Wyoming passed its first instream flow water law in 1986, yet today many individuals throughout the state are still uncertain what an instream flow water right is or how it affects existing water rights. Instream flows pertain to a quantity of water that flows through a stream channel and may or may not be adequate to support a fishery, while an instream flow water right is a legal instrument to protect an amount of water necessary to maintain or enhance a new or existing fishery (Merritt 1992).
The history of instream flow water law in Wyoming dates back to the early 1970's, when the first instream flow legislation was considered and defeated in the state legislature, with subsequent bills meeting the same fate. In 1986, supporters began collecting signatures on petitions with the intent of having an instream flow bill on the general election ballot through the initiative process. But before that could happen, the Legislature passed a bill identical to the bill on the petition (Merritt 1992).
In 1986, the Wyoming State Legislature declared that "instream flows to establish or maintain new or existing fisheries is a beneficial use of water subject to normal stream loss" (W.S. 41-3-1001(a)). The primary articles of instream flow water law encompass the following, as taken from the Wyoming Water Statutes: 1) that unappropriated water flowing in any stream or drainage may be appropriated for instream flows; 2) that those instream flows shall be the minimum flow necessary to establish or maintain fisheries; 3) an instream flow water right does not affect any existing water right and does not result in the loss of water for any water user in Wyoming; 4) all water used for the purpose of instream flows shall be applied only to that segment of the stream for which they are granted and that all rights to those instream flow waters are relinquished after passing through the specified stream segment; 5) the water development commission is responsible for conducting an instream flow feasibility study based on Wyoming Game and Fish Department requested flows; 6) an instream flow water right does not guarantee public ingress and egress through or upon private property to reach streams where instream flows are maintained; 7) Wyoming's instream flow law prohibits the Wyoming Game and Fish Department, the ability to condemn any existing water rights to obtain an instream flow and prohibits the State of Wyoming to file for the abandonment of an existing prior water right to obtain an instream flow; 8) an instream flow cannot be granted on the basis of providing benefits for anything other than fisheries resource - i.e. a flow cannot be requested for recreation, wildlife, floating, scenic values, etc.; 9) all compact and decree waters are protected by law; 10) instream flow water rights can only be held by the state of Wyoming.
Instream flow water rights are attained through the collaborative effort of several state agencies, the Wyoming Game and Fish Department (WGFD) Wyoming Water Development Commission (WWDC), and the Wyoming State Engineer's Office (SEO). This process begins with a study conducted by the WGFD. The following narrative presents this process through an example using a recent filing by the WGFD for instream flow rights along a 3.4 mile segment of Deep Creek located within the Little Snake River Basin in Southen Wyoming.
In 1994 a study was conducted as part of an ongoing monitoring and enhancement program for Colorado River cutthroat trout. The goal of the study was to determine instream flows necessary for maintaining or improving Colorado River cutthroat trout habitat in Deep Creek. The objectives were 1) to examine relationships between discharge and physical habitat quantity and quality available to Colorado River cutthroat trout in Deep Creek and 2) to determine instream flow amounts for Deep Creek to maintain or improve Colorado River cutthroat trout populations (Braaten et al. 1995).
Simulations for physical habitat were conducted for spawning, fry, juvenile and adult life stages of Colorado River cutthroat trout. Based upon these simulations, recommendations of 0.5 cubic feet per second (cfs) were requested from October 1 to April 30, 4.6 cfs from May 1 to June 30 and 0.5 cfs from July 1 to September 30. To achieve the requested flow amounts, data was gathered regarding general watershed characteristics, hydrology based on stream gaging stations and water rights near the segment area. A study site was then established comprised of ten transects encompassing riffles, runs and pools to represent habitat found throuhout the middle reaches of Deep Creek. Information gathered from these transects was then applied to the remainder of the segment (Braaten et al. 1995)
The data was then entered into the physical habitat simulation model or PHABSIM. From this model the requested flow amounts are established based on the life stages of the Colorado River cutthroat trout These flow amounts would nearly maximize physical habitat for all life stages and maintain or improve existing physical habitat suitability (Braaten et al. 1995). Following this analysis, a report is generated and submitted along with a standard water rights application to the WWDC This process usually take around 13 months.
The next step in the adjudication process requires the WWDC to submit the application to the SEO. The WWDC also conducts a hydrologic study to determine whether the requested instream flows can be provided from the natural flow of the stream or whether storage water from an existing or new reservoir will be needed for part or all of the instream use. This part of the process usually takes around 10 months.
The WWDC solicits proposals from consulting firms to conduct the feasibility studies. Western Water Consultants, Inc. (WWC) from Laramie, Wyoming was awarded a contract to conduct the study for the Deep Creek instream flow segment, along with six other segments in the Savery area.
The feasibility study consists of many different tasks, one being a water right search for any rights above the downstream end of the instream flow segment. Flow records are also searched for stream gaging stations in the immediate and surrounding area for any information that may be used to analyze the streamflow of the individual instream flow segment. Often times, streams within a particular instream flow segment do not contain gaging stations near the segment and therefore require streamflow generation using other gages in the area and then generating streamflow for a particular segment based on characteristics such as drainage basin area and mean basin elevation versus yield calculations. The HEC4 streamflow simulation model was also used to aid in the extension of streamflow data for streamflow gages having different periods of record (WWC 1996). To derive unappropriated flow estimates for the instream flow segment, the previously derived monthly flows needed to be adjusted to account for senior water rights. These flows were then compared to the requested amounts of instream flow to determine whether or not the requested flows could be met in a month of average flow, during each month of the driest year on record and in each of the twelve driest months for the period of record (WWC 1996).
The mean monthly, dry year monthly and twelve driest monthly flows all indicated that at various times of the year shortages will exist, resulting in insufficient unappropriated direct flows available to provide the requested instream flows. A reservoir storage analysis was then conducted using a simple reservoir mass balance to determine the reservoir storage required to provide the requested instream flow amounts for the instream flow segment (WWC 1996).
Lastly, a daily flow exceedance analysis was conducted to determine the percent of time flow rates are equal to or exceed a specific flow rate, measured at set intervals. The requests are then deemed feasible if the exceedance reaches an established percentage (WWC 1996). The WWDC "exceedance criteria deems an instream flow filing hydrologically feasible if the requested, unappropriated flow is equaled or exceeded at least 50% of the time during each filing period" (Brinkman 1996).
Upon completion of the final draft, the feasibility report is submitted by the consultant to the WWDC for review. Once the review is completed and meets the satisfaction of the WWDC, it is then submitted to the SEO for their consideration of the permit.
The final step in the appropriation process rests with the SEO and usually takes around 19 months. After receiving reports from the WGFD and WWDC, the state engineer may conduct his own evaluation. Before granting or denying a permit for instream flow in the specified stream segment, the State Engineer must conduct a public hearing in the vicinity of the instream flow segment and consider all available reports and information. Additional comments are usually accepted for 30 days after the hearing, and finally, a decision is made and a water right is issued. If granted, an instream flow permit can contain a condition for review of continuation of the permit at a future time (Jacobs 1990).
The instream flow appropriation goes into effect the date the State Engineer approves the permit. The water right cannot be adjudicated by the Board of Control for three years thereafter. An instream water right has a date of priority as of the date that the application was received and recorded by the State Engineer, and all senior priority water rights must be recognized in administration of the stream. The state engineer cannot issue an instream flow permit if it would result in loss of a portion of Wyoming's consumptive share of water allocated by interstate compact of U.S. Supreme Court decree, or if it would result in more water leaving Wyoming than allocated for uses downstream of Wyoming (Jacobs 1990).
In summary, instream flow water rights are legal instruments to protect an amount of water necessary to maintain or enhance new or existing fisheries throughout Wyoming. Since the inception of the law in 1986, a total of 68 filings have been made, 44 filings have gone to hearing, and 8 have reached permit status. However at this time, no instream flow water rights have been adjudicated due to questions by the Board of Control pertaining to prior irrigation rights and those of abandonment (Bames 1997). Once these questions are answered, adjudication of instream flow water rights will begin.
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