Wyoming State Water Plan, Wyoming Water Development Office
Rafting on Snake River Lake Marie, Snowy Mountains Wyoming Wind River Range picture

Northeast Wyoming River Basins Water Plan
Technical Memoranda

SUBJECT: Appendix I
Environmental Uses

PREPARED BY: HKM Engineering Inc.

DATE: March 2002


INTRODUCTION

Environmental uses of water in the Northeast Wyoming River Basins are largely non-consumptive. For instance, instream flows by definition maintain water in the channel to improve habitat. Environmental uses can also be characterized as consumptive. Consider, for instance, wetlands maintenance: surface water spread over a large area increases the amount of surface area evaporative losses.

This memorandum details the water losses associated with environmental uses, including desired reservoir pool levels and release rates, instream bypass requirements made for fisheries and wildlife, local environmental concerns surrounding environmental uses, and where possible, attempts to bracket the optimum stream flows and reservoir levels for environmental use.

INSTREAM FLOWS

Because instream flows can ensure that minimum levels of water are available to environmental uses from the stream rather than being completely appropriated to other uses, they have received much attention in the recent past. Under the 1986 Wyoming statute 41-3-1001 to 1014, the Wyoming legislature codified "instream flows" as a beneficial use of water in the state. The same legislation details how instream flow water rights are filed, evaluated, and ultimately regulated.

The instream flow law change to in-channel use allows instream flow water rights to be filed or granted on unappropriated water originating as natural flow or from storage in existing or new reservoirs, though the water right is held by the State of Wyoming. The use of natural flow sources is defined as the minimum needed to maintain or improve existing fisheries. The use of stored water is defined as the minimum needed to establish or maintain new or existing fisheries.

The law also requires that that Wyoming Game and Fish Commission identify stream segments for instream flow filings and the minimum flows required. The Wyoming Water Development Commission then files the application with the State Engineer's Office in the name of the State of Wyoming.

Wyoming law makes some specific points about instream flows that anyone contemplating an instream flow right must understand:

A single instream flow permit is on file in the Northeast Wyoming River Basins.

Table 1: Instream Flow Filing, Wyoming Game and Fish Department
Drainage Tributary Location Flow/Timing Priority
Sand Creek Redwater Creek From the south boundary of the SW quarter of the NE quarter, section 7, township 52, range 60 to the north boundary of the NE quarter of the west quarter, section 5, township 52, range 60 (2.5 miles long). 21 cfs, Nov. 1-Dec. 31
16 cfs, Jan. 1-April 30
18 cfs, May 1-Oct. 31
12/7/1987

The Sand Creek instream flow proposed reservation has been approved and adjudicated by the State Engineer's Office. This instream flow segment is provided in a GIS data theme for the Northeast River Basin as part of this study (Figure 1).

Because environmental concerns are interested in instream flows throughout the state, the number and location of these rights are subject to change. Wyoming Game and Fish Department instream flow supervisor Tom Annear is currently evaluating a number of streams in the state as candidates for instream flow rights.


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COAL BED METHANE PRODUCED WATER

All coal bed methane (CBM) activities are dependent on lowering the pressure over the coal seam through reducing the column of water in the coal aquifer. The water produced from these wells is not used consumptively - at least initially. The water is simply transferred from groundwater to surface water status.

Environmental concerns about this water fall into two categories: quantity and quality.

Quantity

To determine quantity, HKM made an estimate of the produced in the Northeast River Basin based on an analysis of the Oil & Gas Conservation Commission's online data. (See the Industrial Use Memo for more detail on this process.) The estimate shows 5,161 wells producing an average of just less than 35,296 acre-feet in the year 2001 in the basin.

Environmental concerns about this quantity of groundwater now flowing over the surface include increased sedimentation in streams; increased erosion in everything from the draws and gullies collecting the discharges to main-stem rivers downstream; constant presence of water over soils in areas historically watered only in brief episodes; and increased flooding.

Unfortunately, little data are available to substantiate estimates of increased flows as a result of CBM activity. One recent attempt to generate better information on the effects of increased surface water flows yielded a channel width data index. Dr. Greg Wilkerson, a civil engineering professor at the University of Wyoming, notes that the lack of flow data kept him from being able to model flow effects, but that the index produced by the study provides a means of determining how much change has occurred. The index and report are available through the Water Resources Data System at the University of Wyoming.

Quality

A few of the water quality concerns resulting from CBM activity include the interaction of sodium-adsorption ratio (S.A.R.) in the produced water with soils downstream of the discharge; the variable nature of potential pollutants like sodium, barium, iron, and manganese in produced waters; the emergence of salt crusts on newly waterlogged clays; and the reaction of organisms (from microinvertebrates to fish to humans) to the produced waters in draws, ponds, or rivers.

The Wyoming Department of Environmental Quality has established a general permit for coal bed methane discharge waters that requires operators to monitor their discharges based on the following tables.

Table 2: WDEQ Water Quality Division Coal Bed Methane General Permit Monitoring Parameters and Limits
Parameter Limits
Total Petroleum Hydrocarbons Daily Maximum - 10 mg/l
Specific Conductance Daily Maximum - 7,500 micromhos/cm
Radium 226 Daily Maximum - 1pCi/l
pH 6.5 to 8.5 standard units
Total Iron Daily Maximum - 60 µg/l
Total Manganese Daily Maximum - 10 µg/l
Total Barium Daily Maximum - 200 µg/l
Chlorides Daily Maximum - 46 mg/l

Table 3: WDEQ Water Quality Division Coal Bed Methane General Permit Monitoring Requirements
Parameter Measurement Frequency Sample Type
Total Petroleum Hydrocarbons Once every 6 months Grab
Specific Conductance Once every 6 months Grab
pH Once every 6 months Grab
Radium 226 Annually Grab
Total Flow (Million gallons/day) Monthly Continuous
Total Iron Annually Grab
Total Manganese Annually Grab
Total Barium Annually Grab
Chlorides Annually Grab

Operators' coverages under the general produced water discharge permit are dependent on staying within the limits above.

Organizations outside the state government have been calling for more information to form the basis for regulation ofCBM produced water. For instance, the Coal Bed Methane Coalition in Buffalo, Wyoming, would like to evaluate discharge alternatives. A memorandum distributed in late October 2001 assesses the need for further research on discharge alternatives:

Watershed-based water management plans and landowner associations are key to controlling impact and taking maximum advantage of produced water. Alternatives to discharge such as irrigation, storage and retrieval, dust control, and fire suppression all must be tested and evaluated.Consideration must be given to surface water, alluvial underflow, and groundwater. The effects of recharge on alluvium are difficult to study yet very important as alluvial aquifers are important for agriculture. On the obverse of the coin, drawdown issues must be addressed in the deeper aquifers. Means to minimize and mitigate transboundary effects on downstream parties must be identified and implemented where appropriate.

Further data availability regarding CBM impacts will probably further evolve the debate over regulations and potential mitigations.

WETLANDS MAPPING

Wetlands are transitional lands between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water. For purposes of the classification, wetlands must have one or more of the following three attributes:

  1. at least periodically, the land supports predominantly hydrophytes;
  2. the substrate is predominantly undrained hydric soil; and
  3. the substrate is non-soil and is saturated with water or covered by shallow water at some time during the growing season of each year.

The wetland classification system is hierarchical, with wetlands and deepwater habitats divided among five major systems at the broadest level. The five systems include Marine (open ocean and associated coastline), estuarine (salt marshes and brackish tidal water), Riverine (rivers, creeks, and streams), Lacustrine (lakes and deep ponds), and Palustrine (shallow ponds, marshes, swamps, sloughs). Systems are farther subdivided into subsystems, which reflect hydrologic conditions. Below the subsystem is the class, which describes the appearance of the wetland in terms of vegetation or substrate. Each class is further subdivided into subclasses; vegetated subclasses are described in terms of life form and substrate subclasses in terms of composition. The classification system also includes modifiers to describe hydrology (water regime), soils, water chemistry (pH, salinity), and special modifiers relating to man's activities (e.g., impounded, partly drained).

The NWI coverage for the Northeast Wyoming River Basins contains 3 systems:

The three systems are divided into six- subsystems:

The subsystems are filrther divided into classes. The classes describe the general appearance of the habitat in terms of either the dominant life form of the vegetation or the physiography and composition of the substrate-features that can be recognized without the aid of detailed environmental measurements. The following list identifies and defines the NWI classes in the Northeast Wyoming River Basins:

The National Wetlands Inventory (NWI) of the U.S. Fish and Wildlife Service produces information on the characteristics, extent, and status of the Nation's wetlands and deepwater habitats. Federal, state, and local agencies, academic institutions, the U.S. Congress, and the private sector use this information. The Emergency Wetland Resources Act of 1986 directs the service to map the wetlands of the United States. The NWI has mapped 89% of the lower 48 states, and 31% of Alaska. The act also requires the service to produce a digital wetlands database for the United States. About 39% of the lower 48 states and 11% of Alaska are digitized. Congressional mandates require the NWI to produce status and trends reports to Congress at 10-year intervals.

The U.S. Army Corps of Engineers (Corps) administers the Section 404 program governing the discharge of dredge and fill material into waters of the U.S. as defined and guided by Section 404 of the Clean Water Act. The wetlands that fall within the Section 404 regulation are referred to as jurisdictional wetlands. The indicators of wetlands suggested by the Corps in their 1987 Manual for Delineation of Wetlands, are used as the basis for determining the presence of a wetland by most scientists and engineers. Other, broader, definitions of wetlands are generally used in addition to, or in place of, the Corps guidelines when the ecological aspects of wetlands are the focus. The U.S. Fish and Wildlife Service scientists and many other scientists, land use planners, and watershed or water quality managers, utilize the Cowardin system for more in-depth identification or classification of wetlands. The NWI's mapping corresponds with the Cowardin system.

In 1982, the NWI produced the first comprehensive and statistically valid estimate of the status of the Nation's wetlands and wetland losses, and in 1990 produced the first update. Future national updates were scheduled for 2000, 2010, and 2020. The status of the 2000 review is not known.

The Wyoming Spatial Data and Visualization Center downloaded the digital line graphs (dig) from the NWI web page and converted the dig data to Arc/Info vector coverages with matching attributes. Vector coverages include both line (riverine) and polygon (lacustrine and palustrine) wetland features.

The wetlands mapping in the Northeast River Basin is provided as a GIS data theme for this study (Figure 2).


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MINIMUM RESERVOIR CONSERVATION POOLS AND BYPASS REQUIREMENTS

In general, conservation pools are intended to provide the minimum volume of water necessary to maintain the existing aquatic life in the reservoir. Because on-stream reservoirs disrupt the natural flow in a stream, minimum bypass requirements are often dictated during the permitting process to provide the minimum flow downstream required to maintain existing fisheries.

Minimum conservation pools and minimum flow releases are not available or are nonexistent for the reservoirs of the Northeast Wyoming River Basin. This is not to say they aren't an issue; the low water levels in Keyhole Reservoir in the 1990s brought the issue to a boil. Low levels affected the fisheries and made boating on the reservoir unsafe. Some Wyoming residents considered reexamining the Belle Fourche Compact with South Dakota to impose a minimum pool level in the reservoir. Better water years followed before any such attempt was made, and the issue has lain dormant since.

COMMENTS AND CONCERNS

In soliciting comments and concerns on environmental issues in this basin, HKM personnel queried groups with environmental concerns in the basin with the following questions:

Not every group responded. As a result, this memo doesn't attempt to provide a compendium of all environmental concerns in the basin - only those provided in response to e-mailed, telephoned, or mailed queries.

Group: Wyoming Game and Fish Department
Contact: Bob McDowell, Regional Fisheries Supervisor

Many ofMcDowell's environmental concerns spring naturally from his work with freshwater fisheries in the basin and have been developed and explained in his agency's Fishery Management Plans.

NOTE: The Wyoming Game and Fish Department has maintained a stream classification map ranking free-flowing surface waters based on their trout biomass, accessibility, and aesthetics. Because users became confused about the function of this map, the department no longer supports it (Stewart, 3 Dec. 2002).

Group: Wyoming Natural Diversity Database
Contact: George Jones, Natural Heritage Ecologist

Jones is concerned that the riparian woodlands along the Cheyenne be maintained. The Cheyenne River supports extensive cottonwood stands because flow regimes have been altered little in the past. Other rivers, like the Little Missouri, have some existing riparian woodlands, but Jones maintains that the Cheyenne has the greatest stands in this basin. These stands are coincident with a complete native fish fauna.

These stands of cottonwoods demand flooding and new sediment bars to re-seed and re- establish, and Jones would like to ensure that the natural flow regime of the Cheyenne is maintained in the future.

Group: Nature Conservancy
Contact: Sally Morton, staff member

The Nature Conservancy has an established goal of "the long-term survival of all viable native species and community types through the design and conservation of portfolios of sites within ecoregions," (TNC, p.2). To that end, the organization produced a guide for its efforts in the "Northern Great Plains Steppe" (an area encompassing parts of Alberta and Saskatchewan, Canada, Wyoming, Montana, North and South Dakota, and Nebraska) in a 1999 document, Ecoregional Planning in the Northern Great Plains Steppe. There, the organization rates the relative urgency of its efforts in the geographic areas in the steppe and the species at stake.

Area Species/Eco-Type
Cheynne River Riparian Cottonwood stand
Hat Creek Alpin fever few
Toadstool Badlands
Upper Niobrara River Ute's ladies' tresses
Riparian community

In one way or another, all of these listings are concerned with water in the Northeast Wyoming River Basins, and as George Jones, a contributor to the Nature Conservancy's study (see separate listing under Wyoming Natural Diversity Database), stated, much of this concern stems from an interest in ensuring that the current, near-virgin flow regimes of the tributaries of the Cheyenne are maintained.

Group: Wyoming Outdoor Council
Contact: Dan Heilig, executive director

Heilig's primary concern was that wetlands and riparian habitats have no appropriation under Wyoming water law at present. He would like to see these areas protected with allocations of water for their consumptive use under Wyoming law.

Heilig's group would also like to see some of the produced water from oil and gas activities in the basin augment streamflows to maintain habitat, though the variability in water quality from wells is a concern.

Group: Powder River Basin Resource Council
Contact: JudyMcCullough, member, and Kevin Lind, director

Judy McCullough submitted comments focusing on concerns over the stability of Keyhole Dam when it is kept full, coal-bed methane produced water's sodium absorption ratio and pollutants, and a general mistrust ofCBM operators when maintenance of water quality and quantity may be in their hands.

Group: Ducks Unlimited
Contact: Barry Floyd, Wyoming state staff, and Jon Roaldson, regional biologist

Ducks Unlimited (D.U.) has taken an active part in changing how water is used in riparian areas in the Northeast Wyoming River Basins. The organization knows from its research and experience that ducks and other waterfowl need wetlands and open water for breeding, nesting, rearing, feeding and isolation from land-based predators. The Northeast Wyoming River Basins isn't the perfect home for waterfowl, representing as it does the western extreme of the central flyway (Barry Floyd, April 10, 2001). But D.U. has worked with area landowners, the WGFD, various foundations, the USFWS, and the Natural Resource Conservation Service to help clean up waters, rehydrate old oxbows, create impoundments, and generally create new wetlands wherever possible.

The group is interested in the Northeastern Wyoming River Basin for its status as a secondary, pothole terrain for waterfowl. D.U. considers the area a priority for long-range planning. In addition to its natural amenities for ducks, the Northeast Wyoming River Basins doesn't have the pesticides or predator pressures that are found in the traditionally more productive plains regions to the east. As a result, the area supports a higher ratio of young per nest than can be found to the east (ibid).

D.U. regional biologist Jon Roaldson notes that the water needs of ducks are straightforward. In general, the best water conditions can be found in littoral zones, where light penetrates to the bottom of the channel or still water. This allows a number of invertebrates to survive that in turn provide waterfowl with the protein they need in breeding and brooding seasons. For everything except diving ducks, the optimal depth is approximately three feet, with anything greater than six feet being excessive (Roaldson, D.U., April 2001).

The Northeast Wyoming River Basins has been pockmarked with glacial or wind-formed palustrine basins that migratory waterfowl consider attractive, according to Roaldson. The shallow, warmer waters of these basins provide good breeding and courtship habitat, but must have seasonal wetlands of heavy brush to support brooding activities. Many of the dams created to hold coal bed methane discharge water create the shallow basins Roaldson talks about, but they need time to develop proper benthic life or their water quality is not conducive to that life, limiting their productivity for waterfowl.

Group: Sierra Club
Contact: Elizabeth Howell, Wyoming staff

The Sierra Club's primary environmental concern relating directly to water in the basin centers on the State of Wyoming's establishment of Total Maximum Daily Loads (TMDLs). These thresholds of pollutant streams can accept and still meet their designated uses are required in the 1972 Clean Water Act.

The Wyoming Department of Environmental Quality judged that it didn't have the information to create TMDLs, so in 1990, it surveyed conservation districts, the U.S. Forest Service, the Bureau of Land Management, the Wyoming Game and Fish Department, and others, seeking professional opinions of impairment. The resulting list of impaired streams, called the 303(d) list for Section 303(d) of the Clean Water Act, has been submitted to the U.S. Environmental Protection Agency since then.

The Sierra Club Legal Defense Fund sued the State of Wyoming in Denver Federal Court on December 9, 1996, on behalf of Wyoming Outdoor Council, Biodiversity Associates, and American Wildlands. The groups sought to require Region VIII EPA to implement the TMDL program in Wyoming. The litigants claim that the state has not adequately monitored its streams, has not listed all impaired streams, and has not developed sufficient point or nonpoint source TMDLs.

Since then, the venue for the case has been changed to Casper, the Wyoming DEQ has established a five-year timeframe for monitoring streams on the 1996 303(d) list and a ten-year schedule for adopting TMDLs on those streams with credible data indicating TMDLs need to be established. The 1996 draft list included 336 streams. The revised, 1998 303(d) draft list included

According to the most current information available on the WDEQ web site, Wyoming's 2000 303(d) list has 46 members on Table A (with quality impairments), 13 on Table B (with Waste Load Allocation permits expiring), and 23 on Table C (with threatened water quality). Of these, the Northeast Wyoming River Basin has five on Table A, none on Table B, and one on Table C.

2000 303(d) List Members in the Northeast Wyoming River Basins

2000 303(d) list-Table A, Northeast Wyoming River Basins (Waterbodies with water quality impairments)
Waterbody Name Location State
Impairment
Priority Use Impairment/
Threat
Date Listed
Belle Fourche River Between Arch Creek and Hulett Fecal coliform L Contact Recreation 1996
Belle Fouche River From Keyhole Resevoir to an unknown distance above Rush Creek Fecal coliform L Contact Recreation 1996
Donkey Creek From confluence with Belle Fourche River to Stonepile Creek Fecal coliform M Contact Recreation 2000
Gillette Fishing Lake City of Gillette Phosphates L Warm-Water Fishery 1996
Siltation L Warm-Water Fishery 1996

2000 303(d) list-Table B, Northeast Wyoming River Basins (Waterbodies with Waste Load Allocation discharge permits expiring)

No listings in the Northeast Wyoming River Basins

2000 303(d) list-Table A, Northeast Wyoming River Basins (Waterbodies with water quality threats)
Waterbody Name Location State
Impairment
Priority Use Impairment/
Threat
Date Listed
Poison Creek (Cheyenne River) S16-17, T46N, R63W Oil Seeps L Wildlife/Agriculture 2000

(Wyoming's 2000 305(b) State Water Quality Assesment Report, Appendix B)

Howell is concerned about the sudden reduction in the number of streams on the 303(d) list, about the difficulty in applying the list criteria, the lack of water quality issues stemming from CBM discharges, and that ranching and timber interests might be released from responsibility with the new list.

Group: U.S. Fish and Wildlife Service
Contact: Michael Long, Field Supervisor

In a letter, Long expressed his agency's environmental concerns based on the list of threatened or endangered species present in the basin (in accordance with section 7(c) of the Endangered Species Act of 1973.

Table 5: USF&WS Listed and Proposed Species for Threatened and Endangered Status
Species Status Expected Occurrence
Black-footed ferret Endangered Potential resident in prarie dog colonies
Canada lynx Threatened Resident of forested areas
Bald eagle Threatened Nesting, winter resident, migrant
Mountain plover Proposed Grasslands statewide
Whooping crane Experimental Resident, migrant
Ute ladies' tresses Threatened Seasonally moist soils and wet meadows of drainage below 6,500 feet in elevation

Table 6: USF&WS Candidate Species for Threatened and Endangered Status
Species Expected Occurence
Black-tailed prarie dog Grasslands generally east of the continental divide
Swift fox Grasslands statewide
Sturgeon chub Powder River drainage

OPTIMUM RESERVOIR LEVELS/STREAM FLOWS

Few respondents wanted to answer the question about what reservoir levels or stream flows could maximize environmental use of water in the basin directly. For Ducks Unlimited representatives, proper streamflows should include high, peaked hydrographs to ensure that palustrine areas and riparian areas are often recharged. They would probably also maintain that lakes should be dropped quickly to levels that maximize the area covering water less than six feet deep Conversely, trout enthusiasts would seek to ensure that stream flows were maintained to maximize the dissolved oxygen in streams (rapid, turbulent flow). High flows for extended periods can bring more sediment into suspension, but sudden, high, peaked hydrographs can flush sediments to clean gravel spawning beds. And trout (and other fish) tend to have large winterkill rates in small, shallow lakes (Guenther and Hubert, Great Basin Naturalist, p. 282). A method for determining pool minima to maximize the survival and propogation of salmonids in Wyoming has been published (Guenther and Hubert, Environmental Management) and provides guidance in determining the optimum operating range in reservoirs for waterfowl and salmonids.

REFERENCES

Annear, Tom, Wyoming Game and Fish instream flow specialist, personal communication, 7 March 2001.

Christiansen, B.J., and Steward, Mickey, "Management of Development Issues," for the Coal Bed Methane Coalition, received 30 Oct. 2001 by e-mail as an electronic text document.

Cowardin, L.M.; Carter, V.; Golet, F.C.; LaRoe, E.T., "Classification of Wetlands and Deepwater Habitats of the United States. Performed for the U.S. Department of the Interior Fish and Wildlife Service Office of Biological Services, Washington, D.C., Dec. 1979.

Dey, Paul, Wyoming Game and Fish Department instream flow specialist, personal communication, 6 Nov. 2001.

Floyd, Barry, Ducks Unlimited Wyoming state director, Personal Communication, April 10,2001.

Guenther, Paula M. and Hubert, Wayne A., "Factors Influencing Dissolved Oxygen Concentrations During Winter in Small Wyoming Reservoirs," Great Basin Naturalist. Vol. 51, no. 3, Sept. 1991.

Guenther, Paula M. and Hubert, Wayne A., "Method for Determining Minimum Pool Requirements to Maintain and Enhance Salmonid Fisheries in Small Wyoming Reservoirs," Environmental Management. Vol. 17, no. 5.

Heilig, Dan, Wyoming Outdoor Council Executive Director, personal communication, 9 April 2001.

Howell, Elizabeth, Wyoming Sierra Club staff, personal communication, 3 April 2001.

Jones, George, Wyoming Natural Diversity Database Natural Heritage Ecologist, personal communication, 19 April 2001.

Long, Michael M., U.S. Fish and Wildlife Service field supervisor, written personal communication, 3 April 2000.

McCullough, Judy, Powder River Basin Resource Council member, e-mail communication, 19 April 2001.

McDowell, Bob, Wyoming Game and Fish Department regional fisheries supervisor, personal communication, 9 March 2000.

Northern Great Plains Steppe Ecoregional Planning Team, Ecoregional Planning in the Northern Great Plains Steppe. The Nature Conservancy, 4 Feb. 1999.

Roaldson, Jon, Ducks Unlimited regional biologist. Personal Communication, April 10, 2001.

U.S. Fish and Wildlife Service, National Wetland Inventory, 1997.

U.S. Environmental Protection Agency, "Total Maximum Daily Load (TMDL) Program: 1998 303(d) List Fact Sheet for Wyoming," web site, 8 November 2001, http://oaspub.epa.gov/waters/state_rept.control?p_cycle=1998&p_state=WY

Whitaker, Mike, Wyoming State Board of Control Superintendent, personal communication, 12 Dec. 2000.

Wilkerson, Gregory V., University of Wyoming School of Engineering, Civil Engineering Dept, personal communication, 15 October 2001.

Wyoming Department of Environmental Quality, Water Quality Division, "Authorization to Produce Discharged Water from Coal Bed Methane Wells Under the National Pollutant Discharge Elimination System (NPDES)," May 14, 1999, web site, http://deq.state.wy.us/wqd/watershed/91131.pdf

Wyoming Department of Environmental Quality, Water Quality Division, Wyoming's 2000 305 (b) State Water Quality Assessment Report, Cheyenne, Wyoming, June 2000.

Wyoming State Engineer's Office, Wyoming Instream Flow Applications Database, 2000.

Wyoming Statutes 41-3-1001 to 1014.

Wyoming Water Development Commission, Wyoming Instream Flow Filings GIS Coverage, 2000.