 18,353

06427500 Belle Fourche River Below Keyhole Reservoir, WY NO 105 90 91 93 87 4,416 766 5,372 3,239 1,391 2,620 979 19,248

06428200 Belle Fourche River Near Alva, WY NO 2,121 1,487 977 2,462 3,715 15,275 12,966 17,333 13,942 4,878 4,102 2,114 81,370

06428500 Belle Fourche River at Wyoming-South Dakota State Line NO 2,709 1,827 1,162 3,329 5,058 22,710 17,625 25,247 25,372 7,413 4,458 2,423 119,333

06429905 Sand Creek Near Ranch A Near Beulah, WY YES 1,602 1,597 1,539 1,468 1,263 1,460 1,617 2,326 2,566 2,031 2,094 1,704 21,266

06430500 Redwater Creek at Wyoming-South Dakota State Line, WY NO 2,646 2,567 2,517 2,498 2,317 2,718 3,012 4,712 4,772 3,104 3,185 2,730 36,778

Niobrara 06454000 Niobrara River at Wyoming-Nebraska State Line, WY NO 189 191 218 337 427 471 478 286 254 158 125 159 3,293 Study Period: 1970-1994

Table III-7
Summary of Dry Year Monthly and Annual Flows
at Ungaged Natural Flow Nodes

Basin Station Name Estimated Average Streamflow for 1970-1999 in Acre-Feet

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Annual

Cheyenne Willow Creek at Mouth in Section 28, T38N, R72W 1 0 0 0 7 22 0 10 0 1 28 0 43

Woody Creek at Mouth in Section 5, T39N, R69W 0 0 0 0 1 3 0 1 0 0 0 0 5

Lake Creek at Mouth in Section 30, T40N, R68W 0 0 0 0 2 7 0 3 0 0 1 0 13

Sheep Creek at Mouth in Section 7, T40N, R67W 0 0 0 0 1 2 0 1 0 0 0 0 4

Wagonhound Creek at Mouth in Section 31, T41N, R67W 0 0 0 0 1 4 0 2 0 0 0 0 7

Snyder Creek at Mouth in Section 23, T40N, R64W 1 0 0 0 7 21 0 9 0 1 2 0 41

Boggy Creek at Mouth in Section 32, T40N, R63W 0 0 0 0 2 6 0 3 0 0 0 0 11

Sevenmile Creek at Mouth in Section 34, T40N, R63W 0 0 0 0 1 3 0 1 0 0 0 0 5

Mule Creek at Mouth in Section 6, T39N, R61W 0 0 0 0 3 9 0 4 0 0 1 0 17

Robbers' Roost Creek at Mouth in Section 23, T40N, R61W 0 0 0 0 4 13 0 6 0 1 1 0 25

Beaver Creek Just Below Mush Creek in Section 32, T44N, R62W 1 0 0 0 39 16 0 7 0 1 44 0 108

Oil Creek at Mouth in Section 26, T43N, R62W 201 0 0 63 1,739 5,441 84 2,507 73 235 414 0 10,757

Blacktail Creek at Mouth in Section 2, T41N, R61W 182 177 181 181 162 174 183 218 207 198 186 181 2,230

Dry Beaver Creek Just Above Beaver Creek in Section 4, T47N, R60W 65 62 54 51 62 67 71 73 109 92 81 82 869

Belle Fourche Dry Creek at Mouth in Section 29, T47N, R70W 0 0 0 0 2 1 0 0 0 0 2 0 5

Yellow Hammer Creek at Mouth in Section 10, T47N, R70W 0 0 0 0 1 0 0 0 0 0 1 0 2

Whitetail Creek at Mouth in Section 32, T48N, R69W 0 0 0 0 1 0 0 0 0 0 1 0 2

Four Horse Creek at Mouth in Section 11, T48N, R69W 0 0 0 0 10 4 0 2 0 0 11 0 27

Timber Creek at Mouth in Section 2, T48N, R69W 0 0 0 0 3 1 0 0 0 0 3 0 7

Buffalo Creek at Mouth in Section 14, T49N, R68W 0 0 0 0 12 5 0 2 0 0 14 0 33

Donkey Creek Just Upsteam of Gage in Sec. 30, T50N, R68W 0 0 0 902 1,400 1,658 1,367 1,176 676 0 0 0 7,179

Trail Creek at Mouth in Section 24, T50N, R68W 0 0 0 0 1 1 0 0 0 0 2 0 4

Dry Creek at Mouth in Section 24, T50N, R68W 0 0 0 0 2 1 0 0 0 0 2 0 5
Robinson Creek at Mouth in Section 18, T50N, R67W 0 0 0 0 1 0 0 0 0 0 1 0 2

Duck Creek at Mouth in Section 8, T50N, R67W 1 0 0 0 47 18 0 8 0 1 36 0 111

Miller Creek at Mouth in Section 9, T50N, R67W 7 0 0 2 532 200 3 91 3 9 409 0 1,256

Smoke Creek at Mouth in Section 9, T50N, R67W 0 0 0 0 14 5 0 2 0 0 11 0 32

Berger Creek at Mouth in Section 12, T50N, R67W 0 0 0 0 22 8 0 4 0 0 17 0 51
Lone Tree Creek at Mouth in Section 26, T51N, R67W 1 0 0 0 49 18 0 8 0 1 38 0 115

Wind Creek at Mouth in Section 13, T50N, R67W 17 0 0 5 1,218 458 7 208 6 21 935 0 2,875

Deer Creek at Mouth in Section 23, T51N, R67W 4 0 0 1 257 97 1 44 1 5 198 0 608

Eggie Creek at Mouth in Section 21, T51N, R66W 0 0 0 0 36 13 0 6 0 1 27 0 83

Mule Creek at Mouth in Section 15, T50N, R66W 2 0 0 1 156 59 1 27 1 3 120 0 370

Cottonwood Creek at Mouth in Section 35, T51N, R66W 1 0 0 0 41 16 0 7 0 1 32 0 98

Arch Creek at Mouth in Section 11, T51N, R66W 0 0 0 0 8 3 0 2 0 0 9 0 22

Inyan Kara Creek at Mouth in Section 25, T52N, R66W 919 1,051 1,068 1,017 884 960 963 1,061 939 894 896 943 11,595

Cabin Creek at Mouth in Section 14, T52N, R66W 0 0 0 0 6 2 0 1 0 0 7 0 16

Miller Creek at Mouth in Section 12, T52N, R66W 0 0 0 0 5 2 0 1 0 0 6 0 14

Lytle Creek at Mouth in Section 8, T53N, R65W 0 0 0 0 4 1 0 1 0 0 4 0 10

Whitetail Creek at Mouth in Section 14, T54N, R65W 66 76 77 73 63 69 69 76 68 64 64 68 833
Blacktail Creek at Mouth in Section 12, T54N, R65W 168 193 196 186 160 175 176 194 172 164 162 173 2,119

Beaver Creek at Mouth in Section 1, T55N, R64W 368 421 428 407 350 383 386 424 376 358 354 378 4,633

East Creek at Mouth in Section 32, T55N, R63W 38 44 45 42 36 40 40 44 39 37 37 39 481

Arnold Creek at Mouth in Section 28, T55N, R63W 18 20 21 20 17 19 19 21 18 17 17 18 225

Horse Creek at Mouth in Section 19, T56N, R61W 61 69 71 67 58 63 64 70 62 59 58 62 764

Pine Creek at Mouth in Section 33, T56N, R61W 138 158 160 153 131 143 145 159 141 134 133 142 1,737

Kilpatrick Creek at Mouth in Section 3, T55N, R61W 56 64 65 61 53 58 58 64 57 54 54 57 701

Kruger Creek at Mouth in Section 11, T55N, R61W 27 31 31 30 26 28 28 31 28 26 26 28 340

Oak Creek at Mouth in Section 20, T55N, R60W 173 198 201 191 165 180 181 199 177 168 167 178 2,178

South Redwater Creek Just Above Sand Creek in Section 31, T53N, R60W 399 461 458 446 390 425 443 467 429 423 417 422 5,180

Redwater Creek Just Above South Redwater Creek in Section 31, T53N, R60W 203 234 232 227 198 216 225 237 218 215 212 214 2,631

Table III-8
Summary of Normal Year Monthly and Annual Flows
at Ungaged Natural Flow Nodes

Basin Station Name Estimated Average Streamflow for 1970-1999 in Acre-Feet

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Annual

Cheyenne Willow Creek at Mouth in Section 28, T38N, R72W 11 0 0 4 97 188 4 87 3 8 23 0 425

Woody Creek at Mouth in Section 5, T39N, R69W 1 0 0 0 13 25 1 11 0 1 3 0 55

Lake Creek at Mouth in Section 30, T40N, R68W 3 0 0 1 29 57 1 26 1 2 7 0 127

Sheep Creek at Mouth in Section 7, T40N, R67W 1 0 0 0 9 18 0 8 0 1 2 0 39

Wagonhound Creek at Mouth in Section 31, T41N, R67W 2 0 0 1 20 38 1 18 1 2 5 0 88

Snyder Creek at Mouth in Section 23, T40N, R64W 10 0 0 3 91 177 4 82 2 8 22 0 399

Boggy Creek at Mouth in Section 32, T40N, R63W 3 0 0 1 25 48 1 22 1 2 6 0 109

Sevenmile Creek at Mouth in Section 34, T40N, R63W 1 0 0 0 12 24 1 11 0 1 3 0 53

Mule Creek at Mouth in Section 30, T39N, R61W 4 0 0 1 39 76 2 35 1 3 9 0 170

Robbers' Roost Creek at Mouth in Section 23, T40N, R61W 6 0 0 2 55 108 2 50 1 5 13 0 242

Beaver Creek Just Below Mush Creek in Section 32, T44N, R62W 35 0 0 11 299 526 14 243 7 23 60 0 1,218

Oil Creek at Mouth in Section 26, T43N, R62W 402 0 0 49 5,048 5,977 70 2,767 83 261 1,971 0 16,628

Blacktail Creek at Mouth in Section 2, T41N, R61W 199 196 190 180 156 179 187 324 274 244 218 200 2,547

Dry Beaver Creek at Mouth in Section 4, T47N, R60W 115 103 107 96 96 114 143 155 142 130 124 112 1,437

Belle Fourche Dry Creek at Mouth in Section 29, T47N, R70W 2 0 0 1 14 25 1 11 0 1 3 0 58

Yellow Hammer Creek at Mouth in Section 10, T47N, R70W 1 0 0 0 5 9 0 4 0 0 1 0 20

Whitetail Creek at Mouth in Section 32, T48N, R69W 1 0 0 0 8 14 0 6 0 1 2 0 32

Four Horse Creek at Mouth in Section 11, T48N, R69W 9 0 0 3 74 130 3 60 2 6 15 0 302

Timber Creek at Mouth in Section 2, T48N, R69W 2 0 0 1 19 34 1 16 0 1 4 0 78

Buffalo Creek at Mouth in Section 14, T49N, R68W 11 0 0 4 94 165 4 76 2 7 19 0 382

Donkey Creek Just Upsteam of Gage in Sec. 30, T50N, R68W 0 0 0 235 1,126 2,518 1,451 2,883 886 0 0 0 9,100

Trail Creek at Mouth in Section 24, T50N, R68W 1 0 0 0 10 18 0 9 0 1 2 0 41

Dry Creek at Mouth in Section 24, T50N, R68W 2 0 0 1 15 26 1 12 0 1 3 0 61
Robinson Creek at Mouth in Section 18, T50N, R67W 1 0 0 0 4 8 0 4 0 0 1 0 18

Duck Creek at Mouth in Section 8, T50N, R67W 6 0 0 5 60 116 5 53 2 5 21 0 273

Miller Creek at Mouth in Section 9, T50N, R67W 68 0 0 55 689 1,322 58 607 18 57 236 0 3,110

Smoke Creek at Mouth in Section 9, T50N, R67W 2 0 0 1 18 34 1 16 0 1 6 0 79

Berger Creek at Mouth in Section 12, T50N, R67W 3 0 0 2 29 56 2 26 1 2 10 0 131
Lone Tree Creek at Mouth in Section 26, T51N, R67W 6 0 0 5 63 121 5 56 2 5 22 0 285

Wind Creek at Mouth in Section 13, T50N, R67W 156 0 0 126 1,578 3,025 133 1,389 41 130 540 0 7,118

Deer Creek at Mouth in Section 23, T51N, R67W 33 0 0 27 333 639 28 293 9 27 114 0 1,503

Eggie Creek at Mouth in Section 21, T51N, R66W 5 0 0 4 46 88 4 41 1 4 16 0 209

Mule Creek at Mouth in Section 15, T50N, R66W 20 0 0 16 202 387 17 178 5 17 69 0 911

Cottonwood Creek at Mouth in Section 35, T51N, R66W 5 0 0 4 54 103 5 47 1 4 18 0 241

Arch Creek at Mouth in Section 11, T51N, R66W 8 0 0 2 63 111 3 51 2 5 13 0 258

Inyan Kara Creek at Mouth in Section 25, T52N, R66W 1,199 1,143 1,138 1,116 1,037 1,231 1,146 1,820 1,641 1,397 1,401 1,207 15,476

Cabin Creek at Mouth in Section 14, T52N, R66W 6 0 0 2 48 84 2 39 1 4 10 0 196

Miller Creek at Mouth in Section 12, T52N, R66W 5 0 0 1 40 70 2 32 1 3 8 0 162

Lytle Creek at Mouth in Section 8, T53N, R65W 3 0 0 1 27 48 1 22 1 2 5 0 110

Whitetail Creek at Mouth in Section 14, T54N, R65W 86 82 82 80 69 79 82 127 118 100 100 87 1,092
Blacktail Creek at Mouth in Section 12, T54N, R65W 218 209 208 204 176 201 209 322 300 255 254 221 2,777

Beaver Creek at Mouth in Section 1, T55N, R64W 477 458 456 446 385 439 458 704 657 557 555 483 6,075

East Creek at Mouth in Section 32, T55N, R63W 50 48 47 46 40 46 48 73 68 58 58 50 632

Arnold Creek at Mouth in Section 28, T55N, R63W 23 22 22 22 19 21 22 34 32 27 27 23 294

Horse Creek at Mouth in Section 19, T56N, R61W 79 76 75 74 63 72 75 116 108 92 92 80 1,002

Pine Creek at Mouth in Section 33, T56N, R61W 179 172 171 167 144 165 172 264 246 209 208 181 2,278

Kilpatrick Creek at Mouth in Section 3, T55N, R61W 72 69 69 67 58 66 69 106 99 84 84 73 916

Kruger Creek at Mouth in Section 11, T55N, R61W 35 34 33 33 28 32 34 52 48 41 41 36 447

Oak Creek at Mouth in Section 20, T55N, R60W 224 215 214 210 181 207 215 331 309 262 261 227 2,856

South Redwater Creek Just Above Sand Creek in Section 31, T53N, R60W 579 556 549 529 472 533 545 860 763 644 623 572 7,225

Redwater Creek Just Below South Redwater Creek in Section 31, T53N, R60W 294 282 279 268 240 270 277 437 388 327 316 291 3,669

Table III-9
Summary of Wet Year Monthly and Annual Flows
at Ungaged Natural Flow Nodes

Basin Station Name Estimated Average Streamflow for 1970-1999 in Acre-Feet

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Annual

Cheyenne Willow Creek at Mouth in Section 28, T38N, R72W 10 0 0 3 83 601 5 276 8 26 20 0 1,032

Woody Creek at Mouth in Section 5, T39N, R69W 1 0 0 0 11 79 1 36 1 3 3 0 135

Lake Creek at Mouth in Section 30, T40N, R68W 3 0 0 1 25 182 2 84 2 8 6 0 313

Sheep Creek at Mouth in Section 7, T40N, R67W 1 0 0 0 8 58 0 27 1 2 2 0 99

Wagonhound Creek at Mouth in Section 31, T41N, R67W 2 0 0 1 17 121 1 56 2 5 4 0 209

Snyder Creek at Mouth in Section 23, T40N, R64W 9 0 0 3 77 563 5 259 7 24 18 0 965

Boggy Creek at Mouth in Section 32, T40N, R63W 3 0 0 1 21 154 1 71 2 7 5 0 265

Sevenmile Creek at Mouth in Section 34, T40N, R63W 1 0 0 0 10 75 1 35 1 3 2 0 128

Mule Creek at Mouth in Section 6, T39N, R61W 4 0 0 1 33 242 2 111 3 10 8 0 414

Robbers' Roost Creek at Mouth in Section 23, T40N, R61W 6 0 0 2 47 343 3 158 5 15 11 0 590

Beaver Creek Just Below Mush Creek in Section 32, T44N, R62W 63 0 0 20 539 3,018 30 1,388 40 130 128 0 5,356

Oil Creek at Mouth in Section 26, T43N, R62W 225 0 0 71 1,950 6,374 1,364 2,810 82 263 4,838 0 17,977

Blacktail Creek at Mouth in Section 2, T41N, R61W 220 211 211 204 182 226 210 283 282 272 239 211 2,751

Dry Beaver Creek Just Above Beaver Creek in Section 4, T47N, R60W 127 124 115 122 125 148 168 149 169 168 139 118 1,672

Belle Fourche Dry Creek at Mouth in Section 29, T47N, R70W 3 0 0 1 25 142 1 65 2 6 6 0 251

Yellow Hammer Creek at Mouth in Section 10, T47N, R70W 1 0 0 0 9 53 1 24 1 2 2 0 93

Whitetail Creek at Mouth in Section 32, T48N, R69W 2 0 0 1 14 78 1 36 1 3 3 0 139

Four Horse Creek at Mouth in Section 11, T48N, R69W 16 0 0 5 133 746 7 343 10 32 32 0 1,324

Timber Creek at Mouth in Section 2, T48N, R69W 4 0 0 1 35 195 2 90 3 8 8 0 346

Buffalo Creek at Mouth in Section 14, T49N, R68W 20 0 0 6 169 947 9 436 13 41 40 0 1,681

Donkey Creek Just Upsteam of Gage in Sec. 30, T50N, R68W 0 0 0 102 879 5,657 1,848 7,956 1,275 0 0 0 17,717

Trail Creek at Mouth in Section 24, T50N, R68W 2 0 0 1 19 106 1 49 1 5 5 0 189

Dry Creek at Mouth in Section 24, T50N, R68W 3 0 0 1 26 148 1 68 2 6 6 0 261
Robinson Creek at Mouth in Section 18, T50N, R67W 1 0 0 0 8 45 0 21 1 2 2 0 80

Duck Creek at Mouth in Section 8, T50N, R67W 4 0 0 1 37 153 2 71 2 7 9 0 286

Miller Creek at Mouth in Section 9, T50N, R67W 49 0 0 15 425 1,750 22 805 23 75 101 0 3,265

Smoke Creek at Mouth in Section 9, T50N, R67W 1 0 0 0 11 45 1 21 1 2 3 0 85

Berger Creek at Mouth in Section 12, T50N, R67W 2 0 0 1 18 74 1 34 1 3 4 0 138
Lone Tree Creek at Mouth in Section 26, T51N, R67W 5 0 0 1 39 161 2 74 2 7 9 0 300

Wind Creek at Mouth in Section 13, T50N, R67W 113 0 0 35 973 4,004 50 1,843 53 173 232 0 7,476

Deer Creek at Mouth in Section 23, T51N, R67W 24 0 0 7 206 846 11 389 11 36 49 0 1,579

Eggie Creek at Mouth in Section 21, T51N, R66W 3 0 0 1 28 117 1 54 2 5 7 0 218

Mule Creek at Mouth in Section 15, T50N, R66W 14 0 0 5 125 512 6 236 7 22 30 0 957

Cottonwood Creek at Mouth in Section 35, T51N, R66W 4 0 0 1 33 136 2 63 2 6 8 0 255

Arch Creek at Mouth in Section 11, T51N, R66W 13 0 0 4 114 639 6 294 8 28 27 0 1,133

Inyan Kara Creek at Mouth in Section 25, T52N, R66W 1,255 1,227 1,126 1,049 1,145 1,900 1,242 2,233 1,905 1,511 1,448 1,259 17,300

Cabin Creek at Mouth in Section 14, T52N, R66W 10 0 0 3 86 483 5 222 6 21 21 0 857

Miller Creek at Mouth in Section 12, T52N, R66W 8 0 0 3 71 399 4 184 5 17 17 0 708

Lytle Creek at Mouth in Section 8, T53N, R65W 6 0 0 2 49 276 3 127 4 12 12 0 491

Whitetail Creek at Mouth in Section 14, T54N, R65W 89 88 81 75 73 81 89 135 137 107 102 91 1,148
Blacktail Creek at Mouth in Section 12, T54N, R65W 227 225 206 191 185 207 226 344 347 271 259 231 2,919

Beaver Creek at Mouth in Section 1, T55N, R64W 496 491 451 418 404 452 495 753 759 592 567 505 6,383

East Creek at Mouth in Section 32, T55N, R63W 52 51 47 44 42 47 51 78 79 62 59 53 665

Arnold Creek at Mouth in Section 28, T55N, R63W 24 24 22 20 20 22 24 36 37 29 27 24 309

Horse Creek at Mouth in Section 19, T56N, R61W 82 81 74 69 67 75 82 124 125 98 94 83 1,054

Pine Creek at Mouth in Section 33, T56N, R61W 186 184 169 157 151 169 185 282 285 222 213 189 2,392

Kilpatrick Creek at Mouth in Section 3, T55N, R61W 75 74 68 63 61 68 75 114 115 89 86 76 964

Kruger Creek at Mouth in Section 11, T55N, R61W 36 36 33 31 30 33 36 55 56 43 42 37 468

Oak Creek at Mouth in Section 20, T55N, R60W 233 231 212 197 190 213 232 354 357 278 267 237 3,001

South Redwater Creek Just Above Sand Creek in Section 31, T53N, R60W 690 688 663 632 544 629 697 1,002 1,105 875 902 734 9,161

Redwater Creek Just Below South Redwater Creek in Section 31, T53N, R60W 350 349 337 321 276 319 354 509 561 444 458 373 4,651

Spreadsheet Model Development and Calibration

Water availability spreadsheet models were developed for the following four sub-basins within the Northeast Wyoming River Basins planning area:

Belle Fourche River sub-basin
Redwater Creek sub-basin
Beaver Creek sub-basin
Cheyenne River sub-basin

The models do not explicitly account for water rights, appropriations, or compact allocations nor are the models operated based on these legal constraints. Further, the models do not associate supplemental reservoir releases to the specific water users. However, by calibrating the models to historical streamflows at gaged locations, the models can be used to generally represent existing operations.

The models developed for this plan are intended to simulate water use and availability under existing conditions. For each sub-basin, three models were developed, reflecting each of the three hydrologic conditions (dry, normal, and wet years). The models each represent one calendar year of flows, on a monthly time step. Streamflow, estimated actual diversions, full supply diversions, irrigation returns, and reservoir conditions are the basic input data to the models. For all of these data, average values drawn from the dry, normal, or wet years of the study period were computed for use in the spreadsheets.

Theoretical Maximum Diversion Requirements were calculated using the acreage of irrigated lands mapped through this study and the consumptive irrigation requirements (CIR) provided by Dr. Larry Pochop. Lacking historical diversion data specific to the planning area, relationships between historical diversion records and Theoretical Maximum Diversions developed for the neighboring Powder/Tongue River Basin were used to calculate the Estimated Actual Diversions and the Full Supply Diversion Requirements for all modeled irrigated lands. A more detailed discussion of this process is offered in the "Agricultural Use" technical memorandum.

Development of the model and the model inputs (primarily streamflows, estimated actual diversions and the interrelated irrigation efficiencies and irrigation return flows) progressed somewhat concurrently in order to achieve calibration. The model representation of the physical system and the various model inputs were adjusted as necessary through a trial and error process until the models were reasonably well calibrated.

To mathematically represent each sub-basin, the river system was divided into reaches based primarily upon the location of major tributary confluences. Each reach was then sub-divided by identifying a series of individual nodes representing diversions, reservoirs, tributary confluences, gages, or other significant water resources features. The resulting network is a simplified representation of actual conditions. For example, the Belle Fourche River model consists of reaches with tributaries grouped together. Figures III-9 through III-12 present node diagrams of the sub-basin models developed for the planning area.

click to enlarge

Historical or virgin flow for each month is supplied to the model at the uppermost node. Where available, upper basin gages were selected as the uppermost model nodes; in their absence, flow at the ungaged headwater point was estimated as discussed in a preceding section. For each reach, incremental stream gains (e.g., ungaged tributaries, ground water inflow, and inflow resulting from man-induced but unmodeled processes) and losses (e.g. seepage, evaporation, and unspecified diversions) are computed by the spreadsheet. These are calculated by adding the net modeled effects (diversions and increases in storage less return flows and decreases in storage) within the basin back into the difference between the upstream and downstream historical gage flows.

At each node, a water budget computation is completed to determine the amount of water that bypasses the node. At non-storage nodes, the difference between inflow, including upstream inflows, return flows, imports and basin gains, and outflows, including diversions, basin losses and exports, is the amount of flow available to the next node downstream. For storage nodes, an additional loss calculation for evaporation and the change in storage is evaluated. Also at storage nodes, any uncontrolled spill that occurs is added to the scheduled release to determine total outflow. Diverted amounts at diversion nodes are the minimum of demand (the full supply diversion at the structure) and physically available streamflow. The mass balance, or water budget calculations, is performed for all nodes in a reach.

Model output includes the full-supply diversion demand and model simulated diversions at each of the diversion points, and streamflow at each of the Powder/Tongue River sub- basin model nodes. Estimates of impacts associated with various water projects can be analyzed by changing input data, as decreases in available streamflow or as changes to diversions occur. New storage projects that alter the timing of streamflows or shortages may also be evaluated.

Model Development and Structure

The model was developed using Microsoft® Excel 97. The workbooks contain macros written in the Microsoft® Visual Basic for Applications programming language. The primary function of the macros is to facilitate navigation within the workbook.

Each of the Powder/Tongue River sub-basin models is a workbook consisting of numerous individual pages (worksheets). Each worksheet is a component of the model and completes a specific task required for execution of the model. There are five basic types of worksheets:

Navigation Worksheets: Graphical User Interfaces (GUIs) containing buttons used to move within the workbook;
Input Worksheets: Raw data entry worksheets (USGS Gage data or headwater inflow data, Diversion Data, etc.);
Computation Worksheets: Compute various components of the model (reservoir evaporation, irrigation return flows, etc.);
Reach/Node Worksheets: Calculate node by node computations of the water budget; and
Results Worksheets: Tabulate and present the model output.

A more detailed description of the development of the spreadsheet models is provided in the "Spreadsheet Model Development and Calibration" technical memorandum.

Determination of Available Surface Water

The estimated amount of water flowing through each of the various model reaches, as previously described, provides the primary basis for determining how much water is physically available for future development. Reaches are typically defined by gages or confluences, and represent tributary basins or subsections of the mainstem. A Reach Outflow worksheet is provided in each model, summarizing the monthly flow at the downstream end of each reach. The information provided in these summaries is used for this analysis.

While simulated flow at the reach terminus indicates the estimated amount of water physically present, it does not fully reflect availability. Downstream demands relying on the water physically available at any given location must first be accounted for. These downstream demands fall into three general categories:

Existing irrigation, or municipal diversions
Instream flow constraints
Compact constraints

Available Flow in Excess of Existing Diversion Demands

To determine how much of the physical supply is actually available in excess of existing demands, "available flow" at each reach terminus is defined as the minimum of the physically available flow at that point, and the "available flow" at all downstream reaches. Thus available flow must be defined first at the most downstream point, with upstream availability calculated in stream order. These calculations are made on a monthly basis, and annual water availability is computed as the sum of monthly values.

Instream Flow Constraints

Instream flow rights exert a demand on the river but do not affect physical supply, because the water is not removed from the stream. Sufficient flow must be bypassed through upstream reaches to satisfy downstream instream flow requirements. The available flow for reaches located upstream from permitted instream flows are determined as the minimum of physical flow at that point, and available flow in excess of existing diversion demands less the instream flow requirement at the downstream reach.

There is only one permitted instream flow right in the planning area for a 2.5-mile reach of Sand Creek in the Redwater Creek drainage. The available flow in Reach 1 of the Redwater Creek sub-basin was calculated taking this instream flow demand into consideration.

The reach by reach results of the monthly available flow determination, accounting for the instream flow constraints, are provided in Tables III-10 through III-21 for each of the four sub-basins and for each of the three hydrologic conditions (wet, normal, and dry years). The total annual available flow is summarized in Table III-22 for each sub-basin and hydrologic condition. The locations of these available flows are also shown graphically on Figures III-13 through III-16 for the limiting dry year conditions.

Table III-10
Available Flow for Redwater Creek Basin (Acre-Feet) -
Wet Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Sand Creek ¹ 484 478 643 865 1,808 2,087 1,381 1,382 946 495 347 247 10,680

2 South Redwater Creek 632 588 701 762 1,158 1,192 833 862 672 689 688 663 8,808

3 S Redwater Cr below Sand Cr 2,137 1,980 2,341 2,586 4,108 4,374 2,946 2,981 2,558 2,308 2,236 2,190 30,607

4 Redwater Creek 321 299 356 365 504 398 159 204 172 338 331 327 3,453

5 Redwater Cr beow S Redwater Cr 2,498 2,317 2,718 3,012 4,712 4,772 3,104 3,185 2,730 2,646 2,567 2,517 34,279

Note: ¹Coinstrained by Instream Flow Rights of 16 cfs (January 1 - April 30), 18 cfs (May 1 - October 31), and 21 cfs (November 1 - December 31).

Table III-11
Available Flow for Redwater Creek Basin (Acre-Feet) -
Normal Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Sand Creek ¹ 244 270 379 494 1,462 1,126 836 839 565 238 40 0 6,249

2 South Redwater Creek 529 499 587 592 992 717 568 602 500 577 556 549 6,738

3 S Redwater Cr below Sand Cr 1,737 1,685 1,964 2,048 3,603 2,956 2,128 2,117 2,022 1,874 1,804 1,776 23,977

4 Redwater Creek 259 253 298 274 401 121 8 50 74 269 264 263 2,274

5 Redwater Cr beow S Redwater Cr 1,996 1,976 2,280 2,386 4,025 3,077 2,135 2,167 2,096 2,143 2,063 2,038 26,391

Note: ¹Coinstrained by Instream Flow Rights of 16 cfs (January 1 - April 30), 18 cfs (May 1 - October 31), and 21 cfs (November 1 - December 31).

Table III-12
Available Flow for Redwater Creek Basin (Acre-Feet) -
Dry Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Sand Creek ¹ 52 18 3 59 287 335 248 202 152 0 0 0 1,303

2 South Redwater Creek 446 390 425 391 420 362 315 355 306 445 461 458 4,329

3 S Redwater Cr below Sand Cr 1,343 1,216 1,426 1,417 1,673 1,671 1,441 1,538 1,577 1,285 1,411 1,379 16,034

4 Redwater Creek 200 182 216 153 27 0 0 0 0 180 204 203 1,164

5 Redwater Cr beow S Redwater Cr 1,543 1,398 1,642 1,665 1,700 1,671 1,441 1,538 1,577 1,465 1,615 1,582 17,293

Note: ¹Coinstrained by Instream Flow Rights of 16 cfs (January 1 - April 30), 18 cfs (May 1 - October 31), and 21 cfs (November 1 - December 31).

Table III-13
Available Flow for Beaver Creek Basin (Acre-Feet) -
Wet Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Beaver Cr above Oil Cr 33 635 1,752 0 1,011 0 50 5 0 73 36 22 3,585

2 Oil Creek 71 2,281 3,700 1,887 1,348 0 0 1,245 0 118 0 0 10,578

3 Beaver Cr above Blacktail Cr 149 2,916 5,452 1,971 2,359 176 184 1,250 53 204 172 99 14,836

4 Blacktail Cr 159 209 131 340 166 727 351 31 130 95 148 152 2,480

5 Beaver Cr above Stockdale Beaver Cr 308 3,125 5,583 2,311 2,525 903 535 1,281 183 299 320 251 17,317

6 Dry Beaver Creek 117 139 203 194 79 137 143 3 49 72 108 99 1,226

7 Beaver Cr in South Dakota 116 138 201 192 79 136 141 3 49 72 107 98 1,214

8 Stockdale Beaver Cr Tribs above Gage 06392950 415 429 649 495 292 416 423 9 161 262 389 382 3,907

9 Stockdale Beaver Cr above Gage 06392950 648 739 1,075 880 451 689 707 15 259 407 604 578 6,403

10 Stockdale Beaver Cr above Mouth 648 1,373 1,288 880 451 1,175 707 15 259 407 604 587 7,737

11 Stockdale Beaver Cr Tribs above Mouth 10 438 1,251 0 667 0 49 0 0 9 0 0 2,414

12 Beaver Cr Tribs above Gage 06394000 6 282 804 0 396 0 16 0 0 1 0 0 1,499

13 Beaver Cr above Gage 06394000 972 5,219 8,927 3,822 4,038 2,079 1,308 1,296 422 715 924 829 29,599

14 Beaver Cr above Stateline 977 5,221 8,929 3,822 4,038 2,079 1,308 1,296 422 727 936 836 29,635

Table III-14
Available Flow for Beaver Creek Basin (Acre-Feet) -
Normal Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Beaver Cr above Oil Cr 16 79 399 0 132 0 0 0 0 12 17 8 647

2 Oil Creek 49 1,320 4,532 0 2,591 0 0 437 0 178 0 0 9,057

3 Beaver Cr above Blacktail Cr 118 1,399 4,931 25 2,963 135 182 696 55 189 145 104 10,822

4 Blacktail Cr 135 40 136 475 311 865 482 115 157 64 127 149 2,921

5 Beaver Cr above Stockdale Beaver Cr 253 1,439 5,067 502 3,333 999 664 811 212 253 271 253 13,805

6 Dry Beaver Creek 93 15 63 159 48 116 117 0 29 48 82 103 779

7 Beaver Cr in South Dakota 92 15 62 157 48 115 115 0 29 47 81 102 772

8 Stockdale Beaver Cr Tribs above Gage 06392950 369 51 208 424 199 411 396 0 90 172 328 387 2,667

9 Stockdale Beaver Cr above Gage 06392950 554 81 333 746 295 642 628 0 148 267 492 592 4,224

10 Stockdale Beaver Cr above Mouth 554 81 333 977 295 1,135 893 0 148 267 492 592 5,213

11 Stockdale Beaver Cr Tribs above Mouth 5 55 284 0 113 0 0 0 0 0 0 0 452

12 Beaver Cr Tribs above Gage 06394000 3 35 183 0 39 0 0 0 0 0 0 0 257

13 Beaver Cr above Gage 06394000 815 1,610 5,867 1,824 4,129 2,134 1,557 811 360 520 763 846 20,421

14 Beaver Cr above Stateline 821 1,614 5,870 1,824 4,129 2,134 1,557 811 360 536 779 855 20,468

Table III-15
Available Flow for Beaver Creek Basin (Acre-Feet) -
Dry Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Beaver Cr above Oil Cr 2 14 9 0 0 0 0 0 0 0 3 2 28

2 Oil Creek 63 625 3,045 0 953 0 0 0 0 95 0 0 4,718

3 Beaver Cr above Blacktail Cr 78 639 3,054 38 953 298 337 310 144 95 127 55 6,050

4 Blacktail Cr 127 57 97 572 113 915 717 139 225 46 115 137 3,134

5 Beaver Cr above Stockdale Beaver Cr 205 697 3,152 626 1,066 1,212 1,106 590 368 142 242 192 9,393

6 Dry Beaver Creek 56 6 5 91 41 94 55 63 0 28 65 61 509

7 Beaver Cr in South Dakota 56 6 5 90 41 94 54 62 0 28 64 60 504

8 Stockdale Beaver Cr Tribs above Gage 06392950 424 32 30 467 221 300 209 254 0 165 391 427 2,496

9 Stockdale Beaver Cr above Gage 06392950 536 43 41 648 304 488 317 379 0 221 520 548 3,509

10 Stockdale Beaver Cr above Mouth 536 43 41 933 304 488 317 379 0 221 520 548 3,794

11 Stockdale Beaver Cr Tribs above Mouth 0 10 6 0 0 0 0 0 0 0 0 0 16

12 Beaver Cr Tribs above Gage 06394000 0 6 4 0 0 0 0 0 0 0 0 0 10

13 Beaver Cr above Gage 06394000 741 756 3,202 1,887 1,370 1,701 1,424 1,162 368 363 762 740 13,734

14 Beaver Cr above Stateline 746 759 3,205 1,887 1,370 1,701 1,424 1,162 368 377 777 749 13,778

Table III-16
Available Flow for Cheyenne River Basin (Acre-Feet) -
Wet Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Dry Fork Cheyenne River 8 35 9 118 1,354 287 113 9 0 7 22 13 1,967

2 Dry Fork Cheyenne River Tribs above Gage 06365900 8 167 102 0 1,062 0 0 0 0 9 0 0 1,341

3 Willow Creek 3 62 38 13 518 18 30 15 0 10 0 0 704

4 Woody Creek 0 8 5 0 0 0 0 0 0 0 0 0 13

5 Lake Creek 1 19 12 4 157 5 9 5 0 3 0 0 213

6 Dry Fork Cheyenne River above Antelope Cr 20 292 166 141 3,237 384 152 29 9 37 35 18 4,501

7 Antelope Creek 25 122 37 1,148 11,263 7,410 756 81 69 174 338 28 21,427

8 Cheyenne River above Gage 06365900 46 414 203 1,289 14,535 7,795 908 110 77 211 378 46 25,968

9 Cheyenne River above Sheep Cr 148 489 203 1,756 19,607 13,390 908 110 222 211 378 46 37,321

10 Cheyenne River Tribs above Gage 06386500 46 461 473 0 1,046 0 0 0 0 0 0 0 1,980

11 Sheep Creek 1 9 10 0 0 0 0 0 0 0 0 0 19

12 Wagonhound Creek 2 20 20 0 20 0 0 0 0 0 0 0 60

13 Cheyenne River above Black Thunder Cr 224 996 707 1,756 20,862 13,390 908 110 222 211 378 84 39,624

14 Black Thunder Creek 375 888 369 680 7,434 1,540 595 134 4,195 228 15 0 16,078

15 Cheyenne River above Lodgepole Cr 612 1,891 1,075 2,436 28,332 14,929 1,504 244 4,417 439 393 85 55,745

16 Lodgepole Creek 3 4 17 91 834 294 24 1 0 0 2 1 1,268

17 Cheyenne River above Snyder Cr 616 1,896 1,092 2,527 29,165 15,223 1,528 245 4,417 439 395 86 57,013

18 Snyder Cr 9 91 94 0 289 0 0 0 0 0 0 0 474

19 Cheyenne River above Boggy Cr 635 1,993 1,185 2,527 29,461 15,223 1,528 245 4,417 439 395 86 57,500

20 Boggy Creek 3 25 26 0 71 0 0 0 0 0 0 0 122

21 Cheyenne River above Lance Cr 638 2,018 1,211 2,527 29,532 15,223 1,528 245 4,417 439 395 86 57,621

22 Seven Mile Creek 1 12 12 0 41 0 0 0 0 0 0 0 65

23 Lance Creek 1,233 1,170 479 2,596 24,203 9,777 2,987 845 2,594 119 79 59 44,909

24 Mule Creek 4 39 40 0 0 0 0 0 0 0 0 0 80

25 Cheyenne River above Robbers' Roost Cr 1,876 3,240 1,742 5,123 53,775 25,000 4,514 1,091 7,012 559 474 144 102,675

26 Robbers' Roost Creek 6 56 57 0 26 0 0 0 0 0 0 0 138

27 Cheyenne River above Gage 06386500 2,078 3,418 1,800 5,123 54,135 25,000 4,514 1,091 7,012 559 474 144 103,270

28 Cheyenne River above above Stateline 2,084 3,422 1,801 5,125 54,140 25,002 4,517 1,094 7,030 586 490 154 103,362

Table III-17
Available Flow for Cheyenne River Basin (Acre-Feet) -
Normal Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Dry Fork Cheyenne River 2 6 3 30 106 42 26 3 0 2 5 5 244

2 Dry Fork Cheyenne River Tribs above Gage 06365900 9 108 55 0 0 0 0 0 0 20 0 0 183

3 Willow Creek 3 40 21 10 97 6 18 15 0 11 0 0 225

4 Woody Creek 0 5 3 0 0 0 0 0 0 0 0 0 8

5 Lake Creek 1 12 6 3 29 2 5 4 0 3 0 0 68

6 Dry Fork Cheyenne River above Antelope Cr 16 171 88 44 335 88 50 22 5 41 7 8 860

7 Antelope Creek 18 83 72 530 573 1,032 355 69 45 50 13 16 2,837

8 Cheyenne River above Gage 06365900 35 254 160 573 908 1,120 405 90 50 91 20 23 3,696

9 Cheyenne River above Sheep Cr 57 254 160 573 2,589 1,922 405 90 128 91 20 23 6,341

10 Cheyenne River Tribs above Gage 06386500 27 225 174 0 0 0 0 0 0 0 0 0 399

11 Sheep Creek 1 5 4 0 0 0 0 0 0 0 0 0 8

12 Wagonhound Creek 1 10 7 0 0 0 0 0 0 0 0 0 17

13 Cheyenne River above Black Thunder Cr 113 493 345 573 2,821 1,922 405 90 128 91 95 26 7,074

14 Black Thunder Creek 44 97 126 196 2,696 903 53 16 834 69 12 0 5,120

15 Cheyenne River above Lodgepole Cr 169 590 471 769 5,568 2,825 458 106 962 160 107 26 12,193

16 Lodgepole Creek 1 1 8 8 368 80 0 0 0 0 1 0 480

17 Cheyenne River above Snyder Cr 170 591 479 777 5,936 2,905 458 106 962 160 108 27 12,674

18 Snyder Cr 5 44 34 0 101 0 0 0 0 0 0 0 187

19 Cheyenne River above Boggy Cr 186 635 513 777 6,074 2,905 458 106 962 160 108 27 12,861

20 Boggy Creek 1 12 9 0 11 0 0 0 0 0 0 0 34

21 Cheyenne River above Lance Cr 188 646 522 777 6,085 2,905 458 106 962 160 108 27 12,895

22 Seven Mile Creek 1 6 5 0 18 0 0 0 0 0 0 0 29

23 Lance Creek 332 498 186 756 8,465 3,984 1,480 405 2,363 26 51 22 18,323

24 Mule Creek 2 19 15 0 0 0 0 0 0 0 0 0 33

25 Cheyenne River above Robbers' Roost Cr 523 1,169 727 1,534 14,567 6,889 1,938 511 3,325 186 159 48 31,280

26 Robbers' Roost Creek 3 26 21 0 0 0 0 0 0 0 0 0 47

27 Cheyenne River above Gage 06386500 695 1,196 748 1,534 14,793 6,889 1,938 511 3,325 186 159 48 31,328

28 Cheyenne River above above Stateline 702 1,200 750 1,538 14,800 6,894 1,944 518 3,344 216 177 59 31,434

Table III-18
Available Flow for Cheyenne River Basin (Acre-Feet) -
Dry Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Dry Fork Cheyenne River 0 2 2 6 1 0 6 0 0 0 1 1 24

2 Dry Fork Cheyenne River Tribs above Gage 06365900 1 19 26 0 0 0 0 0 0 0 0 0 44

3 Willow Creek 0 7 10 1 33 7 1 2 0 1 0 0 60

4 Woody Creek 0 1 1 0 0 0 0 0 0 0 0 0 2

5 Lake Creek 0 2 3 0 10 2 0 0 0 0 0 0 18

6 Dry Fork Cheyenne River above Antelope Cr 2 31 42 7 44 9 7 2 4 8 2 2 164

7 Antelope Creek 18 38 70 94 70 52 74 13 72 22 11 9 534

8 Cheyenne River above Gage 06365900 30 73 112 102 114 61 81 16 75 33 13 14 705

9 Cheyenne River above Sheep Cr 30 73 112 102 138 61 81 16 75 33 13 14 707

10 Cheyenne River Tribs above Gage 06386500 1 33 36 0 0 0 0 0 0 0 0 0 69

11 Sheep Creek 0 1 1 0 0 0 0 0 0 0 0 0 1

12 Wagonhound Creek 0 1 2 0 0 0 0 0 0 0 0 0 3

13 Cheyenne River above Black Thunder Cr 57 123 150 102 138 61 81 16 75 116 100 49 1,007

14 Black Thunder Creek 60 9 24 19 58 97 6 0 0 1 9 0 358

15 Cheyenne River above Lodgepole Cr 130 140 174 121 196 158 87 16 75 188 146 49 1,482

16 Lodgepole Creek 0 0 2 0 0 0 0 0 0 0 0 0 9

17 Cheyenne River above Snyder Cr 130 140 176 121 196 158 87 16 75 188 147 49 1,491

18 Snyder Cr 0 7 7 0 0 0 0 0 0 0 0 0 14

19 Cheyenne River above Boggy Cr 143 154 183 121 196 158 87 16 75 188 147 49 1,511

20 Boggy Creek 0 2 2 0 0 0 0 0 0 0 0 0 4

21 Cheyenne River above Lance Cr 143 155 185 121 196 158 87 16 75 188 147 49 1,515

22 Seven Mile Creek 0 1 1 0 0 0 0 0 0 0 0 0 2

23 Lance Creek 683 240 91 353 1,538 604 100 35 204 71 69 18 3,184

24 Mule Creek 0 3 3 0 0 0 0 0 0 0 0 0 6

25 Cheyenne River above Robbers' Roost Cr 826 399 279 473 1,734 762 187 51 280 259 216 67 4,706

26 Robbers' Roost Creek 0 4 4 0 0 0 0 0 0 0 0 0 8

27 Cheyenne River above Gage 06386500 953 430 283 473 1,734 762 187 51 280 259 216 67 4,742

28 Cheyenne River above above Stateline 959 435 286 478 1,743 776 204 68 304 295 237 79 4,911

Table III-19
Available Flow for Belle Fourche River Basin (Acre-Feet) -
Wet Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Belle Fourche River above Caballo Cr 43 44 212 253 732 1,380 0 0 0 24 0 13 2,658

2 Belle Fourche River Tribs above Gage 06426500 5 34 182 0 101 0 0 0 0 10 0 0 328

3 Caballo Creek 11 7 77 58 568 589 0 0 0 16 0 1 1,316

4 Dry Cr, Yellow Hammer CR, Whitetail CR, & Four Horse Cr 4 27 146 11 110 39 0 0 0 13 0 0 346

5 Belle Fourche River above Buffalo Cr 63 112 618 323 1,511 2,008 0 0 0 63 0 13 4,648

6 Raven Creek 2 15 79 6 60 22 0 0 0 6 0 0 187

7 Buffalo Cr & Timber Cr 4 31 164 0 17 0 0 0 0 2 0 0 214

8 Belle Fourche River above Donkey Cr 69 157 862 329 1,588 2,030 0 0 0 71 0 13 5,049

9 Donkey Creek 161 148 845 2,063 1,801 3,402 0 0 0 68 0 44 8,371

10 Trail Cr, Dry Cr, & Robinson Cr 1 8 43 0 8 0 0 0 0 0 0 0 59

11 Belle Fourche River above Gage 06426500 231 314 1,750 2,391 3,397 5,432 0 0 0 139 0 57 13,479

12 Belle Fourche River above Keyhole Reservoir 231 314 1,750 2,391 3,397 6,133 0 0 0 139 0 57 14,181

13 Tribs to Keyhole Reservoir 7 37 281 0 148 0 0 0 0 8 0 0 474

14 Miller Cr, Lone Tree Cr, Deer Cr, & Eggie Cr 10 58 432 8 247 0 0 0 0 13 0 0 757

15 Duck Cr, Smoke Cr, Berger Cr, Wind Cr, Mule Cr, & Cottonwood Cr 17 99 740 20 438 0 0 0 0 22 0 0 1,319

16 Keyhole Reservoir 265 508 3,202 2,420 4,230 6,133 0 0 0 181 0 57 16,731

17 Belle Fourche River above Inyan Kara Cr 265 508 3,202 2,420 4,230 6,499 0 0 0 181 0 57 17,096

18 Belle Fourche River Tribs above Gage 06428200 247 531 2,674 1,552 2,690 1,771 0 0 0 158 0 45 9,422

19 Arch Cr, Inyan Kara Cr, Cabin Cr, & Miller Cr 491 637 2,997 2,930 3,249 3,822 0 0 0 580 668 199 15,082

20 Belle Fourche River above Whitetail Cr 1,003 1,676 8,872 6,902 10,169 12,091 1,364 0 0 919 668 301 42,964

21 Whitetail Cr, Blacktail Cr, Lytle Cr, & Beaver Cr 726 1,384 5,165 4,440 5,427 4,778 0 0 0 481 164 175 22,013

22 Belle Fourche River above Gage 06428200 1,729 3,060 14,037 11,342 15,597 16,869 2,223 0 0 1,400 832 476 65,836

23 Belle Fourche River above Arnold Cr 1,729 3,060 14,037 11,342 15,597 18,643 3,408 0 0 1,400 832 476 68,795

24 Belle Fourche River Tribs above Gage 06428500 970 2,233 6,574 3,777 6,391 3,896 0 0 0 780 428 458 24,537

25 Arnold Cr & East Cr 592 2,012 6,126 3,244 5,645 2,330 0 0 0 274 0 145 19,776

26 Belle Fourche River above Horse Cr 3,291 7,305 26,738 18,364 27,633 24,869 4,691 256 0 2,453 1,260 1,080 114,649

27 Horse Cr, Pine Cr, Kruger Cr, Kilpatrick Cr, & Oak Cr 1,222 4,706 11,718 5,395 9,981 3,430 0 0 0 677 60 412 36,379

28 Belle Fourche River above Stateline 4,513 12,011 38,456 23,759 37,615 28,299 4,758 256 0 3,130 1,320 1,491 151,096

Table III-20
Available Flow for Belle Fourche River Basin (Acre-Feet) -
Normal Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Belle Fourche River above Caballo Cr 8 9 33 87 141 318 0 0 0 29 0 10 618

2 Belle Fourche River Tribs above Gage 06426500 1 6 15 0 0 0 0 0 0 9 0 0 24

3 Caballo Creek 2 1 13 20 100 63 0 0 0 18 0 0 209

4 Dry Cr, Yellow Hammer CR, Whitetail CR, & Four Horse Cr 1 5 12 3 17 3 0 0 0 17 0 0 51

5 Belle Fourche River above Buffalo Cr 11 21 73 110 258 383 0 0 0 72 0 11 915

6 Raven Creek 0 2 7 2 10 2 0 0 0 8 0 0 29

7 Buffalo Cr & Timber Cr 1 5 14 0 0 0 0 0 0 0 0 0 19

8 Belle Fourche River above Donkey Cr 12 29 93 112 267 385 0 0 0 80 0 11 963

9 Donkey Creek 56 59 187 1,166 565 917 0 0 0 103 0 49 3,031

10 Trail Cr, Dry Cr, & Robinson Cr 0 1 4 0 0 0 0 0 0 0 0 0 5

11 Belle Fourche River above Gage 06426500 68 89 283 1,278 832 1,302 0 0 0 183 0 60 3,999

12 Belle Fourche River above Keyhole Reservoir 68 89 283 1,278 832 1,302 0 0 0 183 0 60 3,999

13 Tribs to Keyhole Reservoir 8 43 117 17 144 0 0 0 0 14 0 0 334

14 Miller Cr, Lone Tree Cr, Deer Cr, & Eggie Cr 13 67 180 44 248 0 0 0 0 23 0 0 563

15 Duck Cr, Smoke Cr, Berger Cr, Wind Cr, Mule Cr, & Cottonwood Cr 21 115 309 84 448 0 0 0 0 40 0 0 995

16 Keyhole Reservoir 110 314 890 1,423 1,672 1,302 0 0 0 260 0 60 5,892

17 Belle Fourche River above Inyan Kara Cr 110 314 890 1,423 1,672 2,643 0 0 0 260 0 60 7,262

18 Belle Fourche River Tribs above Gage 06428200 97 324 930 832 1,354 0 0 0 0 116 0 35 3,569

19 Arch Cr, Inyan Kara Cr, Cabin Cr, & Miller Cr 253 431 1,275 1,975 3,169 1,952 0 0 0 607 535 311 10,281

20 Belle Fourche River above Whitetail Cr 460 1,069 3,094 4,230 6,194 4,665 0 0 0 984 1,184 406 21,804

21 Whitetail Cr, Blacktail Cr, Lytle Cr, & Beaver Cr 309 844 2,289 2,651 4,154 1,878 0 0 0 438 130 216 12,562

22 Belle Fourche River above Gage 06428200 769 1,913 5,384 6,881 10,349 6,544 0 0 0 1,421 1,314 622 34,366

23 Belle Fourche River above Arnold Cr 769 1,913 5,384 6,881 10,349 8,199 0 0 0 1,421 1,314 622 36,051

24 Belle Fourche River Tribs above Gage 06428500 606 1,312 2,919 2,083 3,057 1,409 0 0 0 728 335 502 12,327

25 Arnold Cr & East Cr 283 1,068 2,561 1,526 2,055 87 0 0 0 201 0 97 7,578

26 Belle Fourche River above Horse Cr 1,658 4,293 10,864 10,489 15,461 9,731 0 0 0 2,350 1,863 1,221 56,200

27 Horse Cr, Pine Cr, Kruger Cr, Kilpatrick Cr, & Oak Cr 674 2,357 5,179 2,517 3,199 111 0 0 0 560 0 362 14,358

28 Belle Fourche River above Stateline 2,332 6,650 16,043 13,007 18,660 10,086 0 0 0 2,910 1,863 1,584 70,803

Table III-21
Available Flow for Belle Fourche River Basin (Acre-Feet) -
Dry Year Hydrologic Conditions

Reach Reach Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1 Belle Fourche River above Caballo Cr 0 0 13 0 0 0 0 0 0 0 0 1 14

2 Belle Fourche River Tribs above Gage 06426500 0 0 1 0 0 0 0 0 0 0 0 0 1

3 Caballo Creek 0 0 2 0 0 0 0 0 0 0 0 0 2

4 Dry Cr, Yellow Hammer CR, Whitetail CR, & Four Horse Cr 0 0 1 0 0 0 0 0 0 0 0 0 1

5 Belle Fourche River above Buffalo Cr 0 1 16 0 0 0 0 0 0 0 0 1 17

6 Raven Creek 0 0 0 0 0 0 0 0 0 0 0 0 0

7 Buffalo Cr & Timber Cr 0 0 1 0 0 0 0 0 0 0 0 0 1

8 Belle Fourche River above Donkey Cr 0 1 17 0 0 0 0 0 0 0 0 1 18

9 Donkey Creek 0 8 188 0 0 0 0 0 0 0 0 4 200

10 Trail Cr, Dry Cr, & Robinson Cr 0 0 0 0 0 0 0 0 0 0 0 0 0

11 Belle Fourche River above Gage 06426500 0 9 205 0 0 0 0 0 0 0 0 5 219

12 Belle Fourche River above Keyhole Reservoir 0 9 205 0 0 0 0 0 0 0 0 5 219

13 Tribs to Keyhole Reservoir 0 11 30 0 0 0 0 0 0 0 0 0 41

14 Miller Cr, Lone Tree Cr, Deer Cr, & Eggie Cr 0 17 46 0 0 0 0 0 0 0 0 0 63

15 Duck Cr, Smoke Cr, Berger Cr, Wind Cr, Mule Cr, & Cottonwood Cr 0 29 79 0 0 0 0 0 0 0 0 0 108

16 Keyhole Reservoir 0 65 361 0 0 0 0 0 0 0 0 5 431

17 Belle Fourche River above Inyan Kara Cr 4 65 361 0 0 0 0 0 0 0 0 17 443

18 Belle Fourche River Tribs above Gage 06428200 0 61 339 0 0 0 0 0 0 0 0 1 402

19 Arch Cr, Inyan Kara Cr, Cabin Cr, & Miller Cr 49 104 571 0 0 0 0 0 0 0 309 173 1,158

20 Belle Fourche River above Whitetail Cr 53 230 1,271 472 0 0 0 0 0 0 309 192 2,474

21 Whitetail Cr, Blacktail Cr, Lytle Cr, & Beaver Cr 28 178 1,027 0 0 0 0 0 0 0 46 100 1,351

22 Belle Fourche River above Gage 06428200 81 408 2,298 774 0 0 0 0 266 0 355 292 4,394

23 Belle Fourche River above Arnold Cr 81 408 2,298 801 0 0 0 0 266 0 355 292 4,420

24 Belle Fourche River Tribs above Gage 06428500 189 443 1,328 0 0 0 0 0 0 0 253 343 2,368

25 Arnold Cr & East Cr 9 293 1,038 0 0 0 0 0 0 0 0 27 1,358

26 Belle Fourche River above Horse Cr 279 1,144 4,664 1,459 143 0 0 0 601 0 608 663 9,282

27 Horse Cr, Pine Cr, Kruger Cr, Kilpatrick Cr, & Oak Cr 106 741 2,128 0 0 0 0 0 0 0 0 205 3,073

28 Belle Fourche River above Stateline 385 1,885 6,792 1,946 143 0 0 0 601 0 608 868 12,843

Table III-22
Total Annual Available Flow

Subbasin Hydrologic Condition

Wet Years Normal Years Dry Years

Redwater Creek 34,000 26,000 17,000

Beaver Creek 30,000 20,000 14,000

Cheyenne River 103,000 31,000 5,000

Belle Fourche River 151,000 71,000 13,000

The yield potential of each of these basins is limited by the dry year conditions. Further, the timing of these available flows does not necessarily match the timing of the demand for this water. For example of the 14,000 acre-feet of available flow from Beaver Creek during a typical dry year, roughly 60 percent of this occurs during the months of March through June. Reservoir storage would be required to store this excess flow to satisfy demands throughout the year. The available flow presented in Table III-22 does not include the constraints of the Belle Fourche River Compact. This will be discussed in the next section.

Compact Constraints

A determination of the amount of water available to Wyoming for future development is not complete without an evaluation of the constraints imposed by interstate compacts. Three interstate compacts have been negotiated between the States of Wyoming, Montana, North Dakota, and South Dakota for divisions of the waters of the Little Missouri River, the Belle Fourche River, and the Cheyenne River. Of these three compacts, only the Belle Fourche River Compact has been formally accepted by all interests.

The Belle Fourche Compact of 1943 is briefly summarized by the following rules for dividing the waters between the States of Wyoming and South Dakota (SEO, 1982):

All existing rights in the two states as of the date of the compact are recognized;

Wyoming is allowed unlimited use for domestic and stock purposes, provided that no stock reservoir exceeds 20 acre-feet;

The unappropriated waters of the Belle Fourche River and it's tributaries as of the date of the compact, as measured at the Wyoming-South Dakota State line, are allocated as follows:
90 percent to South Dakota
10 percent to Wyoming

If a reservoir is constructed in Wyoming principally for the irrigation of lands in South Dakota, sufficient water not to exceed 10 cfs shall be released at all times for stock water use. Wyoming has the right to purchase storage space, not exceeding 10 percent of the total space, in any reservoir or reservoirs constructed in Wyoming for irrigation of lands in South Dakota.

No reservoir built solely to use the water allocated to Wyoming shall have a capacity in excess of 1,000 acre-feet.

The following methodology was utilized in determining the amount of water subject to the 90% / 10% apportionment:

Annual measured streamflow at the USGS Gages 06428500 (Belle Fourche River at Wyoming- South Dakota State Line and 06430500 (Redwater Creek at Wyoming-South Dakota State Line) are used as the basic data for this evaluation. The surface water hydrology work for this study was performed on a water year basis (October 1 through September 30). Determination of the compact apportionment was therefore also performed on a water year basis for consistency. The compact, however, specifies that apportionment shall be determined based on the accumulated flow and storage from the beginning of the calendar year. Average annual wet year, normal year, and dry year streamflow for the water years selected through the surface water hydrology work were compared to the corresponding calendar year streamflows. This analysis, performed for the Belle Fourche River, indicated a difference for all three conditions of less than 0.3 percent. Very little error is introduced into the analysis through the use of water-year total annual flows.

The streamflow at the USGS Gages 06428500 (Belle Fourche River at WY-SD State Line) is adjusted to reflect the annual change in storage of Keyhole Reservoir.
The streamflows are further adjusted by adding back estimated annual depletions for post compact water uses in Wyoming. These depletions are estimated as the Crop Irrigation Requirements (CIR) for the roughly 2060 acres of land served from the mainstem of the Belle Fourche River below Keyhole Reservoir and the 140 acres of land in the Redwater Creek drainage.
Bypass requirements for pre compact water uses in South Dakota are subtracted from the state line flows. According to the USBR, there are roughly 1025 acres in South Dakota served from the Belle Fourche River by pre compact water rights. Based on water rights data received from the South Dakota Department of Environment and Natural Resources, there are also 928 acres of land irrigated from Redwater Creek between the State Line and the confluence of Spearfish Creek. It is assumed that major tributaries in South Dakota (Crow Creek and Spearfish Creek) supply the water requirements of the lands on the lower reaches of Redwater Creek. The average annual streamflow of these two tributaries alone total more than twice the average annual streamflow of Redwater Creek at the State Line. The diversion requirement for those lands requiring bypass water (1025 acres and 928 acres) is estimated at 2.14 acre-feet per acre, based on information obtained from the NRCS in South Dakota.

Wyoming's Compact allocation is taken as 10 percent of the adjusted annual streamflows at the State Line. Wyoming's apportionment of the Belle Fourche River under the three hydrologic conditions (wet, normal, and dry years) is summarized in Table III-23.

Table III-23
Wyoming's Apportionment of Available Flow Per
Belle Fourche River Compact

Hydrologic Condition Average Annual Apportionment (AF)

Belle Fourche
River Redwater
Creek Total

Wet Years 15,600 3,300 18,900

Normal Years 7,400 2,400 9,800

Dry Years 1,100 1,400 2,500

Additional detail of the determination of available flows is provided in the "Available Surface Water Determination" technical memorandum. The Wyoming Water Planning Program previously estimated Wyoming's average annual apportionment of the Belle Fourche River to be 7,300 acre-feet for the 1948 through 1968 study period.

B. Ground Water

A qualitative summary of the ground water resources of the Little Missouri, Belle Fourche, Cheyenne and Niobrara basins of northeastern Wyoming is presented herein. Collectively, these basins are referred to as the Northeast Wyoming River Basins (planning area).

Study Objectives

The first objective of this task was to inventory and catalog the Wyoming State Engineer's Office (SEO) ground water permit database for various categories of ground water uses in the planning area, and incorporate the extracted information into six GIS data layers. This was accomplished through a cooperative effort with personnel of the SEO and Wyoming Water Development Commission (WWDC). GIS data layers prepared from information on file with the SEO as of December 31, 2000 included:

Permitted active agricultural wells with production rates greater than 49 gpm
Permitted active municipal wells with production rates greater than 49 gpm
Permitted active industrial and miscellaneous wells with production rates greater than 49 gpm
Active permitted domestic wells
Active permitted stock wells
Permitted coalbed methane wells

Because of the dynamic nature of CBM development in the planning area, the permitted CBM well data was recollected from the SEO database near the end of this planning effort. The permitted CBM wells are therefore current as of December 31, 2001. The second objective of this task was to inventory and document existing published data on ground water studies and ground water planning documents for the planning area. Some of the existing ground water studies and ground water planning documents overlap the geographic boundaries of the planning area and include the drainage basins of the Tongue and Powder Rivers.

Other objectives are as follows:

Summarize existing information on aquifers with regards to location, storage, yield and development potential within the planning area.
Summarize the potential effects that ground water development might have on the ground water and surface water systems in the basins within the planning area.
Characterize coalbed methane development and its short and long-term effects on ground water and surface water supplies within the planning area.

It is intended that the information provided herein along with the GIS data layers and the bibliography of previous investigations will provide a starting point for site specific ground water investigations.

Study Methods

There were no original investigations performed as part of this task. The work consisted of performing an inventory, compilation and review of published literature on the geology and ground water resources of the planning area.

There is a wealth of published and unpublished reports of investigations on the geology and ground water resources of the Basin Plan area. The Powder River Structural Basin (PRSB), part of which is within the planning area, has been the subject of investigation and exploration as a result of interest in the development of energy and natural resources for at least the last 40 to 50 years. Resources of interest have included oil and gas, coal, uranium, coalbed methane and water.

A bibliography of published ground water studies and ground water planning documents for the Basin Plan is included in the "Available Ground Water Determination" technical memorandum. The references included in the bibliography, provide sources for an overview of ground water resources, and of some of the interests and concerns that have arisen as a result of the various stages of development of energy and natural resources in the planning area.

Additional information in specific geographic areas within the planning area is available through the U.S. Geological Survey (USGS) and other federal agencies. Two additional federal agencies active in ground water related issues in the PRSB include the U. S. Bureau of Land Management (BLM) and the U. S. Environmental Protection Agency (USEPA).

Several Wyoming State agencies have site specific information available in the planning area. These agencies include the Department of Environmental Quality (Land Quality and Water Quality Divisions), the State Engineer's Office, the United States Geological Survey, the Oil and Gas Conservation Commission and the Water Development Commission.

Overview

The planning area lies in the northeastern and east-central part of the state and includes all or part of seven Wyoming counties (Figure I-1). The planning area includes all of Weston, most of Crook and about forty percent of Campbell (central/east, south and southeast and northeast) Counties. The northeast and northwest parts of Converse and Niobrara Counties, respectively, as well as small parts of Natrona and Goshen Counties are also within the planning area. Figure III- 17 shows the general location of the planning area with respect to regional structural elements in northeastern Wyoming.

Major communities in Campbell and Crook Counties include: Gillette, Wright, Hulett, Moorcroft, and Sundance. Newcastle and Upton are the primary towns in Weston County. Principal towns in Niobrara County include Lusk, Manville and Redbird.

Regionally, the planning area lies within the Missouri River drainage system and covers an area of approximately 11,943 square miles in northeastern Wyoming. The principal surface water systems within the planning area include the Little Missouri, Belle Fourche, Cheyenne and Niobrara Rivers and their respective tributaries. These drainage systems form the boundary of the planning area.

Altitudes are variable, generally ranging from 4200 feet (southwestern Crook County) to 5,500 feet (northwest of Lusk in Niobrara County) in the western part of the planning area. Altitudes in the eastern part of the planning area generally vary from 4,700 feet (Niobrara County at the Wyoming . Nebraska State line) to 6,600 feet (northeastern Converse County) to 4,750 feet at the crest of Bear Mountain in Crook County. The lowest altitude in the planning area is about 3,125 feet where the Belle Fourche River crosses the state line in Crook County.

Climate is typical of the northern High Plains with low precipitation, high evaporation and wide ranges of temperatures. Annual precipitation varies from 13 to 15 inches in the lowlands to well over 20 inches per year in the Black Hills (Figure I-2). Generally, about fifty percent of the precipitation in the planning area occurs between April and July.

Geologic Setting

Geologic formations in the planning area range in geologic time from Precambrian crystalline rocks to recent alluvial and eolian deposits generally consisting of clays, silts, sands and gravels. The PRSB, part of which is within the planning area, has over 17,000 feet of sedimentary strata. These sedimentary rocks have been divided into about 11,000 feet of Cambrian to Cretaceous pretectonic deposits and up to 7,000 feet of Tertiary deposits associated with the deformation of the PRSB. (Feathers, Libra, Stephenson and Eisen, 1981, Occurrence and Characteristics of Groundwater in the Powder River Basin, Wyoming)

The older strata, which are exposed only in the northeastern part of the Basin Plan Area, are economically important for oil production. The Tertiary deposits generally present in the west- central portion of the planning area contain significant coal reserves and are subject to mining and coalbed methane development. Both the Early Cretaceous Fall River Formation and the Early Tertiary Wasatch Formation have been important as uranium deposit sources in the Black Hills and the central to southcentral part of the planning area. Figure III-18 presents a generalized geologic section of the PRSB including part of the planning area.

The planning area encompasses several tectonic elements that influence the geology and the occurrence and availability of ground water in the planning area. These structural features include the PRSB, mountain uplifts (Black Hills, Laramie Range and Bighorn Mountains) and broad uplifts of lesser magnitude (Hartville Hills and the Casper Arch).

Figures III-19 and III-20 present the generalized surficial and bedrock geology of the planning area.

click to enlarge

Geologic Units and Ground Water

A geologic formation is a body or group of rock strata that consist dominantly of a certain lithologic type or combination of types. A general definition of an aquifer is a geologic formation or group of formations that are capable of yielding a significant quantity of water to wells or springs.

There are more than 30 geologic formations exposed on the margins of the PRSB. For this report, the formations were grouped into six principal aquifer systems that have historically been the major ground water sources of interest in the planning area. The grouping was based on those presented in the 1981 report "Occurrence and Characteristics of Ground Water in the Powder River Basin, Wyoming" by the Wyoming Water Resources Research Institute (WWRI) of Wyoming. Figure III-21 graphically summarizes the geologic formations and their hydrogeologic role in the PRSB within the planning area.

The WWRI aquifer system division and the grouping used herein were based on aquifer hydrogeologic similarity and aquitard identification. The grouping allows for a simplified presentation of the principal sources of ground water in the planning area. The six major aquifer systems within the planning area are (oldest to youngest):

Madison Aquifer System
Dakota Aquifer System
Fox Hills/Lance Aquifer System
Fort Union/Wasatch Aquifer System
Tertiary Aquifer
Quaternary Aquifer System

More detailed information on the hydrologic characteristics of the major aquifer systems are provided in the "Available Ground Water Determination" technical memorandum.

Figure III-21. Diagramatic Hydrostratigraphy of the Powder River Structural Basin
within the Northeast Wyoming River Basins Plan Area.

Figure Source: Feathers, Libra, Stephenson & Eisen, 1981
Occurrence and Characteristics of Groundwater in the Powder River Basin, Wyoming

Ground Water Quality

Ground water quality data contained in USGS ground water reports for the planning area were reviewed and provide an overview of the general quality of water from the aquifer systems within the planning area.

The review included selected USGS analyses available from USGS data files as of March 26, 1982 (Larson and Daddow, 1984, Ground-Water-Quality Data from the Powder River Structural Basin and Adjacent Areas, Northeastern Wyoming). The 2000 USGS publication on water co-produced with coalbed methane in the PRSB was also reviewed (Rice, Ellis and Miller, 2000, Water Co-produced with Coalbed Methane in the Powder River Basin, Wyoming: Preliminary Data).

1984 USGS Report

Information used in the 1984 report did not include all of the information available in USGS files at the time. Constituents were selected by USGS on the basis of their relative abundance and their inclusion in water quality criteria at the time. Water quality data available from the 1984 USGS report included: specific conductance, pH, temperature, dissolved-solids (TDS) concentration and concentrations of the major ions (calcium, magnesium, sodium, potassium, alkalinity (as bicarbonate), sulfate, chloride, fluoride, and nitrate, plus silica, boron, and iron). This data was from 748 ground water sites in the PRSB and adjacent areas.

Information on selected dissolved trace metals were reported for 220 ground water sites in the PRSB and adjacent areas in the 1984 USGS report. Data were reported for nine trace metals (arsenic, barium, cadmium chromium copper, lead, mercury, selenium, zinc) in the 1982 selection.

Radiochemical data was listed for 65 ground water sites in the PRSB and adjacent areas in the 1984 USGS report. The data included eight radiochemical analyses for each site (gross alpha- dissolved, gross alpha-suspended, gross beta-dissolved, gross beta-suspended, radium 226 dissolved radon method, radium 226 dissolved precipitation method, uranium-dissolved extraction method, uranium-dissolved direct fluorometric method).

2000 USGS Report

The 2000 USGS publication on water co-produced with coalbed methane in the PRSB contained data from 47 ground water sites in the PRSB. Approximately 32 of the sites were located within the planning area. The remaining 15 were located in the Powder/Tongue River Basin Plan Area.

Water quality data available from the 2000 USGS report included: pH, temperature, dissolved- solids (TDS) concentration and concentrations of the major ions and minor ions (fluoride, chloride, sulfate, bromine, alkalinity, ammonia, calcium, potassium, magnesium, sodium, barium, iron plus silica, strontium, and sodium-adsorption-ratio (SAR)). Data was also reported for seventeen trace elements (silver, aluminum, arsenic, boron, beryllium, bismuth, cadmium, cerium, cobalt, chromium, caesium, copper, mercury, lanthanum, lithium, manganese, nickel).

Water Quality Standards and Suitability for Use

The State of Wyoming has identified the following as standards for different classes of ground water:

Class I ground water is defined as ground water suitable for domestic use.
Class II ground water is defined as ground water suitable for agricultural use where soil conditions and other factors are adequate.
Class III ground water is defined as ground water suitable for stock use.
Class Special (A) ground water is defined as ground water suitable for fish and aquatic life.
Class IV ground water is defined as ground water suitable for industry.
Class V ground water is defined as ground water found closely associated with commercial deposits of hydrocarbons, or ground water which is considered a geothermal resource.
Class VI ground water is defined as ground water that may be unusable or unsuitable for use.

Historically, major ground water uses in the planning area have been for domestic use, agriculture (stock and irrigation), and municipal/public water systems. A principal ground water use or withdrawal has been for industrial purposes including, coalbed methane production, petroleum production (secondary oil recovery) and refining, coal mining, coal fired steam generation, and uranium mining and processing. Ground water has also been used to support fish and aquatic life including fish hatcheries.

The fact that ground water is and has been successfully used for the above uses is a general, practical indicator of ground water quality in the planning area. A general, qualitative evaluation and comparison of ground water produced from the six aquifer systems was performed. The results of the evaluation, including a general characterization of water co-produced with coalbed methane are summarized in Table III-24. The general availability and development potential for each aquifer system in the planning area are also summarized in Table III-24.

Aquifer Sensitivity/Vulnerability

The University of Wyoming's Spatial Data and Visualization Center (SDVC . now known as the Wyoming Geographic Information Science Center or WyGISC) developed a system to assess the sensitivity and vulnerability of ground water to surface water contamination in Wyoming. The SDVC developed aquifer vulnerability maps to define the potential for surface contamination to impact ground water in the uppermost aquifer throughout Wyoming. The highest rated lands generally are located on alluvial deposits adjacent to rivers, streams, and lakes, and are associated with slope wash, colluvium, residuum and eolian deposits or are on fractured bedrock areas.

Maps of aquifer vulnerability to contamination for the uppermost or shallowest aquifers were also developed by SDVC. Ground water is vulnerable in areas with high water tables, sandy soils, and areas of presumed pesticide application. The areas with the highest vulnerability are also generally located in the floodplains of the major streams and/or associated with slope wash, colluvium, residuum and eolian deposits within the planning area.

The ground water sensitivity and vulnerability maps are provided in the "Available Ground Water Determination" technical memorandum.

Ground Water Development

Ground water is the major and in many cases, the only source of water within the Basin Plan Area. All six aquifer systems are important water sources in the planning area for all uses. As an example, ground water from each of the aquifer systems has historically been used at one time or another as a source for municipal/public water systems in the planning area. Ground water associated/co-produced with coalbed methane development although not a use, is very important due to withdrawal impacts on water levels and existing wells completed in the Fort Union/Wasatch Aquifer System.

Existing Development

Selected existing and historical uses of ground water from the six aquifer systems within the planning area are summarized in Table III-24. The significance of ground water in the planning area is demonstrated by the 15,793 active ground water permits (as of December 31, 2000) within the planning area. The number of permits for each use category are summarized below:

308 Permitted active agricultural wells with production rates greater than 49 gpm
76 Permitted active municipal wells with production rates greater than 49 gpm
608 Permitted active industrial and miscellaneous wells with production rates greater than 49 gpm
2,760 Active permitted domestic wells
6,756 Active permitted stock wells
5,285 Permitted coalbed methane wells (6657 by December 31, 2001)

The geographic distribution of the permits for the above use categories with respect to surficial and bedrock geology are presented in the "Available Ground Water Determination" memorandum. Two of these maps showing CBM wells and stock wells in relation to the bedrock geology are shown on Figures III-22 and III-23. These maps provide a general indication of the significance of the geologic formations associated with each of the aquifer systems as ground water sources in the planning area.

Table III-24
Summary of Ground Water Availability/Development Potential of Major Aquifer
Systems, Central and Eastern Flanks of the Powder River Structural Basin

Major Aquifer System Geologic Unit Thickness
(Feet) Lithologic Character Hydrological Character^A,B General Water
Quality Availability/Development
Potential^C Remarks

Quaternary Alluvial Aquifer System Alluvium and Terrace
Deposits 0-100+ Clay rich sandy silt, silt, sand and gravel; unconsolidated and interbedded; present along most streams. Thickness generally less than 50 feet but may be thicker. Coarser deposits in valleys of the Belle Fourche and the Cheyenne Rivers. Alluvium overlying formations of Tertiary age is generally fine to medium grained in central part of basin. (Hodson, Pearl and Druse, 1971) Yield of 1000 gpm possible, often through induced recharge. Terraces topographically high and often drained. Specific capacity, 0.3-18 gpm/ft; porosity, 28-45%; permeability, 0.1-1100 gpd/ft2; transmissivity, 15-64000 gpd/ft; specific yield, 2-39%. Coarser deposits have better aquifer properties. TDS content generally range from about 100 to >4000 mg/l, and chemical characteristics of water differ geographically. Chemical type and mineralization of the water can be expected to vary depending on underlying rock types and the nature and degree of interconnection with underlying bedrock aquifers as well as surface water. Moderate to high mineralization tolerable for stock and domestic use. Suitability for irrigation generally limited to salt tolerant crops. Water in the alluvium in Black Hills generally is better quality than central part of basin (Hodson, Pearl and Druse, 1971). Historical source for domestic and stock use. Production has ranged from 1 to 900 gpm. Ground water development potential generally better in coarse-grained deposits and poorer in fine-grained materials. Yields in the high end of the above range might be possible to optimally located and properly designed wells if induced infiltration from surface water can be tolerated (Belle Fourche, Cheyenne and Niobrara River Basins). Potential source for irrigation, municipal / public and industrial sources where more than 40 feet of saturated well sorted sand and gravel are present. Quaternary alluvial aquifers generally in hydraulic connection with all bedrock aquifers in outcrop areas and also with surface waters. Alluvial aquifers in larger valleys provide hydraulic interconnection between otherwise hydraulically isolated bedrock aquifers (Whitcomb, 1965). Alluvial aquifers also serve as interchange point and storage for ground water in the hydrologic cycle (Davis and Rechard, 1977), (Davis, 1976). Induced recharge from surface waters is probable in areas of extensive development.

Middle Tertiary Aquifer Arikaree Formation 0-500
(southeast only) Tuffaceous sandstone, fine-grained with silty zones, coarse sand lenses and concretionary zones. Yields up to 1000 gpm; specific capacity up to 232 gpm/ft; porosity, 5-24%; permeability <1-300 gpd/ft2; transmissivity up to 77,000 gpd/ft. TDS content of water ranges from 261 to 535 mg/l. Composition mainly Calcium Bicarbonate (Whitcomb, 1965). Median TDS content in samples from 12 wells in Niobrara County 321 mg/l (Larson, 1984). Historical source for municipal / public, industrial, domestic, stock and irrigation supply with tested production ranging as high as 195 to 730 gpm (Whitcomb, 1965). Yields of 1000 gpm might be possible to optimally located and properly designed wells. Water level data available from two observation wells located east and south east of Lusk in Niobrara County (32-62-05-baa01), (32-62-32-bbb01). Water levels have shown approximately 6 to 13 feet decline in water levels in the aquifer since the 1970s with possibly some stabilization and slight recovery since early to mid 1990s (USGS, 2001).

Fort Union / Wasatch Aquifer System Wasatch Formation up to 1600 Fine- to coarse-grained lenticular sandstones interbedded with shale and coal, coarser in south. Yields generally <15 gpm, locally flowing wells exist. Yields historically could be expected to range from 10 to 50 gpm in the north part of the basin with the possibility of higher yields up to 500 gpm in the south part of the basin (Hodson, Pearl and Druse, 1973). Specific capacity, 0.10-14 gpm/ft (Hodson, Pearl and Druse, 1973); porosity, 28-30%; permeability, 0.01-65 gpd/ft2; transmissivity, average 500 gpd/ft range 1-4000 gpd/ft. TDS content of waters is variable and ranges from <200 to > 8000 mg/l (Hodson, Pearl and Druse, 1973). Sodium Sulfate and Sodium Bicarbonate are general dominate water types. Major ion composition varies with depth and shows more Sodium and Bicarbonate content with depth. Radium 226 + 228 may be of concern near uranium deposits. Historical source for municipal / public, domestic and stock supply. Yields ranging from 10 to 50 gpm in the north part of the basin can be expected with the possibility of higher yields up to 500 gpm in the south part of the basin (Hodson, Pearl and Druse, 1973). Water level data available from two observation wells located in Campbell County (50-72-21-aba01), (42-71-35-aaa01) and one observation well in Converse County (37-70-10-cbb01). Water levels in the aquifer have shown about a 40 feet rise between 1983 and 2000 in Gillette and about a 40 to 50 feet decline south east of Wright in Campbell County. Water levels in the aquifer in northwest Converse County have shown a rise of about 7 feet between 1988 and 1999 after a decline of about 6 feet between 1986 and 1988. (USGS, 2001)

Fort Union Formation 1100-2270 Sandstone, fine- to medium-grained, lenticular, interbedded with siltstone, coal and shale. Middle part may be shalier in north, upper part siltier in south. "Clinker" associated with coal outcrops. Flowing yields of 1-60 gpm where confined. Pumped yields up to 250 gpm with several hundred feet of drawdown. Specific capacity, 0.1-2 gpm/ft; permeability, 0.01-100 gpd/ft2; transmissivity, 1-5000 gpd/ft. Coal and clinker generally have better aquifer properties than sandstones. Locally clinker transmissivity up to 3,000,000 gpd/ft; Anisotropy and leaky confining layers are common. TDS content and major ion composition of Fort Union Formation Waters as above. Water co-produced with coal bed methane is predominantly Sodium Bicarbonate type with TDS content and SAR (32 samples), 270 - 1170 mg/l (mean of 653 mg/l) and 5.7 - 12 (mean of 7.85) respectively (Rice, Ellis & Bullock, 2000). BLM Wyodak EIS assumed average TDS concentration of 764 mg/l (USDI,BLM, 1999). High radionuclide content of concern in areas near uranium ore zones. Historical source for municipal / public, domestic and stock supply. Maximum expected yields of about 130 to 150 gpm (Hodson, Pearl and Druse, 1973), (Wester -Wetstein and Associates, Inc., 1994). Exploration and development of new Fort Union well field including conjunctive use / recharge of Coal Bed Methane production water under consideration \for the City of Gillette. Source for approximately 14 municipal and public water supply systems including the City of Gillette and adjacent Districts, Joint Powers Boards and Privately Owned Water Systems and Water Users Associations in Campbell County. City of Gillette mixes Fort Union Formation water with that from the Madison and Fox Hills/Lance system for municipal / public water supply. Total of 5285 Coal Bed Methane wells permitted with WSEO in planning area as of 12/31/00. Maximum, minimum and mean depths and range of actual yields listed on permits were 138 -5507 (mean 772) feet below ground surface (bgs), and 1 - 120 (mean 27) gpm respectively. Range of depths to main water bearing zone listed on WSEO Permits were 124 - 1558 (mean 124) feet bgs. BLM Wyodak EIS assumed average expected water production to be 12 gpm over the estimated 12 year life of each CBM well (USDI,BLM, 1999). BLM Wyodak Drainage EA assumed average water production for each CBM well to be 11.1 gpm (USDI,BLM, 2000).

Fox Hills/Lance Aquifer System Lance Formation 500-1000
(North)
1600-3000
(South)
Sandstone, fine- to medium-grained, lenticular, interbedded with sandy siltstone and claystone. Yields up to 350 gpm but with large drawdowns and long well completion intervals. Locally flowing wells exist. Specific capacity, 0.05-2 gpm/ft; permeability, 6-35 gpd/ft2; transmissivity, 170-2100 gpd/ft. TDS content in waters at Foxhills/Lance System outcrops north of Niobrara County range from 600 - 1,500 mg/l, and in Niobrara County range from 1,000 - 3,300 mg/l. Composition mainly Sodium - Bicarbonate - Sulfate. Fluoride enrichment is characteristic of Fox Hills/Lance Formation waters. Possible high Sodium, and radionuclide content could be of concern in some areas. Lance Formation historical source for municipal / public, domestic and stock supply. Generally yields less than 20 gpm, but yields of several hundred gallons per minute may be possible from complete section of the formation. (Hodson, Pearl and Druse, 1973) High Fluoride content is of concern for development as source for municipal / public water systems.

Fox Hills Sandstone 150-200
(North)
400-700
(South)
Sandstone, fine-to medium-grained, interbedded with shale and siltstone. Yields up to 705 gpm but with large drawdowns and long well completion intervals. Locally flowing wells exist. Specific capacity, 0.05-2 gpm/ft; permeability, 34 gpd/ft2; transmissivity, 76-1600 gpd/ft for wells also completed in Lance. Similar to Lance Formation Historical source for municipal / public, industrial, domestic and stock supply. Tested yields of Gillette municipal / public supply wells have ranged from 85 to 705 gpm (Wester-Wetstein and Associates, Inc., 1994). High Fluoride content is of concern for development as source for municipal / public water systems. Has been used for oil well water flooding operations. Water level data available from one observation well completed in the aquifer south east of Gillette in Campbell County (49-70-31bbb01) has shown approximately 50 feet decline since 1983 (USGS, 2001).

Dakota Aquifer System Newcastle Sandstone 0-60
(Northeastern Basin)
0-100
(Southeastern Basin)
Sandstone, fine-to medium-grained, locally conglomeratic, lenticular, with interbedded siltstone, shale and claystone. Minor unit of Dakota Aquifer System exploited near outcrop only; often excessive pumping lift. Oil field data: porosity, 5-27%; permeability, <11 gpd/ft2; transmissivity, 0-140 gpd/ft. Waters at Dakota System outcrop generally contain over 1,000 mg/l TDS. TDS content 180 - 3200 mg/l in 17 samples in Weston County (Larson, 1984). Composition changes basinward from Calcium - Magnesium - Sulfate at outcrop to Sodium - Sulfate, to Sodium - Bicarbonate. Deep Basin waters > 10,00 mg/l TDS & are enriched to Sodium - Chloride. Possible high Fluoride, Selenium and radionuclide content could be of concern in some areas. Dakota Aquifer System historical source for domestic and stock use. Few reported wells in northern Black Hills (1958) due to excessive drilling depths except in outcrop areas. Yields typically adequate for stock and domestic purposes. Historically, wells typically have been completed in both the Lakota and Fall River Formations to obtain maximum production. (Whitcomb, Morris, Gordon & Robinove, 1958) Water level data available from one observation well completed in the aquifer (Lakota Formation) northeast of Lusk in Niobrara County (36-62-28ab02) has shown approximately 23 feet decline between 1974 and 2000 (USGS, 2001).

Fall River Formation 95-150
(Northeastern Basin)
35-85
(Southeastern Basin)
Sandstone, fine-to coarse-grained with interbedded shale and siltstone. Flowing yield 1-10 gpm; wells often also completed in Lakota Formation. Specific capacity, <0.5 gpm/ft. Oil field data: porosity, 11-23%; permeability, 0-36 gpd/ft2 ; transmissivity, 1-900 gpd/ft.

Lakota Formation 45-300
(Northeastern Basin)
115-200
(Southeastern Basin)
Sandstone, fine-to coarse-grained, in places conglomeratic, very lenticular, irregularly interbedded with shale which becomes dominant at top (Fuson Shale). Flowing yield 1-10 gpm, up to 150 gpm. Water well data: specific capacity, 0.01-1.4 gpm/ft; permeability, 2-14 gpd/ft2 transmissivity, 220-810 gpd/ft for 2 wells also in Fall River.

Madison Aquifer System Minnelusa Formation
(Hartville Formation)^D 600-800
(Northeastern Basin)
1000±
(Southeastern Basin)
Sandstone, fine-to coarse-grained, interbedded with limestone, dolomite, and shale, locally gypsiferous, especially at top. Upper part has historically been considered part of Madison Aquifer System, middle is aquitard, lower is minor aquifer in hydraulic connection with Madison. Flowing yields of over 200 gpm possible; specific capacity, 1-5 gpm/ft. Oil field data: porosity, 6-25%; permeability, <0.1-18 gpd/ft2; transmissivity, 2-900 gpd/ft. Similar to Madison Formation Waters at Outcrop (TDS < 600mg/l, predominantly Calcium - Magnesium - Bicarbonate type water). TDS content 230 - 2450 mg/l from 26 samples in Crook County with median and mean of 520 and 773 mg/l respectively (Larson, 1984). Some east basin waters near outcrops show TDS up to 3,000 mg/l (Calcium & Sulfate enrichment). Deep basin waters TDS > 10,000 mg/l (mainly Sodium - Chloride type water). Fluoride enrichment characteristic of Madison System waters throughout the basin. Concentrations of radionuclides could be of concern in some areas. Historical source for municipal / public water supply, domestic and stock use. Large quantities of water produced from flowing wells at Huelett (1958). Generally deeply buried (> 600 - 700 feet minimum) in area (northern Black Hills - 1958), (Whitcomb, Morris, Gordon & Robinove, 1958). Subject of USGS investigation with Pahasapa / Madison Limestone (Ogle, 2001). Water level data available from one observation well located in Crook (44-62-36-cbb02) and one in Niobrara (36-62-28-bbd01) Counties. Water levels have risen about 2 feet (since 1998) and 15 feet (since 1995) respectively in the two observation wells (USGS, 2001).

Pahasapa Limestone
(Madison Limestone)^D 550-990
(Northeastern Basin)
250±
(Southeastern Basin)
Massive fine-grained limestone and dolomitic limestone, locally cherty or cavernous. Principal unit of Madison Aquifer System. Flowing or pumped yields up to 1000 gpm; specific capacity, 0.5-50+ gpm/ft, flow-dependent; transmissivity, 1000-60,000 gpd/ft locally to 300,000 gpd/ft+. Waters at Outcrop (TDS < 600mg/l, predominantly Calcium - Magnesium - Bicarbonate type water). TDS increase basinward to > 3,000 mg/l, Sodium - Sulfate - Chloride predominating. Fluoride enrichment characteristic of Madison System waters throughout the basin. Concentrations of radionuclides could be of concern in some areas. Probably most important high yield aquifer in Wyoming. Historical source for municipal / public water supply, industrial, irrigation and stock use. Several fish hatcheries use Pahasapa / Madison aquifer as water source. Base flow and spring discharge from the Pahasapa / Madison aquifer form part of the surface run-off in the Black Hills area. (Ogle, 2001) Tested pumping rate of seven City of Gillette Pahasapa / Madison aquifer wells ranged from 535 to 900 gpm (Wester-Wetstein and Associates, Inc., 1994). Subject of USGS investigation with the Minnelusa Formation (Ogle, 2001). Water level data available from nine observation wells located in Crook (56-67-28-aab01), (56-67-28-aab02), (53-65-18bbd02), (52-63-25-dcd01), (49-62-36-cbb01), Weston (48-65-35ccb01), (46-66-25dbb01), (44-63-26cac01), and Niobrara (36-62-28-ab01) Counties. Water levels have generally risen from 13 to 40 feet in some of the observation wells since 1995 (USGS, 2001). Total estimated recharge to the Madison Limestone in the Powder River Basin in 1973 was about 75,000 acre feet/year (WSEO, 1976).

Englewood Limestone
(Gurnsey Formation, part)^D 30-60
(Northeastern Basin)
0-50±
(Southeastern Basin)
Thin-bedded limestone, locally shaley. Minor unit of Madison Aquifer System; USGS test: porosity, 15-18%; permeability, <0.1 gpd/ft2.

Generally no ground water development in area (Northern Black Hills - 1958). Formations may contain some water in permeable zones, but are generally considered to be too deeply bured to be considered important aquifers. (Whitcomb, Morris, Gordon & Robinove, 1958)

Whitewood Dolomite 50-60
(Northeastern Basin)
absent
(Southeastern Basin)
Massive bedded dolomite, locally cherty. Minor unit of Madison Aquifer System; the few existing wells also produce from the Madison aquifer. USGS test: porosity, 10-25%; specific capacity, 15 gpm/ft; permeability, <0.1-11 gpd/ft2; transmissivity, 6400 gpd/ft.

^AReported yields may reflect development needs rather than aquifer capability; higher yields can sometimes be expected, with corresponding drawdown increases. Reported water well transmissivities or permeabilities may be for wells completed in two aquifer
^BOilfield (and USGS test) data are variously derived resulting in internal inconsistencies in this compilation. Permeabilities are measured on cores or derived from other data and transmissivities are from drill stem tests or calculated from permeability.
^CActual development potential will require site specific office and field investigations to define aquifer capability and constraints unique to each project and site.
^DNomenclature for equivalent strata exposed in the Hartville uplift on the southeastern basin flank (Feathers, Libra, Stephenson and Eisen, 1981).

Taken from: Feathers, Libra, Stephenson and Eisen, 1981, Occurrence and Characteristics of Groundwater in the Powder River Basin, Wyoming

click to enlarge

Ground Water Monitoring Programs

Existing ground water monitoring programs will continue to be important in monitoring the status of ground water in the PRSB and the planning area for all activities. One such program is the Wyoming statewide USGS cooperative program operated in conjunction with the SEO and other state, county, municipal and federal agencies.

The Gillette Area Groundwater Monitoring Organization (GAGMO) and the recently formed (April 1999) Powder River Basin Area Groundwater Monitoring Organization (PRAGMO) are for coal mining and coalbed methane development. GAGMO is operated by the coal mining industry and PRAGMO by the coalbed methane development operators. These programs provide a common database that satisfy federal and state agency requirements for the respective industries to track and evaluate impacts of their operations on ground water in the PRSB.

Other state and federal agencies have their own monitoring programs associated with their management and regulatory responsibilities. State agencies include SEO, Oil and Gas Conservation Commission and the Department of Environmental Quality. Federal agencies include the Bureau of Land Management and the Forest Service.

Agricultural, Municipal, Industrial and Misc., Domestic and Stock Uses and Ground Water

Out of total of 15,793 active ground water permits inventoried in December 31, 2000 for the Basin Plan, 10,508 of the permits were for WWDC categories other than coalbed methane development.

Reported well depths for the 111 permitted active agricultural wells with production rates greater than 49 gpm ranged from 12 to 4,361 feet and averaged 511 feet. Depths to the top of the "main water bearing zones" in the permit data ranged from 5 to 3,346 feet and averaged 374 feet. The reported "actual yields" of these wells according to the permit data files ranged from 50 to 1,600 gpm and averaged 523 gpm.

There were a total of 76 permitted active municipal wells reported, with production rates greater than 49 gpm. Well depths ranged from 33 to 8,509 feet and averaged 2,056 feet. Depths to the top of the "main water bearing zones" ranged from 21 to 3,220 feet and averaged 1,320 feet. Reported "actual yields" of these wells ranged from 55 to 1,400 gpm and averaged about 324 gpm.

Permitted active industrial and miscellaneous wells with production rates greater than 49 gpm totaled 608. Well depths ranged from 5 to 10,778 feet and averaged 1,748 feet. Depths to the top of the "main water bearing zones" ranged from 5 to 8,430 feet and averaged 1,484 feet. Reported "actual yields" of these wells ranged from 50 to 3,500 gpm and averaged about 240 gpm.

A total of 2,760 permitted domestic wells were reported in the data for the planning area. Domestic well depths ranged from 1 to 10,480 feet and averaged 307 feet. Depths to the top of the "main water bearing zones" ranged from 1 to 6,170 feet and averaged 302 feet. "Actual yields" of these wells ranged from 1 to 1,325 gpm and averaged about 18 gpm.

A total of 6,756 permitted stock wells were reported in the data for the planning area. Stock well depths ranged from 1 to 1,600 feet and averaged 31 feet. Depths to the top of the "main water bearing zones" ranged from 1 to 4,194 feet and averaged 270 feet. "Actual yields" of these wells ranged from 1 to 1,600 gpm and averaged about 14 gpm.

As previously noted, the relative importance of each of the aquifer systems to the various categories of use is summarized in Table III-24. This information together with the maps provided in the "Available Ground Water Determination" technical memorandum, can be used to make further inferences at an initial level, of the relative importance of each of the aquifer systems with respect to the five non-coalbed methane uses.

Impacts on Ground Water and Surface Water Supplies

Impacts to ground water will depend on local geologic and hydrologic conditions in the areas of development. Possible impacts to ground water could include:

The possible depletion of surface water that is interconnected with aquifer systems. The principal aquifer systems of concern with respect to this impact include the Madison and the Quaternary Alluvial Aquifer Systems. The geographic areas of concern with respect to the Madison Aquifer System, are along the northeastern part of the planning area where streams flow across Madison System outcrops. The areas of concern with respect to the Quaternary Alluvial Aquifer System, are throughout the entire planning area in the alluvium adjacent to surface water systems.
Ground water development in any of these areas, irrespective of proposed use, will require detailed investigations that also address the possibility and degree of surface and ground water interconnection. Depending on proposed ground water use, the existing SEO permitting process should be able to address the issue. The Wyoming Department of Environmental Quality, Water Quality Division (WDEQ/WQD) might also be involved in the permitting process with respect to surface / ground water interconnection under provisions of the USEPA Safe Drinking Water Act (Ground Water Under the Direct Influence of Surface Water).
Depending on location, geologic source, and water demand requirements, there is the possibility that domestic and stock well densities could create interference problems between wells and/or aquifer depletion problems. This is probably more of a probability in areas experiencing rural development of single family residences and/or multi-family subdivisions where individual or community public water supply wells provide water. The SEO permitting process for ground water has historically addressed these issues.
New legislation would be required to establish ground water control zones for any ground water use other than agricultural use experiencing declining water levels or aquifer depletion problems (such as use of aquifers of the Fort Union Formation in the Gillette area for public and domestic water sources). The potential problem in conjunction with coalbed methane development has also been recognized (depletion of aquifers and wells), and responsible state and federal agencies are attempting to address related ground water impacts.
There is the possibility of aquifer systems being impacted due to oil and gas operations. The nature of these impacts would depend on the geographic as well as the geologic and stratigraphic location of the activity. A potential impact could involve aquifer depletion if water were used from one of the aquifer systems for secondary recovery operations (such as the Fox Hills Sandstone of the Fox Hills/Lance Aquifer System). Other impacts could be water quality related through drilling and recovery operations and leakage through inadequate and/or failed plugging and abandonment of production wells. The possibility of these impacts and other issues should be able to be addressed by existing regulatory activity and programs of the Wyoming Oil and Gas Conservation Commission, Wyoming Department of Environmental Quality and the SEO.
The Wyoming Department of Environmental Quality, Water Quality Division (WDEQ/WQD) is initiating a Source Water Assessment and Protection Program in 2002 for participating Public Water Systems throughout the state. This program should address issues regarding the safeguarding of aquifers for water quality considerations in areas where public water systems are located.

Coalbed Methane Development and Ground Water

For ease of reference, the main coal seam that is the target of coalbed methane development in the PRSB and within the planning area is referred to as the Wyodak-Anderson coal zone. Methane gas is trapped in micropores and cleat fracture systems within the coal, and is maintained in that state by the natural pressure of ground water. The gas is extracted using wells that are drilled and completed in the coal to remove water and lower the water pressure responsible for holding the gas. The gas moves out of the coal as the water pressure is lowered, and is recovered from the well along with the water.

As previously noted, a total of 6,657 coalbed methane wells were identified in the SEO data query for the Basin Plan. Reported well depths ranged from 29 to 5507 feet and averaged 789 feet. Reported depths to the top of the "main water bearing zones" in the permit data ranged from 78 to 1604 feet and averaged 709 feet. Reported "actual yields" of coalbed methane wells in the permit data files ranged from 0.1 to 200 gpm and averaged 31 gpm.

The BLM has recently used 12 gpm (USDI, 1999, Wyodak Coalbed Methane Project Final Environmental Impact Statement) and 11.1 gpm (USDI, 2000, Wyodak Drainage Coalbed Methane Environmental Assessment) for average production rates of coalbed methane wells in the preparation of environmental impact statements for coalbed methane development within the planning area. The actual ground water production rate will probably be variable throughout the life of each well. As an example, the BLM projected the initial ground water production rates of the wells for the Lighthouse Coalbed Methane Project to be 11 gpm, with an interim average of 7 gpm, and a final rate of less than 3 gpm per well (USDI, 1995, Lighthouse Coalbed Methane Project Environmental Assessment).

The USGS, in cooperation with the BLM and coalbed methane production companies, is conducting multidisciplinary studies in the PRSB in an effort to provide a better understanding of coalbed methane resources and associated water. A USGS report for one of the studies in progress provides preliminary compositional data on water from 47 coalbed methane wells sampled between June, 1999 and May, 2000. Water co-produced with coalbed methane is generally a sodium bicarbonate type. Of the 47 wells sampled by USGS, 32 were located within the planning area and 15 were within the Powder/Tongue River Basin Plan Area. Total dissolved solids content (TDS) of all 47 samples ranged from 270 to 2010 and averaged 850 mg/l. Values of the sodium adsorption ratio ((SAR), which is a relative measure of the suitability of water for irrigation due to sodium content) for the 47 samples ranged from 5.7 to 32 and averaged 12. For comparison, an SAR of roughly 13 would generally be considered the upper limit for field crops in clayey soils.

TDS and SAR of the 32 samples from coalbed methane wells in the planning area ranged from 270 to 1170 (mean 653 mg/l) and 5.7 to 12 (mean 7.85), respectively. TDS and SAR of the 15 samples from coalbed methane wells in the Powder/Tongue River Basin Plan Area ranged from 540 to 2010 (mean 1309 mg/l) and 7.7 to 32 (mean 19.82) respectively. The results of the USGS samples indicated that TDS and SAR of waters in the Wyodak-Anderson coal zone generally increase in the PRSB from south to north and from east to west.

Concentrations of most of the 17 trace elements analyzed by USGS in samples of water from the 47 coalbed methane wells were below detection limits. All of the concentrations for the 17 trace elements were below the maximum contaminant levels of the Primary Drinking Water Standards of the USEPA. The USGS reported that there were no noticeable trends in trace element concentrations in the samples from the 47 wells.

Impacts on Ground Water and Surface Water Supplies

Potential impacts to ground and surface water have been identified by BLM in the preparation of environmental assessments (EA) and environmental impact statements (EIS) for numerous coalbed methane projects in the PRSB within the planning area. Impacts to ground water will depend on local geologic and hydrologic conditions in the areas of coalbed methane development. Possible impacts to ground water that have been identified include:

The dewatering of aquifers and the lowering of water levels and yields in production wells located in the vicinity of coalbed methane development. This includes wells that are completed in the Wyodak-Anderson coal zone and any aquifers that may be in hydraulic connection with the coal. Ground water modeling performed in association with the Wyodak coalbed methane Project EIS, predicted a fairly rapid recovery of water levels within a period of three to four years to within 20 or 30 feet of preoperational conditions at the cessation of coalbed methane operations. This estimate was based on the projected redistribution of the large amount of ground water in storage within the coal west, north, and south of the development. Total recovery was projected to take a very long time as recharge to the coal aquifer would be needed to replace that ground water removed from storage during coalbed methane operations.
Possible methane seepage into wells and structures in the proximity of coalbed methane development that could pose a health and safety hazard to planning area residents.
Possible increased infiltration of water from coalbed methane production into shallow alluvial ground water systems in the Gillette area that could aggravate subsurface structure problems.
Possible increased infiltration of water from coalbed methane production into shallow ground water systems in the planning area that could impact the quality and use of ground water from shallow systems.
Possible impacts to surface coal mining operations.
Possible impacts to the in-situ leach extraction process of uranium mining in the southwest portion of the planning area.

Possible surface water related impacts that have been identified could include:

Possible change in the drainage characteristics in draws and drainages from ephemeral to perennial. This could result in an increase in the erosion potential and sedimentation problems in receiving drainages. Coalbed methane generated water could result in increased flooding potential in receiving drainages. Higher flows could also impede landowner access to perform normal work associated with their operations.
A possible alteration of the chemical characteristics of receiving surface waters due to coalbed methane generated water. This could include a change due to increased salinity and sodium content that could impact irrigation practices and the utilization of surface water for irrigation. Concern has also been expressed on the impacts of coalbed methane water on possible toxicity problems and aquatic habitats in receiving waters.

A more comprehensive discussion of impacts associated to coalbed methane development is available in the previously mentioned EAs and EISs prepared by BLM.

Future Development

The geology, drilling depths, hydrogeologic characteristics and ground water quality of aquifer systems differ throughout the planning area. All of the aquifer systems in the planning area previously discussed probably have some potential for development. Site specific investigations in conjunction with experience and common sense will be required to determine the opportunities available to develop ground water with wells of sufficient capacity for a specific use within the planning area.

Although there have been considerable investigations in the PRSB within the planning area, there have been few regional assessments of the annual recharge, storage and sustained yield capability of the major aquifer systems both in the PRSB and the planning area. General conclusions regarding ground water development potential of four of the six major aquifer systems in the planning area discussed in this report are summarized below:

The Madison Aquifer System may have the most development potential for high yield wells on a sustained basis within the planning area. Previous investigations have estimated that annual average recharge to this system is approximately 75,000 acre feet per year within the entire PRSB in northeast Wyoming. Drilling depths and water quality may constrain development at specific locations within the planning area.
The Fox Hills/Lance Aquifer System may have local potential for development of wells with low to moderate yields. The possible high fluoride content in water from this system might influence the desirability of use for a municipal/public supply without provision for treatment or special management, such as mixing with water from other sources. Wells completed in the Fox Hills/Lance Aquifer System may offer an alternative source to wells completed in the Fort Union/Wasatch Aquifer System impacted by coalbed methane development.
The Fort Union/Wasatch Aquifer System is utilized for most uses in the PRSB within the planning area. The Wyodak-Anderson coal aquifer and hydraulically interconnected aquifers of the Aquifer System will be heavily impacted by ground water withdrawals in near coalbed methane development. The water co-produced with coalbed methane may provide an opportunity for utilization, depending on location, quality and nature of potential use. Further consideration of injection of water co-produced with coalbed methane development into the Fox Hills/Lance and Fort Union/Wasatch Aquifer Systems is warranted in the planning area.
Aquifers in the Alluvial Aquifer (Quaternary Aquifer) System within the planning area may have local development potential for wells with moderate yields if induced infiltration of surface water can be tolerated.

Table III-24 summarizes the development potential of the above units and also the Dakota Aquifer System and the Middle Tertiary Aquifer (Arikaree Formation) in the planning area. Items of interest related to ground water availability/development potential are also summarized in Table III-24. These items include the general lithologic and hydrologic character of the aquifer systems in addition to the general quality of ground water available from the systems.

Wyoming State Water Plan

Wyoming State Water Plan

Northeast Wyoming River Basins Water Plan
Final Report

III Available Surface Water and Ground Water Determination

Basin	Station Number	Station Name	Natural Flow	Period of Record in Water Years **	Note
Cheyenne	06364700	Antelope Creek Near Teckla, WY	NO	1978-1981
	06365300	Dry Fork Cheyenne River Near Bill, WY	NO	1977-1981, 1986-1987
	0635900	Cheyenne River Near Dull Center, WY	NO	1976-1981, 1986-1987
	06375600	Little Thunder Chreek Near Hampshire, WY	NO	1978-1981, 1988-1998
	06376300	Black Thunder Creek Near Hampshire, WY	NO	1973-1990
	06378300	Lodgepole Creek Near Hampshire, WY	NO	1978-1981
	06379600	Box Creek Near Bill, WY	YES	1956-1958
	06386000	Lance Creek Near Riverview, WY	NO	1948-1954, 1956-1983
	06386500	Cheyenne River Near Spencer, WY	NO	1949-1974
	06392900	Beaver Creek at Mallo Camp, Near Four Corners, WY	YES	1975-1982, 1991-current
	06392950	Stockade Beaver Creek Near Newcastle, WY	NO	1975-1982, 1991-current
	06394000	Beaver Creek Near Newcastle, WY	NO	1945-1998
	06394500	Beaver Creek Near Burdock, SD	NO	1905-1907, 1929-1932	Abt. 2 mi. into SD
	06395000	Cheyenne River at Edgemont, SD	NO	1903-1907, 1928-1933, 1947-	Several Miles into SD; No winter records 1903-1906
Belle Fourche	06425720	Belle Fourche River Below Rattlesnake Creek, Near Piney, WY	NO	1976-1983
	06425750	Coal Creek Near Piney, WY	YES	1981-1983
	06425780	Belle Fourche River Above Dry Creek Near Piney, WY	NO	1976-1983
	06425900	Caballo Creek at Mouth Near Piney, WY, WY	NO	1977-1983
	06425950	Raven Creek Near Moorcroft, WY	YES	1977-1983
	06426000	Belle Fourche River Near Moorcroft, WY, WY	NO	1923-1933
	06426100	Stonepile Creek at Gillette, WY	YES	1988-1992	No Winter records; Adjusted for diversions using Burlington Lake Ditch
	06426400	Donkey Creek Near Moorcroft, WY	NO	1977-1981
	06426500	Belle Fourche River Below Moorcroft, WY	NO	1943-1970, 1976-1983, 1986-1987, 1991-current
	USBR Gage	Inflow to Keyhole Reservoir	NO	USBR: 1952-current	Adjusted for evaporation
	USBR Gage	Belle Fourche - Keyhole Reservoir Releases	NO	USBR: 1952-current
	06427500	Belle Fourche River Below Keyhole Reservoir, WY	NO	1951-1995
	06428000	Belle Fourche River at Hulette, WY	NO	1929-1933, 1938-1952
	06428200	Belle Fourche River Near Alva, WY	NO	1989-1998	No winter records
	06428500	Belle Fourche River at Wyoming-South Dakota State Line	NO	1947-current
	06429500	Cold Springs Creek at Buckhorn, WY	YES	1975-1982, 1991-current
	06429900	Sand Creek at Ranch A Near Beulah, WY	YES	1975-1976	Combined with Station 06429905
	06429905	Sand Creek Near Ranch A Near Beulah, WY	YES	1976-1983, 1991-current
	06430500	Redwater Creek at Wyoming-South Dakota State Line, WY	NO	1929-1931, 1936-1937, 1954-	Adjusted for diversion using Murrey Ditch
Niobrara	06454000	Niobrara River at Wyoming-Nebraska State Line, WY	NO	1956-1994

Basin	Station Name	Estimated Average Streamflow for 1970-1999 in Acre-Feet
Basin	Station Name	Oct	Nov	Dec	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Annual
Cheyenne	Willow Creek at Mouth in Section 28, T38N, R72W	9	0	0	3	76	238	4	109	3	10	18	0	470
	Woody Creek at Mouth in Section 5, T39N, R69W	1	0	0	0	10	31	0	14	0	1	2	0	59
	Lake Creek at Mouth in Section 30, T40N, R68W	3	0	0	1	23	72	1	33	1	3	5	0	142
	Sheep Creek at Mouth in Section 7, T40N, R67W	1	0	0	0	7	23	0	11	0	1	2	0	45
	Wagonhound Creek at Mouth in Section 31, T41N, R67W	2	0	0	1	15	48	1	22	1	2	4	0	96
	Snyder Creek at Mouth in Section 23, T40N, R64W	8	0	0	3	71	223	3	103	3	10	17	0	441
	Boggy Creek at Mouth in Section 32, T40N, R63W	2	0	0	1	20	61	1	28	1	3	5	0	122
	Sevenmile Creek at Mouth in Section 34, T40N, R63W	1	0	0	0	10	30	0	14	0	1	2	0	58
	Mule Creek at Mouth in Section 6, T39N, R61W	4	0	0	1	31	96	1	44	1	4	7	0	189
	Robbers' Roost Creek at Mouth in Section 23, T40N, R61W	5	0	0	2	43	136	2	63	2	6	10	0	269
	Beaver Creek Just Below Mush Creek in Section 32, T44N, R62W	33	0	0	10	292	1,187	15	546	16	51	77	0	2,227¹
	Oil Creek at Mouth in Section 26, T43N, R62W	346	0	0	61	3,958	6,405	377	2,930	87	275	2,425	0	16,864
	Blacktail Creek at Mouth in Section 2, T41N, R61W	200	195	193	186	163	188	191	293	262	240	215	198	2,524
	Dry Beaver Creek at Mouth in Section 4, T47N, R60W	107	99	97	92	95	111	133	136	141	130	118	107	1,366
Belle Fourche	Dry Creek at Mouth in Section 29, T47N, R70W	2	0	0	1	14	43	1	20	1	2	3	0	87
	Yellow Hammer Creek at Mouth in Section 10, T47N, R70W	1	0	0	0	5	16	0	7	0	1	1	0	31
	Whitetail Creek at Mouth in Section 32, T48N, R69W	1	0	0	0	8	24	0	11	0	1	2	0	47
	Four Horse Creek at Mouth in Section 11, T48N, R69W	8	0	0	3	73	228	4	105	3	10	17	0	451
	Timber Creek at Mouth in Section 2, T48N, R69W	2	0	0	1	19	60	1	27	1	3	5	0	119
	Buffalo Creek at Mouth in Section 14, T49N, R68W	11	0	0	3	93	290	4	133	4	12	22	0	572
	Donkey Creek Just Upsteam of Gage in Sec. 30, T50N, R68W	0	0	0	413	1,135	3,278	1,555	4,005	946	0	0	0	11,332¹
	Trail Creek at Mouth in Section 24, T50N, R68W	1	0	0	0	10	32	0	15	0	1	2	0	61
	Dry Creek at Mouth in Section 24, T50N, R68W	2	0	0	1	14	45	1	21	1	2	3	0	90
	Robinson Creek at Mouth in Section 18, T50N, R67W	1	0	0	0	4	14	0	6	0	1	1	0	27
	Duck Creek at Mouth in Section 8, T50N, R67W	5	0	0	4	59	115	4	53	2	5	24	0	271
	Miller Creek at Mouth in Section 9, T50N, R67W	58	0	0	41	672	1,314	44	604	18	57	271	0	3,079
	Smoke Creek at Mouth in Section 9, T50N, R67W	1	0	0	1	17	34	1	16	0	1	7	0	78
	Berger Creek at Mouth in Section 12, T50N, R67W	2	0	0	2	28	56	2	26	1	2	11	0	130
	Lone Tree Creek at Mouth in Section 26, T51N, R67W	5	0	0	4	62	121	4	55	2	5	25	0	283
	Wind Creek at Mouth in Section 13, T50N, R67W	133	0	0	93	1,539	3,008	101	1,382	41	129	620	0	7,046
	Deer Creek at Mouth in Section 23, T51N, R67W	28	0	0	20	325	635	21	292	9	27	131	0	1,488
	Eggie Creek at Mouth in Section 21, T51N, R66W	4	0	0	3	45	88	3	40	1	4	18	0	206
	Mule Creek at Mouth in Section 15, T50N, R66W	17	0	0	12	197	385	13	177	5	17	79	0	902
	Cottonwood Creek at Mouth in Section 35, T51N, R66W	5	0	0	3	52	102	3	47	1	4	21	0	238
	Arch Creek at Mouth in Section 11, T51N, R66W	7	0	0	2	62	195	3	90	3	8	15	0	385
	Inyan Kara Creek at Mouth in Section 25, T52N, R66W	1,154	1,142	1,122	1,083	1,028	1,311	1,128	1,750	1,553	1,319	1,310	1,165	15,065
	Cabin Creek at Mouth in Section 14, T52N, R66W	5	0	0	2	47	148	2	68	2	6	11	0	291
	Miller Creek at Mouth in Section 12, T52N, R66W	5	0	0	1	39	122	2	56	2	5	9	0	241
	Lytle Creek at Mouth in Section 8, T53N, R65W	3	0	0	1	27	84	1	39	1	4	6	0	166
	Whitetail Creek at Mouth in Section 14, T54N, R65W	83	82	81	78	69	77	81	118	112	94	93	84	1,052
	Blacktail Creek at Mouth in Section 12, T54N, R65W	210	209	205	198	175	197	206	301	284	240	237	213	2,675
	Beaver Creek at Mouth in Section 1, T55N, R64W	459	457	449	433	382	431	451	658	621	524	518	467	5,850
	East Creek at Mouth in Section 32, T55N, R63W	48	48	47	45	40	45	47	68	65	55	54	49	611
	Arnold Creek at Mouth in Section 28, T55N, R63W	22	22	22	21	18	21	22	32	30	25	25	23	283
	Horse Creek at Mouth in Section 19, T56N, R61W	76	75	74	71	63	71	74	108	102	86	85	77	962
	Pine Creek at Mouth in Section 33, T56N, R61W	172	171	168	162	143	161	169	247	233	197	194	175	2,192
	Kilpatrick Creek at Mouth in Section 3, T55N, R61W	69	69	68	65	58	65	68	99	94	79	78	70	882
	Kruger Creek at Mouth in Section 11, T55N, R61W	34	34	33	32	28	32	33	48	46	39	38	34	431
	Oak Creek at Mouth in Section 20, T55N, R60W	216	215	211	203	179	202	212	309	292	247	243	219	2,748
	South Redwater Creek Just Above Sand Creek in Section 31, T53N, R60W	565	563	553	533	470	530	555	810	765	646	637	575	7,202
	Redwater Creek Just Above South Redwater Creek in Section 31, T53N, R60W	287	286	281	271	239	269	282	411	388	328	324	292	3,658

Reach	Reach Name	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
1	Sand Creek ¹	484	478	643	865	1,808	2,087	1,381	1,382	946	495	347	247	10,680
2	South Redwater Creek	632	588	701	762	1,158	1,192	833	862	672	689	688	663	8,808
3	S Redwater Cr below Sand Cr	2,137	1,980	2,341	2,586	4,108	4,374	2,946	2,981	2,558	2,308	2,236	2,190	30,607
4	Redwater Creek	321	299	356	365	504	398	159	204	172	338	331	327	3,453
5	Redwater Cr beow S Redwater Cr	2,498	2,317	2,718	3,012	4,712	4,772	3,104	3,185	2,730	2,646	2,567	2,517	34,279

Subbasin	Hydrologic Condition
Subbasin	Wet Years	Normal Years	Dry Years
Redwater Creek	34,000	26,000	17,000
Beaver Creek	30,000	20,000	14,000
Cheyenne River	103,000	31,000	5,000
Belle Fourche River	151,000	71,000	13,000

Hydrologic Condition	Average Annual Apportionment (AF)
Hydrologic Condition	Belle Fourche River	Redwater Creek	Total
Wet Years	15,600	3,300	18,900
Normal Years	7,400	2,400	9,800
Dry Years	1,100	1,400	2,500

Major Aquifer System	Geologic Unit	Thickness (Feet)	Lithologic Character	Hydrological Character^A,B	General Water Quality	Availability/Development Potential^C	Remarks
Quaternary Alluvial Aquifer System	Alluvium and Terrace Deposits	0-100+	Clay rich sandy silt, silt, sand and gravel; unconsolidated and interbedded; present along most streams. Thickness generally less than 50 feet but may be thicker. Coarser deposits in valleys of the Belle Fourche and the Cheyenne Rivers. Alluvium overlying formations of Tertiary age is generally fine to medium grained in central part of basin. (Hodson, Pearl and Druse, 1971)	Yield of 1000 gpm possible, often through induced recharge. Terraces topographically high and often drained. Specific capacity, 0.3-18 gpm/ft; porosity, 28-45%; permeability, 0.1-1100 gpd/ft2; transmissivity, 15-64000 gpd/ft; specific yield, 2-39%. Coarser deposits have better aquifer properties.	TDS content generally range from about 100 to >4000 mg/l, and chemical characteristics of water differ geographically. Chemical type and mineralization of the water can be expected to vary depending on underlying rock types and the nature and degree of interconnection with underlying bedrock aquifers as well as surface water. Moderate to high mineralization tolerable for stock and domestic use. Suitability for irrigation generally limited to salt tolerant crops. Water in the alluvium in Black Hills generally is better quality than central part of basin (Hodson, Pearl and Druse, 1971).	Historical source for domestic and stock use. Production has ranged from 1 to 900 gpm. Ground water development potential generally better in coarse-grained deposits and poorer in fine-grained materials. Yields in the high end of the above range might be possible to optimally located and properly designed wells if induced infiltration from surface water can be tolerated (Belle Fourche, Cheyenne and Niobrara River Basins). Potential source for irrigation, municipal / public and industrial sources where more than 40 feet of saturated well sorted sand and gravel are present.	Quaternary alluvial aquifers generally in hydraulic connection with all bedrock aquifers in outcrop areas and also with surface waters. Alluvial aquifers in larger valleys provide hydraulic interconnection between otherwise hydraulically isolated bedrock aquifers (Whitcomb, 1965). Alluvial aquifers also serve as interchange point and storage for ground water in the hydrologic cycle (Davis and Rechard, 1977), (Davis, 1976). Induced recharge from surface waters is probable in areas of extensive development.
Middle Tertiary Aquifer	Arikaree Formation	0-500 (southeast only)	Tuffaceous sandstone, fine-grained with silty zones, coarse sand lenses and concretionary zones.	Yields up to 1000 gpm; specific capacity up to 232 gpm/ft; porosity, 5-24%; permeability <1-300 gpd/ft2; transmissivity up to 77,000 gpd/ft.	TDS content of water ranges from 261 to 535 mg/l. Composition mainly Calcium Bicarbonate (Whitcomb, 1965). Median TDS content in samples from 12 wells in Niobrara County 321 mg/l (Larson, 1984).	Historical source for municipal / public, industrial, domestic, stock and irrigation supply with tested production ranging as high as 195 to 730 gpm (Whitcomb, 1965). Yields of 1000 gpm might be possible to optimally located and properly designed wells.	Water level data available from two observation wells located east and south east of Lusk in Niobrara County (32-62-05-baa01), (32-62-32-bbb01). Water levels have shown approximately 6 to 13 feet decline in water levels in the aquifer since the 1970s with possibly some stabilization and slight recovery since early to mid 1990s (USGS, 2001).
Fort Union / Wasatch Aquifer System	Wasatch Formation	up to 1600	Fine- to coarse-grained lenticular sandstones interbedded with shale and coal, coarser in south.	Yields generally <15 gpm, locally flowing wells exist. Yields historically could be expected to range from 10 to 50 gpm in the north part of the basin with the possibility of higher yields up to 500 gpm in the south part of the basin (Hodson, Pearl and Druse, 1973). Specific capacity, 0.10-14 gpm/ft (Hodson, Pearl and Druse, 1973); porosity, 28-30%; permeability, 0.01-65 gpd/ft2; transmissivity, average 500 gpd/ft range 1-4000 gpd/ft.	TDS content of waters is variable and ranges from <200 to > 8000 mg/l (Hodson, Pearl and Druse, 1973). Sodium Sulfate and Sodium Bicarbonate are general dominate water types. Major ion composition varies with depth and shows more Sodium and Bicarbonate content with depth. Radium 226 + 228 may be of concern near uranium deposits.	Historical source for municipal / public, domestic and stock supply. Yields ranging from 10 to 50 gpm in the north part of the basin can be expected with the possibility of higher yields up to 500 gpm in the south part of the basin (Hodson, Pearl and Druse, 1973).	Water level data available from two observation wells located in Campbell County (50-72-21-aba01), (42-71-35-aaa01) and one observation well in Converse County (37-70-10-cbb01). Water levels in the aquifer have shown about a 40 feet rise between 1983 and 2000 in Gillette and about a 40 to 50 feet decline south east of Wright in Campbell County. Water levels in the aquifer in northwest Converse County have shown a rise of about 7 feet between 1988 and 1999 after a decline of about 6 feet between 1986 and 1988. (USGS, 2001)
Fort Union / Wasatch Aquifer System	Fort Union Formation	1100-2270	Sandstone, fine- to medium-grained, lenticular, interbedded with siltstone, coal and shale. Middle part may be shalier in north, upper part siltier in south. "Clinker" associated with coal outcrops.	Flowing yields of 1-60 gpm where confined. Pumped yields up to 250 gpm with several hundred feet of drawdown. Specific capacity, 0.1-2 gpm/ft; permeability, 0.01-100 gpd/ft2; transmissivity, 1-5000 gpd/ft. Coal and clinker generally have better aquifer properties than sandstones. Locally clinker transmissivity up to 3,000,000 gpd/ft; Anisotropy and leaky confining layers are common.	TDS content and major ion composition of Fort Union Formation Waters as above. Water co-produced with coal bed methane is predominantly Sodium Bicarbonate type with TDS content and SAR (32 samples), 270 - 1170 mg/l (mean of 653 mg/l) and 5.7 - 12 (mean of 7.85) respectively (Rice, Ellis & Bullock, 2000). BLM Wyodak EIS assumed average TDS concentration of 764 mg/l (USDI,BLM, 1999). High radionuclide content of concern in areas near uranium ore zones.	Historical source for municipal / public, domestic and stock supply. Maximum expected yields of about 130 to 150 gpm (Hodson, Pearl and Druse, 1973), (Wester -Wetstein and Associates, Inc., 1994). Exploration and development of new Fort Union well field including conjunctive use / recharge of Coal Bed Methane production water under consideration \for the City of Gillette.	Source for approximately 14 municipal and public water supply systems including the City of Gillette and adjacent Districts, Joint Powers Boards and Privately Owned Water Systems and Water Users Associations in Campbell County. City of Gillette mixes Fort Union Formation water with that from the Madison and Fox Hills/Lance system for municipal / public water supply. Total of 5285 Coal Bed Methane wells permitted with WSEO in planning area as of 12/31/00. Maximum, minimum and mean depths and range of actual yields listed on permits were 138 -5507 (mean 772) feet below ground surface (bgs), and 1 - 120 (mean 27) gpm respectively. Range of depths to main water bearing zone listed on WSEO Permits were 124 - 1558 (mean 124) feet bgs. BLM Wyodak EIS assumed average expected water production to be 12 gpm over the estimated 12 year life of each CBM well (USDI,BLM, 1999). BLM Wyodak Drainage EA assumed average water production for each CBM well to be 11.1 gpm (USDI,BLM, 2000).
Fox Hills/Lance Aquifer System	Lance Formation	500-1000 (North) 1600-3000 (South)	Sandstone, fine- to medium-grained, lenticular, interbedded with sandy siltstone and claystone.	Yields up to 350 gpm but with large drawdowns and long well completion intervals. Locally flowing wells exist. Specific capacity, 0.05-2 gpm/ft; permeability, 6-35 gpd/ft2; transmissivity, 170-2100 gpd/ft.	TDS content in waters at Foxhills/Lance System outcrops north of Niobrara County range from 600 - 1,500 mg/l, and in Niobrara County range from 1,000 - 3,300 mg/l. Composition mainly Sodium - Bicarbonate - Sulfate. Fluoride enrichment is characteristic of Fox Hills/Lance Formation waters. Possible high Sodium, and radionuclide content could be of concern in some areas.	Lance Formation historical source for municipal / public, domestic and stock supply. Generally yields less than 20 gpm, but yields of several hundred gallons per minute may be possible from complete section of the formation. (Hodson, Pearl and Druse, 1973)	High Fluoride content is of concern for development as source for municipal / public water systems.
Fox Hills/Lance Aquifer System	Fox Hills Sandstone	150-200 (North) 400-700 (South)	Sandstone, fine-to medium-grained, interbedded with shale and siltstone.	Yields up to 705 gpm but with large drawdowns and long well completion intervals. Locally flowing wells exist. Specific capacity, 0.05-2 gpm/ft; permeability, 34 gpd/ft2; transmissivity, 76-1600 gpd/ft for wells also completed in Lance.	Similar to Lance Formation	Historical source for municipal / public, industrial, domestic and stock supply. Tested yields of Gillette municipal / public supply wells have ranged from 85 to 705 gpm (Wester-Wetstein and Associates, Inc., 1994).	High Fluoride content is of concern for development as source for municipal / public water systems. Has been used for oil well water flooding operations. Water level data available from one observation well completed in the aquifer south east of Gillette in Campbell County (49-70-31bbb01) has shown approximately 50 feet decline since 1983 (USGS, 2001).
Dakota Aquifer System	Newcastle Sandstone	0-60 (Northeastern Basin) 0-100 (Southeastern Basin)	Sandstone, fine-to medium-grained, locally conglomeratic, lenticular, with interbedded siltstone, shale and claystone.	Minor unit of Dakota Aquifer System exploited near outcrop only; often excessive pumping lift. Oil field data: porosity, 5-27%; permeability, <11 gpd/ft2; transmissivity, 0-140 gpd/ft.	Waters at Dakota System outcrop generally contain over 1,000 mg/l TDS. TDS content 180 - 3200 mg/l in 17 samples in Weston County (Larson, 1984). Composition changes basinward from Calcium - Magnesium - Sulfate at outcrop to Sodium - Sulfate, to Sodium - Bicarbonate. Deep Basin waters > 10,00 mg/l TDS & are enriched to Sodium - Chloride. Possible high Fluoride, Selenium and radionuclide content could be of concern in some areas.	Dakota Aquifer System historical source for domestic and stock use.	Few reported wells in northern Black Hills (1958) due to excessive drilling depths except in outcrop areas. Yields typically adequate for stock and domestic purposes. Historically, wells typically have been completed in both the Lakota and Fall River Formations to obtain maximum production. (Whitcomb, Morris, Gordon & Robinove, 1958) Water level data available from one observation well completed in the aquifer (Lakota Formation) northeast of Lusk in Niobrara County (36-62-28ab02) has shown approximately 23 feet decline between 1974 and 2000 (USGS, 2001).
	Fall River Formation	95-150 (Northeastern Basin) 35-85 (Southeastern Basin)	Sandstone, fine-to coarse-grained with interbedded shale and siltstone.	Flowing yield 1-10 gpm; wells often also completed in Lakota Formation. Specific capacity, <0.5 gpm/ft. Oil field data: porosity, 11-23%; permeability, 0-36 gpd/ft2 ; transmissivity, 1-900 gpd/ft.
	Lakota Formation	45-300 (Northeastern Basin) 115-200 (Southeastern Basin)	Sandstone, fine-to coarse-grained, in places conglomeratic, very lenticular, irregularly interbedded with shale which becomes dominant at top (Fuson Shale).	Flowing yield 1-10 gpm, up to 150 gpm. Water well data: specific capacity, 0.01-1.4 gpm/ft; permeability, 2-14 gpd/ft2 transmissivity, 220-810 gpd/ft for 2 wells also in Fall River.
Madison Aquifer System	Minnelusa Formation (Hartville Formation)^D	600-800 (Northeastern Basin) 1000± (Southeastern Basin)	Sandstone, fine-to coarse-grained, interbedded with limestone, dolomite, and shale, locally gypsiferous, especially at top.	Upper part has historically been considered part of Madison Aquifer System, middle is aquitard, lower is minor aquifer in hydraulic connection with Madison. Flowing yields of over 200 gpm possible; specific capacity, 1-5 gpm/ft. Oil field data: porosity, 6-25%; permeability, <0.1-18 gpd/ft2; transmissivity, 2-900 gpd/ft.	Similar to Madison Formation Waters at Outcrop (TDS < 600mg/l, predominantly Calcium - Magnesium - Bicarbonate type water). TDS content 230 - 2450 mg/l from 26 samples in Crook County with median and mean of 520 and 773 mg/l respectively (Larson, 1984). Some east basin waters near outcrops show TDS up to 3,000 mg/l (Calcium & Sulfate enrichment). Deep basin waters TDS > 10,000 mg/l (mainly Sodium - Chloride type water). Fluoride enrichment characteristic of Madison System waters throughout the basin. Concentrations of radionuclides could be of concern in some areas.	Historical source for municipal / public water supply, domestic and stock use.	Large quantities of water produced from flowing wells at Huelett (1958). Generally deeply buried (> 600 - 700 feet minimum) in area (northern Black Hills - 1958), (Whitcomb, Morris, Gordon & Robinove, 1958). Subject of USGS investigation with Pahasapa / Madison Limestone (Ogle, 2001). Water level data available from one observation well located in Crook (44-62-36-cbb02) and one in Niobrara (36-62-28-bbd01) Counties. Water levels have risen about 2 feet (since 1998) and 15 feet (since 1995) respectively in the two observation wells (USGS, 2001).
	Pahasapa Limestone (Madison Limestone)^D	550-990 (Northeastern Basin) 250± (Southeastern Basin)	Massive fine-grained limestone and dolomitic limestone, locally cherty or cavernous.	Principal unit of Madison Aquifer System. Flowing or pumped yields up to 1000 gpm; specific capacity, 0.5-50+ gpm/ft, flow-dependent; transmissivity, 1000-60,000 gpd/ft locally to 300,000 gpd/ft+.	Waters at Outcrop (TDS < 600mg/l, predominantly Calcium - Magnesium - Bicarbonate type water). TDS increase basinward to > 3,000 mg/l, Sodium - Sulfate - Chloride predominating. Fluoride enrichment characteristic of Madison System waters throughout the basin. Concentrations of radionuclides could be of concern in some areas.	Probably most important high yield aquifer in Wyoming. Historical source for municipal / public water supply, industrial, irrigation and stock use. Several fish hatcheries use Pahasapa / Madison aquifer as water source. Base flow and spring discharge from the Pahasapa / Madison aquifer form part of the surface run-off in the Black Hills area. (Ogle, 2001) Tested pumping rate of seven City of Gillette Pahasapa / Madison aquifer wells ranged from 535 to 900 gpm (Wester-Wetstein and Associates, Inc., 1994).	Subject of USGS investigation with the Minnelusa Formation (Ogle, 2001). Water level data available from nine observation wells located in Crook (56-67-28-aab01), (56-67-28-aab02), (53-65-18bbd02), (52-63-25-dcd01), (49-62-36-cbb01), Weston (48-65-35ccb01), (46-66-25dbb01), (44-63-26cac01), and Niobrara (36-62-28-ab01) Counties. Water levels have generally risen from 13 to 40 feet in some of the observation wells since 1995 (USGS, 2001). Total estimated recharge to the Madison Limestone in the Powder River Basin in 1973 was about 75,000 acre feet/year (WSEO, 1976).
	Englewood Limestone (Gurnsey Formation, part)^D	30-60 (Northeastern Basin) 0-50± (Southeastern Basin)	Thin-bedded limestone, locally shaley.	Minor unit of Madison Aquifer System; USGS test: porosity, 15-18%; permeability, <0.1 gpd/ft2.			Generally no ground water development in area (Northern Black Hills - 1958). Formations may contain some water in permeable zones, but are generally considered to be too deeply bured to be considered important aquifers. (Whitcomb, Morris, Gordon & Robinove, 1958)
	Whitewood Dolomite	50-60 (Northeastern Basin) absent (Southeastern Basin)	Massive bedded dolomite, locally cherty.	Minor unit of Madison Aquifer System; the few existing wells also produce from the Madison aquifer. USGS test: porosity, 10-25%; specific capacity, 15 gpm/ft; permeability, <0.1-11 gpd/ft2; transmissivity, 6400 gpd/ft.

Northeast Wyoming River Basins Water Plan Final Report

III Available Surface Water and Ground Water Determination

Northeast Wyoming River Basins Water Plan
Final Report