Powder River Biological Survey 

and Implications for Coalbed 

Methane Development

:

Prepared For: 

Mr. Kevin Lind 

Powder River Basin Resource Council 

23 N. Scott 

Sheridan, WY 82801 

10 March 2004 

Prepared By:
Powder River Biological Survey 10 March 2004 

Confluence Consulting, Inc. 

Table of Contents 

Executive Summary ............................................................................................................ 1 

1.0 Introduction.....................................................................................................................3 

2.0 Study Area ......................................................................................................................5 

2.1 Setting .................................................................................................................5 

2.2 Water Use Classifications ...................................................................................5 

2.3 Hydrology ...........................................................................................................7 

2.4 Fluvial Geomorphology....................................................................................13 

2.5 Land Use ...........................................................................................................13 

3.0 Methods..........................................................................................................................14 

3.1 Physicochemical Water Quality Parameters..................................................... 14 

3.2 Initial Site Procedures....................................................................................... 17 

3.3 Biota..................................................................................................................18 

4.0 Results and Discussion ................................................................................................27 

4.1 Physicochemical Water Quality........................................................................27 

4.2 Periphyton.........................................................................................................29 

4.3 Macroinvertebrates ...........................................................................................40 

4.4 Fish....................................................................................................................44 

4.5 Reptiles and Amphibians .................................................................................. 47 

4.6 Birds..................................................................................................................48 

4.7 Habitat...............................................................................................................48 

5.0 Conclusions and Management Implications ................................................................ 61 

5.1 Clear Creek .......................................................................................................61 

5.2 Piney Creek.......................................................................................................62 

5.3 Powder River ....................................................................................................62 

5.4 Summary of Recommendations........................................................................ 65 

6.0 Literature Cited ............................................................................................................67 

Appendix A: Diatom Counts ........................................................................................... 70 

Appendix B: Macroinvertebrate Counts and Metric Calculations.................................. 103 

Appendix C: Lab Reports .............................................................................................. 128 
Powder River Biological Survey 10 March 2004 

Confluence Consulting, Inc. 

Table of Figures 

Figure 2-1: Map of the study area...................................................................................... 6 

Figure 2-2: Mean monthly stream flows measured at gaging stations on Clear Creek 

(06324000) and Piney Creek (06326500).......................................................................... 8 

Figure 2-3: Maximum mean daily flows measured at gaging stations on Clear Creek and 

Piney Creek during the period of record............................................................................ 8 

Figure 2-4: Mean monthly flow measured at gaging stations on the Powder River within 

the study area. ................................................................................................................... 9 

Figure 2-5: Maximum mean daily flows measured at gaging stations on the Powder 

River within the study area. ............................................................................................ 10 

Figure 2-6: Stream flow measured at the Arvada gaging station (6317000) and Moorhead 

gaging station (6324500) from May 19, 2002 through October 31, 2002....................... 11 

Figure 2-7: Mean daily flows measured at Sussex and Arvada gaging stations on the 

Powder River in 1951, 1978, 1980, and 1990................................................................. 12 

Figure 4-1: Percent of diatoms from Clear Creek in each of four salinity classes as 

assigned by Van Dam et al. (1994).................................................................................. 32 

Figure 4-2: Percent of diatoms from Clear Creek in each of five moisture classes (Table 

4-6) as assigned by Van Dam et al. (1994)...................................................................... 32 

Figure 4-3: Percent of diatoms from Piney Creek in each of four salinity classes as 

assigned by Van Dam et al. (1994).................................................................................. 34 

Figure 4-4: Percent of diatoms from Piney Creek in each of five moisture classes (Table 

4-6) as assigned by Van Dam et al. (1994)...................................................................... 35 

Figure 4-5: Percent of diatoms from Powder River in each of four salinity classes as 

assigned by Van Dam et al. (1994)................................................................................. 39 

Figure 4-6: Percent of diatoms from the Powder River in each of five moisture classes 

(Table 4-6) as assigned by Van Dam et al. (1994). ........................................................ 40 

Figure 4-7: Wetted widths measured on reaches of Clear Creek and the Powder River. 51 

Figure 4-8: Width-to-depth ratios measured on Clear Creek and the Powder River....... 51 

Figure 4-9: Bank angles measured on Clear Creek and the Powder River...................... 52 

Figure 4-10: Depth or distance of bank undercut measured on Clear Creek and the 

Powder River. .................................................................................................................. 52 

Figure 4-11: Fish habitat cover types observed on Clear Creek and the Powder River. . 54 

Figure 4-12: Water depths measured along the thalweg on Clear Creek and the Powder 

River................................................................................................................................. 55 

Figure 4-13: Channel units comprising sites on Clear Creek and the Powder River. ..... 55 

Figure 4-14: Percent of pool forming feature classes observed on Clear Creek and the 

Powder River. .................................................................................................................. 56 

Figure 4-15: Substrate composition measured with pebble counts on Clear Creek and the 

Powder River. .................................................................................................................. 56 

Figure 4-16: Average percent cover by riparian cover types on Clear Creek and the 

Powder River. .................................................................................................................. 59 

Figure 4-17: Proximity weighted human influence index reaches on Clear Creek and the 

Powder River. ................................................................................................................. 60 
Powder River Biological Survey 10 March 2004 

Confluence Consulting, Inc. 

Table of Tables 

Table 2-1: USGS gaging stations used to describe surface water hydrology for Clear 

Creek, Piney Creek, and the Powder River................................................................. 7 

Table 3-1: Physicochemical water quality parameters assessed for streams in the Tongue 

River basin. ............................................................................................................... 15

Table 3-2: USGS sampling stations used in generating descriptive statistics for 

evaluating physicochemical water quality parameters. ............................................ 15 

Table 3-3: Distribution statistics for physicochemical water quality parameters sampled 

in the Powder River, Wyoming used as a reference for all Powder River sites. ...... 16 

Table 3-4: Distribution statistics for physicochemical water quality parameters in Clear 

Creek near Arvada (USGS Station 6324000) used a reference for site Clear Creek C. 

.................................................................................................................................. 16 

Table 3-5: Distribution statistics for physicochemical water quality parameters in Clear 

Creek near the Ucross, Wyoming (USGS Station 6320400) used as a reference for 

sites Clear Creek A and B......................................................................................... 16 

Table 3-6: Distribution statistics for physicochemical water quality parameters in Piney 

Creek near Ucross, Wyoming (USGS Station 6323500).......................................... 17 

Table 3-7: Distribution statistics for physicochemical water quality parameters sampled 

in tributary streams in the Tongue and Powder River basins (STORET database) 

used as a reference for Spotted Horse Creek ............................................................ 17 

Table 3-8: Diatom association metrics used to evaluate biological integrity in Montana 

streams: reference, range of values in Montana streams, and expected direction of 

metric response to increasing anthropogenic perturbation or natural stress (Bahls 

2001). ........................................................................................................................ 19 

Table 3-9: Criteria for rating levels of biological integrity, environmental impairment or 

natural stress, and aquatic life use support in wadeable plains streams of Montana 

using selected metrics for benthic diatom associations ............................................ 20 

Table 3-10: Metrics calculated for macroinvertebrate populations sampled on streams in 

the Tongue River basin, June 2001. (Modified from Barbour et al. 2000)............... 22 

Table 3-11. Criteria for metric scoring for Montana plains streams (Bukantis 1998)..... 24 

Table 3-12: Fish metrics, metric categories, catchment adjustment equations and scoring 

calculation after Bramblett et al. (2003). .................................................................. 25 

Table 3-13: Catchment area for sampling sites on Clear Creek and the Powder River 

used in normalizing fish taxa richness metrics. ........................................................ 25 

Table 4-1: Results of field meter readings collected on the Powder River and assessed 

tributaries. ................................................................................................................. 28 

Table 4-2: Results of water chemistry analyses conducted on grab samples collected on 

the Powder River and tributaries............................................................................... 28 

Table 4-3: Physicochemical measures of water quality collected on Spotted Horse Creek 

following advent of coalbed methane development.. ............................................... 29 

Table 4-4: Relative abundance of cells and rank by biovolume of diatoms and genera of 

non-diatom alge in periphyton samples collected from Clear Creek (2002). ........... 30 

Table 4-5: Percent relative abundance of major diatom species and values of selected 

association metrics for periphyton samples collected from Clear Creek (2002). . .. 31 
Powder River Biological Survey 10 March 2004 

Confluence Consulting, Inc. 

Table 4-6: Classifications of diatoms based on moisture affinities. ................................ 33 

Table 4-7: Relative abundance of cells and ordinal rank by biovolume of diatoms 

(Division Bacillariophyta) and genera of non-diatom algae in periphyton samples 

collected from Piney Creek in 2003.......................................................................... 33 

Table 4-8: Percent abundance of major diatom species and values of selected diatom 

association metrics for periphyton samples collected from Piney Creek and the 

Powder River in 2003.. ............................................................................................. 36 

Table 4-9: Relative abundance of cells and ordinal rank by biovolume of diatoms 

(Division Bacillariophyta) and genera of non-diatom algae in periphyton samples 

collected from Powder River in 2002 and 2003. ...................................................... 37 

Table 4-10: Percent abundance of major diatom species1and values of selected diatom 

association metrics for periphyton samples collected from Piney Creek and the 

Powder River in 2003.. ............................................................................................. 38 

Table 4-11: Metrics and scoring for macroinvertebrates collected on Clear Creek using 

criteria developed for plains streams in Montana (Bukantis 1998). ......................... 41 

Table 4-12: Metrics and scoring for macroinvertebrates collected on Piney Creek using 

criteria developed for plains streams in Montana (Bukantis 1998). ......................... 42 

Table 4-13: Metrics and scoring for macroinvertebrates collected on the Powder River 

using criteria developed for plains streams in Montana (Bukantis 1998). ............... 43 

Table 4-14: Fish captured on sampling sites on Clear Creek and the Powder River (2002 

and 2003). ................................................................................................................. 44

Table 4-15: Fish metrics and classification of fishes captured on Clear Creek and the 

Powder River (2002 and 2003). ................................................................................ 45 

Table 4-16: Scores for fish metrics calculated for fish communities sampled on Clear 

Creek. See (Table 3-12) for formulas. ..................................................................... 46 

Table 4-17: Scores for fish metrics calculated for fish communities sampled on the 

Powder River. See (Table 3-12) for formulas.......................................................... 47 

Table 4-18: Reptiles and amphibians encountered at sampling sites on Clear Creek, 

Piney Creek, and the Powder River (A = abundant, C = common, P = present)...... 47 

Table 4-19: Bird species observed at sampling sites on the Powder River, Clear Creek, 

and Piney Creek. ....................................................................................................... 48 

Table 4-20: Results of rapid habitat assessments conducted on reaches of the Powder 

River and Clear Creek using the glide/pool questionnaire. ...................................... 49 

Table 4-21: Results of rapid habitat assessments conducted on reaches of Clear Creek 

and Piney Creek using the riffle/run questionnaire................................................... 50 

Table 4-22: Noxious weeds and invasive plants observed at sites on the Powder River 

and Clear Creek......................................................................................................... 59 

Table 5-1: Rare invertebrates collected from the Powder River by Dr. Dan Gustafson, 

Montana State University, Bozeman (unpublished data). ........................................ 64 
Powder River Biological Survey 10 March 2004 

Confluence Consulting, Inc. 

Executive Summary 

Coalbed methane development in the Powder River basin involves the discharge or 

surface storage of large quantities of saline water. This investigation presents the results 

of a monitoring and assessment approach to evaluate the effects of coalbed methane 

development on three streams in Wyoming, Clear Creek, Piney Creek and the Powder 

River. The analysis included characterization of baseline conditions at current levels of 

coalbed methane development and in some cases allowed inference on the impacts of 

existing coalbed methane development. Parameters assessed included fish populations, 

algal assemblages, aquatic invertebrate communities, habitat condition measures, and 

assessment of chemical water quality. Results provided the basis for the generation of 

management recommendations to promote the sustainable development of coalbed 

methane while conserving ecological and agricultural values. 

Clear Creek and Piney Creek had high levels of biological, chemical, and physical 

integrity. These streams supported healthy aquatic communities and had water low in 

dissolved salts. Habitat conditions were typically excellent indicating existing 

agricultural practices were compatible with maintaining ecological values. Conservation 

of the agricultural and ecological significance of these streams should guide the 

sustainable development of coalbed methane development in these basins. 

The Powder River also had a high level of biological, chemical, and physical integrity 

although its unique nature does not represent the typical ideal of a healthy stream. 

Nevertheless, the Powder River maintained a mostly native assemblage of fish, including 

species such as flathead chub and sturgeon chub that are in decline throughout their 

range. Evaluations of conditions in the Powder River provided cause for concern for the 

persistence of this rare and special ecosystem. 

Analyses of water chemistry suggested that coalbed methane development might be 

resulting in degradation of water quality due to increased loading of salts. Sodium 

adsorption ratio, a measure of the suitability of water for irrigation uses, was substantially 

elevated above typical levels for this river below an area of considerable coalbed methane 

development. In addition, several sampling sites had relatively high levels of salts, 

compared to typical values. Furthermore, high concentrations of dissolved solids in 

Spotted Horse Creek, possibly the result of coalbed methane wastewater, may threaten an 

important channel catfish rearing area downstream in the Powder River. 

The biological communities sampled in the Powder River were adapted to the high 

turbidity, great variability in flows, and moderate salinity. Of concern, however, was the 

rarity of the sturgeon chub, a Wyoming and Montana species of special concern. 

Biologists captured only two sturgeon chub at one location on the Powder River. 

Sampling in the early 1990s found sturgeon chub to be present at considerably more 

locations in the Powder River. These results emphasize the need for additional 

investigation into the status and trend of sturgeon chub in the Powder River. 
Powder River Biological Survey 10 March 2004 

Confluence Consulting, Inc. 

Another concern was the prevalence of salt cedar, an introduced shrub along most of the 

Powder River. This species may have a competitive advantage over cottonwood, 

especially with increased loading of salts. Cottonwoods, however, are vital to both 

wildlife and fish along the Powder River. They provide critical habitat features for 

wildlife such as nesting, roosting, and cover. Cottonwoods also provide large woody 

debris that forms pools, important habitat features for fish. Management of CBM 

wastewater should consider concerns regarding recruitment and maintenance of 

cottonwood stands along the Powder River. 

The use of an adaptive management approach to coalbed methane development was the 

major recommendation from this investigation. Adaptive management entails a strong 

monitoring component to provide feedback and continual refinement of management 

activities. The amount of uncertainty regarding the potential impacts of coalbed methane 

development necessitates an adaptive approach.

**** Powder River Note: 

Powder River has the entire Confluence Report available. If you are interest 

please email your request to info@powderriverbasin.org. Thank you