Laserfiche WebLink
<br />INTRODUCTION <br /> <br />" <br /> <br />. <br /> <br />During 1982, preliminary plans and studies were made to scope new Colorado <br />River Storage Project (CRSP) marketing criteria for the Post-1989 period. At <br />a public information forum held June 8, 1982, in Salt Lake City, Utah, some <br />elements and options being considered were disclosed for public comment. <br />SUbsequently, a refined definition of CRSP resource probabilities was deemed <br />necessary. A hydrologic study was designed to increase the sample size of <br />capability and generation that might be expected under future conditions, <br />especially during the post 1989 period. This report will describe the basic <br />assumptions and procedures used in the study and summarize the salient study <br />results. <br /> <br />STUDY DESCRIPTION <br /> <br />The 1982 Power Marketing Hydrologic Study was designed to supplement other <br />long-range predictive studies performed by the Bureau of Reclamation, Upper <br />Colorado Region (BuRec) by increasing the number of results for probability <br />purposes without jeopardizing accuracy. The BuRec 1983 hydrology study for <br />power repayment (hydrologic basis for BuRec's 26th Annual Report) was used as <br />a base. The CRSP 10n9-range computer simulation model was used without <br />change. The data base that support the model including water supply, <br />depletion schedules, release schedules, startin9 conditions, sedimentation, <br />unit maintenance, etc., were all used without change. The typical scheme <br />used in BuRec's indexed sequential water supply modeling procedure indexes <br />every 5th year and produces 15 sequences. A minor change in the control file <br />causes each and every year to be indexed and produces 75 sequences. This was <br />the only change made to differentiate this study from the 1983 hydrology <br />study for power repayment (RRS83-1). A microfiche copy of the program <br />listing and all data files used in RRS83-1 is available for inspection in <br />Western's Salt Lake City Office. A brief description of the data base <br />follows: <br /> <br />Water Supply <br /> <br />. <br /> <br />The traditional hydrology base for the CRSP model is the monthly flow records <br />from 1906 to present, modified to reflect 1968 depletions. The last year of <br />record included in this study is 1980. For study purposes, it is assumed <br />that WY 1980 is followed by WY 1906. Depletions since 1968 and future <br />depletions as described in the Depletion Schedule are simulated by the <br />model. It is from this modified base of historical flows that estimates for <br />future hydrologic conditions are selected. <br /> <br />The indexed sequential method for simulating future conditions selects a <br />beginning year of hydrology for application to the beginning study year. <br />Typically, the first sequence would index 1906 water year and apply that to <br />the first year of the study (1983 in this case). Water year 1907 is applied <br />to 1984 and 1908 is applied to 1985 and so on until the desired study length <br />is obtained. The next sequence would index another beginning water year to <br />be applied to the first year of the study and the whole process is repeated <br />