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I Flow Incremental Methodology Physical Habitat Simulation System (IFIMIPHABSIM) data that was collected by both the CDOW and by consultants for the Denver Water Department. Recall that during this period of time Denver Water was seeking a pennit to build the Two Forks Reservoir project and they were compiling information for the Denver Systemwide Environmental Impact Statement (SEIS). Since the Two Forks project had the potential to effect flows and fisheries elsewhere in the Denver Water collection system, the SEIS was requiring analysis of flow and fisheries effects in many river basins on both the east slope and the west slope. The Blue River was a major focus for the SEIS because the Blue River was a major source of water that would have been stored in Two Forks Reservoir if it had been built. I I The Blue River from Dillon Dam to the Colorado River was (in 1987) and still is one of ouly nine designated "Gold Medal Waters". In addition, the Blue River from Green Mountain Dam to the Colorado River was (in 1987) and still is designated as "Wild Trout Water". Both of these special designations are initiated and established by formal action of the Colorado Wildlife Commission. Gold Medal Waters are streams, rivers and lakes that provide the public with an opportunity to catch trophy trout; Wild Trout Waters are streams and rivers where the population is not augmented by stocking of trout by the DOW. At the time of the CWCB instream flow appropriations (1987) on the Blue River, the Blue River from Breckenridge to the Colorado River was managed with a 16 inch minimum size limit, 2 fish daily bag limit, and fishing by fly and lure ouly. All of these designations and special fishing regulations remain in place; in some isolated sections the regulations have been strengthened by adding catch and release requirements. I I In CDOW's transmittal of instream flow recommendations to the CWCB we cited the above information regarding the designated status of the fishery resource in the Blue River. We emphasized the importance of the Blue River fishery with the following statements: . "Next to the South Platte River from Cheesman Reservoir downstream, the Blue River is the most popular and intensively used stream fishery in Colorado and is situated within easy access of Colorado's front range population centers." . "'lbe Blue River is regarded by the CDOW as a stream resource of extraordinary importance and value mid one in which instream flow plays a vital role in the maintenance of an excellent sport fishery." . "DOW flow reconnnendations on the Blue River reflect our position that reasonable instream flows on the river will be those that preserve the integrity and quality of the existing sport fishery while recognizing competing developmental demands." . "The Blue River is of great economic value to Summit County and the State of Colorado and it is totally reasonable to expect our (seasonal) flow reconnnendations to support and protect the economic viability of the Blue River Gold Medal fishery." I I I I I These statements were intended to illustrate the biological and economic importance of the Blue River fishery. It is with these sopporting statements that the DOW developed flow reconunendations that were more closely aligned to "optimum flows" rather than the more typical "maintenance flow" standard used in most instream flow analyses. We believed that the quality of the Blue River fishery raised the reasonableness bar to approach "optimum flow protection" rather than the typical "minimum amount necessary" standard that is normally applied to the instream flow program In the case of the Blue River, . the CWCB agreed to appropriate flows which approached the optimum amounts where water availability analyses supported those flow reconnnendations. I I I The section of the Blue River that is affected by the proposed acquisition of water is the section from Boulder Creek downstream to Green Mountain Reservoir; a distance of approximately 11.1 miles. The original instream flow reconnnendation for the section of the Blue River from Rock Creek to Green Mountain Reservoir was 90 cfs winter (October - April) and 125 cfs summer (May - September). The Boulder Creek confluence with the Blue River is 1.6 miles downstream of Rock Creek. This flow reconnnendation was based on both R2CROSS data and IFIMIPHABSIM data. The optimum combined life stage flow was detennined to be approximately 125 cfs but a wide band of potentially acceptable flows existed from 79 cfs to 186 cfs. Adult and juveuile habitat was optimized at approximately 125 cfs, while fry and spawning habitat was optimized at flows of approximately 100 cfs and 186 cfs, respectively. It was noted that a great deal of tributary inflow occurs between Rock Creek and Green Mountain Reservoir. This fact was further illustrated .by the segmentation of this part of the Blue River that occurred after water availability analyses were conducted by the CWCB (with assistance from the Division of Water Resources and Denver Water). I I After the CWCB received the DOW's flow reconnnendations, CWCB staff initiated their hydrologic analyses to see if water was physically available for the instream flow appropriation. Denver Water was also very interested in the instream flow proposals due to their involvement with the SEIS. Ultimately, the resolution of the Blue River instream flow issues was based on a 50 cfs release from Dillou Reservoir and we then used the tributaries to "build" a hydrograph. Where water availability analyses supported the CDOW's original flow reconnnendations, the CWCB filed on those amounts; if the hydrologic data showed another flow to be available, then that became the default filing. We took the four original instream flow segments and divided them further into seven segments. The above described segment (Rock Creek to Green Mountain Reservoir) was divided into three segments described below: I I I I