| OCR Text |
Show APPENDIX VI VI 17 12 COLORADO RIVER STORAGE PROJECT start significant filling during the spring runoff of 19G3. Flaming Gorge will probably start filling about the same time. Navajo win be about 1 year earlier. Curecanli is not scheduled to start storing water until the fall of 19G5. Suggestions were made that tabular forms illustrating the application of principle 5, along with explanatory sheets and an accompanying statement of criteria for operation of Lake Mead to determine Hoover basic firm power in computing allowance for deficiency, be made a part of the general principles and criteria by attachment. We full}-recognize that it is only through having this information available that a precise understanding of the intended application of principle 5 is gained. Notwithstanding this, however, we are not inclined to incorporate either the tabular forms or the accompanying explanatory material into the general principles and criteria, ^ye believe such action would give undue significance to a matter which must remain open to the exercise of secretarial judgment, particularly as to the use of forms. There is included with this memorandum, however, the tabular forms and explanatory materials which we would intend to use, at least initially, for the purpose of computing the Hoover basic firm and the diminution in power generation under the formula of principle 5. The forms included herewith are different from those supplied at the Boulder City meeting in June 1960. One revision made in the material is in the method-of handling the efficiency factor. A further review of the tentative forms supplied at the Boulder Cit}' meeting showed that in this respect they followed the present billing process rather than the intent of principle 5, which was to be a theoretical computation based on overall efficiency. Our position on use of the 83 percent efficiency factor is, we believe, well set forth in the January 18, 1960, memorandum and need not be repeated here. Suffice it to say that in the original Hoover firm energy computation made for the general regulations, 83 percent efficiency was applied in satisfaction of the formula-acre-feet times head times efficiency times 1.025 equals kilowatt-hours. It was our intent to again apply the 83 percent efficiency factor in this manner. The tentative forms, however, showed a netting out of service station use, leakage and pumpage which is appropriate for the billing process, but not for the theoretical computation. We do not, of course, intend to change the actual billing process. Another revision made is in the method of handling evaporation losses of the storage project reservoirs. For reasons explained hereinafter, such evaporation is not now included as a part of the theoretical-streamflow of the Colorado River at Grand Canvon. Representatives of the upper basin have expressed concern over the contemplated inclusion of evaporation from the storage project reservoirs as a part of theoretical streamflow used in the formula for computing allowance. We have given this matter considerable attention and have concluded that our past studies on handling of evaporation losses have not been consistent with our handling of stream depletions caused by the participating projects. All factors considered and in the interest of consistency, we have concluded that storage project reservoir evaporation should not be considered as part of the theoretical streamflow to be used in calculating diminution in Hoover generation. |
