Laserfiche WebLink
<br />. <br /> <br />(. <br />./ <br /> <br />.: <br /> <br />. <br /> <br />1(' <br /> <br />., <br /> <br />.. l <br /> <br />" <br /> <br />- 25 - <br /> <br />dated September 28, 1960. The Corps found that a flood prevention <br />program depending primarily upon the enlargement and improvement of <br />the Indian Wash flood channel could not be justified because of <br />existing low capacities which would require replacement of: nine <br />road bridges, two freeway (highway) bridges, and a railroad culvert <br />about 600 feet long. ' . <br /> <br />The letter report by the Corps of Engineers recommended that <br />one of the alternative plans studied involving a single dam and <br />reservoir on the mainstem of Indian Wash above the High Line Canal <br />appeared to be the best plan that could be devised for flood protection <br />along this stream and that this plan should be made the subject of <br />detailed study by the Soil Conservation Service. <br /> <br />As a result of this letter report, the proposed program for <br />further study was presented to the sponsors and received their <br />approval. The sponsors expressed their wishes for more detailed <br />information on this proposal. The Soil Conservation Service <br />proceeded with the detailed planning. <br /> <br />In analyzing the structure for the desired flood detention <br />capacity, consideration was giv~n to providing the maximum capacity <br />that would provide the desired level of protection consistent with <br />economic justification (see maps, Figures 1 and 4). <br /> <br />The da~age evaluations for present conditions were based on <br />conditions without the improved Indian Wash flood channel. D~~age <br />evaluations with project conditions were based upon the improved <br />capacity or the Indian Wash flood channel which is now in the process <br />of completion by the sponsors. <br /> <br />The maximum rainfall recorded during 67 years of record at the <br />Weather Bureau Station at Grand Junction occurred Sept~ber 1896 <br />when 3.03 inches were measured. <br /> <br />The selected flood detention capacity of the reservoir is <br />1,045 acre-feet. This storage equals three inches of runoff that <br />might be expected from a 4.l-inch rainfall occurring in a six-hour <br />period. <br /> <br />The selected structure provides storage at a m~nlrnum cost per <br />acre-foot. The structure as planned will retard and by-pass through <br />its spillways without overtopping the probable maximum six-hour <br />storm. <br /> <br />