WSP04875 - Laserfiche WebLink

Home Browse Search

I. Introduction Members of the Colorado River Work Group have been seeking a process which will identify "surplus" conditions and the masnitude of water available under ,such conditions as envisioned by the Criteria for Coordinated Long-Range Operation of Colorado River Reservoirs (operating criteria). This proposal builds on the original California pr~posal to investigatE> using a 5 year window. existing reservoir conditions, and varying 5 year forecast probabilities in supporting determinations of surplus. This proposal includes a demonstration study which is "designed to be a concise E~xaminatilon of the likelihood of surplus flows from the Colorado River system within between water years 1992 and 1996. The methods used in this proposal have identified no surplus water in the Colorado River system under current reservoir conditions during the study period until the probability of nonexceedence virgin flow approaches 90% at Lees Perry, Arizona. II. California Concept Paper On June 22, 1989, the Colorado River Board of California wrote a draft "Concept Paper Relative to Secretary of the Interior's Decision Regarding Basin States' Unused Apportionments Under 'Normal' Releases from Lake Mead" (Refer to Appendix II). This concept paper deliberates the possibility of ,identifying water which would otherwise be forced from the 'reservoir system 1n a five year period of "minimum probable water supply scenario.1I That "unused apportionment" water is then rescheduled and delivered on an uninterruptable basis. The draft concept paper, by definition, lacked detailed methodology and supporting information. Since the draft concept paper was issued, there have been no follow up studies which have attempted .to validate it' s. concepts or to identify the unused apportionment. ,This study is an attempt to identify this water. 1