Memorandum Concerning Weather Modification on the Colorado River Basin

Letter: To Stewart Udall, from Pierce Linaweaver, "Weather Modifications on the Colorado River Basin," March 13, 196

Memorandum Concerning Colorado River Basin Project

Memorandum: To Stewart Udall, from Pierce Linaweaver, "Colorado River Basin Project," December 28, 196

Memorandum Concerning Colorado River Basin Project

Memorandum: To Stewart Udall, from Pierce Linaweaver, "Colorado River Basin Project," December 28, 1966, page 1UNITED STATES DEPARTMENT OF THE INTERIOR OFFICE OF THE SECRETARY WASHINGTON. D.C. 20240 December 28, 1966 Memorandum To: The Secretary From: Pierce Linaweaver Subject Colorado River Basin Project OB The presentation to Sam Hughes and other BOB staff members by Floyd Dominy made clear Bureau of Reclamation views principally with respect to one aspect of the Colorado River project, namely the Hualapai Dam. This pictorial and somewhat factual presentation should enable rational decisions concerning the dam in view of the position of the Sierra Club and other conservationists. The next step, it would appear to me, would be to present to Sam Hughes of the BOB staff an overall Interior position as to the package that should make up the Administration's bill to be introduced in Congress, and the justification for Interior's position. This meeting should be held within the next several days so that the final Administration bill can be agreed upon and necessary reports can be prepared. Interior's presentation to the BOB should highlight: the water problem in central Arizona; the part of the water problem to be solved by the CAP; the need for 425 mw of power to pump the water and that hydro power from the dam at the Hualapai site is most economical; that if the dam is built, the site should be developed to its full potential (1) so that excess power capacity can be used to provide peaking power and marketing to non-Federal utilities and thereby provide revenue for a Basin development fund and (2) for recreation and for benefits to the Indians; other conservation and preservation benefits such as the Grand Canyon National Park could be extended and permanently protected; and the overall economics of the proposal including the water pricing, payout, etc. The results of this meeting should then produce agreement on the Administration bill. If budget limitations at this time dictate some change in Interior's proposal, the bill should include those facilities that are clearlyEpson Perfection 4870 Photo, 400 dpi, 24 bit, 2,668,253 byte

Memorandum Concerning Weather Modification on the Colorado River Basin

Letter: To Stewart Udall, from Pierce Linaweaver, "Weather Modifications on the Colorado River Basin," March 13, 1967, page 2If the flow averages 18.0 million acre feet per year, after weather modification begins, the chances that weather modification really does NOT work and that the high flows are just a wet cycle are then the following: Years of Measurement After Weather Modification Begins Chances that flow is greater than 18.0 million acre feet per year but weather modification does NOT work 1 1 in 4 3 1 in 9 9 1 in 60 Thus after 3 years, there is only one chance in nine that the average flow would have been 18 million acre feet per year anyway. So it will take many fewer years to be reasonably convinced of success, if weather modification yields as high as 3.0 million acre feet per year. Thus, interpretation of the success of weather modification depends on the actual increase in yield and on whether a wet or a dry cycle occurs during the years of measurement. I hope this will indicate some of the uncertainties involved and why it is difficult to make definitive statements on the probable success of weather modification. Consequently, my answer to the stated question would be: It may take 10 years of measurements, after full-scale weather modification begins, if the increased yield amounts to 1.5 million acre feet per year on the Colorado River Basin. It will take fewer years if it turns out that the yield from weather modification is higher. Pierce 2Epson Perfection 4870 Photo, 400 dpi, 24 bit, 2,352,458 byte

Memorandum Concerning Weather Modification on the Colorado River Basin

Letter: To Stewart Udall, from Pierce Linaweaver, "Weather Modifications on the Colorado River Basin," March 13, 1967, page 1UNITED STATES DEPARTMENT OF THE INTERIOR OFFICE OF THE SECRETARY WASHINGTON, D.C. 20240 March 13, 1967 Memorandum To: The Secretary From: Pierce Linaweaver Subject: Weather Modification on the Colorado River Basin How many years will it be before we can be reasonably sure that weather modification can be considered reliable as a source of water supply on the Colorado River Basin? 1. Assume that weather modification yields 1.5 million acre feet per year (i.e., increases yield from about 15 to 16.5 million acre feet per year). If the flow averages more than 16.5 million acre feet per year after weather modification begins, the chances that weather modification really does NOT work and that the high flows are just a wet cycle are then the following: Years of Measurement After Weather Modification Begins Chances that flow is greater than 16.5 million acre feet per year but weather modification does NOT work 1 1 in 3 3 1 in 4 9 1 in 7 Thus after 9 years, there is still one chance in seven that the average flow would have been 16.5 million acre feet per year anyway. So it will take a number of years to be reasonably convinced of success, if weather modification yields about 1.5 million acre feet per year. 2. Assume that weather modification yields 3.0 million acre feet per year (i. e., increases yield from about 15 to 18 million acre feet per year).Epson Perfection 4870 Photo, 400 dpi, 24 bit, 2,389,720 byte