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" 1IM~8/96 15:20 BOYLE ENGINEERING ~ 303 866 4474 NO. 957 [;102 'r- .\ ~~ 00Q339 MEMORANDUM TO: FROM: SUBJECT: Ray Alvarado MegFrantz October 8, 1996 Vampa River iDstream itow issues. Task 3.01 Here's a summary of our telephone c:onversation this morning, addressing some specifics we've discovered in the process of modifying the Phase 2 instream flow files. The italicized text covers the resolution of matters and our "marching orders" as I understand them. It appears that the instream flow files (ifs, ifr, and ifa) for Phase 2 were generated by running watright and then making hand edits which are not described specifically in the documentation. Instream flow rights on Williams Fork and East Williams Fork were added, probably because the adjudication was more recent than the latest version of the water right database. In preparing .ifs and.ifr jiles for Task 3.01. Boyle will hand edit accordingly and ma1lUQ]ly put revision notes into the flle header. At our: diSCIetlon, we may automate this step later ifit becomes helpful to us under subsequent subtasks because we have to eenerate the files repeatedly. The .ifa file was created manually (through the gui) for Phase 2. Boyle wllllik.ewise create the .f/afile manually. In the Phase 2 model, one instream flow structure (582404) was used to cover the Bear River MSF from Stillwater Reservoir to Phillips Creek. Three nodes were used in the model within the reach. According to the water rights tabulation, this stretch of the river is governed by two instream flow rights, one for 5 cfs from Stillwater Reservoir to Yamcolo Reservoir, and a second for 12 cfs from Yamc:olo to Phillips Creek. The different flow amounts were able to be exerted in the Phase 2 model through the demand file (ifa). which has a separate right and record for each of the three nodes. Thus the first node had a demand of 5 cis, and the second and third node had a demand of Scfs during winter and 12 cfs during summer. (This appears to be an error since we fmd DO indication in the water rights database or the bound tabulation that the Yamc:olo-to-Phillips right varies through the year; we believe the correct demand is 12 cfs throughout the year.) Now that we are representing instream flow rights as a reach with only one water right, only one demand can be entered in the ifa file to control the entire reach. Boyle will use 12 eft as the decreed amount in lhe ifr file, and a demand of 5cft in winrer and 12 cft in summer, for structure 582404 in the Task 3.01 and Phase 3 model. This approach will probably come closest to effecting the same water allocation as the Phase 2 model without adding a new structure, because calls from the downstream right in the Phase 2 model control junior rights in the upstream instxeam flow reach anyway. Boyle should document in thejile header that 582404 does nOl exactly represent actual instreamflow rights in two respects: 1) one struclure has been used in the model oller two reaches, and 2) the right in the model varies through the year, whereas actual rights are constant through the year. Another way of thinking of it is the upstream reach has too high a summer flow in the model, and the downstream reach has too Iowa winter flow in the model. ~ Boyle previously brought to the State's attention the fact that the decreed amount in the ifr file for two rights was less than the [l'l"y;mum monthly demand for the same right in the ifa file. That is, decreed amount reflected the winter flow am,ount, but the higher summer right flow appeared in the demand file. ~ r Gru..n .. "