Laserfiche WebLink
<br />. <br /> <br />sary to raise the height of the dam, enlarge the spillway, and stabil- <br />ize the dam by placing additional material on the downstream face. <br />The probable cost of this alternate is $5.59 million. Based on an <br />economic evaluation, it was determined that a capital construction <br />cost of $5.59 million, even if financed at low interest rates over a <br />long time period, would be clearly beyond the financial capability of <br />the San Luis Valley Irrigation District. Therefore, it appears that <br />this alternate is not economically feasible unless a grant is obtained <br />for nearly 90 percent of the cost. <br />By rehabilitating the dam to safely pass the one-half probable <br />maximum flood, the Corps of Engineers' classification for the dam <br />would change from "seriously inadequate" and "unsafe" to "inadequate." <br />In order to pass the one-half probable maximum flood, it would be <br />necessary to increase the dam height by six feet and stabilize the dam <br />through placement of additional material on the downstream face. No <br />spillway enlargement would be required. The probable cost of this <br />alternate is $1.04 million. Based on an economic evaluation, It was <br />estimated that the San Luis Valley Irrigation District could repay a <br />long term low interest loan of up to approximately $515,000. There- ~ <br />fore, financing of this alternate would necessitate a grant for at <br />least $500,000. Since it was determined that it was not economically <br />feasible to construct the probable maximum alternate mentioned previ- <br />ously, our secondary recommendation is that the San Luis Valley Irriga- <br />tion District implement this alternate such that the dam could safely <br />pass the one-half probable maximum flood. As a part of this alternate, <br />a flood warning program would be designed and implemented to minimize <br />or eliminate potential loss of life resulting from a large flood pass- <br />ing the dam or a dam failure caused by a flood larger than the one-half <br />probable maximum flood. <br />A third alternate was also evaluated which involves limiting the <br />storage capacity to 40,000 acre-feet and developing a flood warning <br />program. By limiting storage capacity to 40,000 acre-feet, the exist- <br />Ing dam could safely pass the one-half probable maximim flood. The <br />estimated cost for this alternate is $360,000.. Although this alternate <br /> <br />. <br /> <br />. <br /> <br />-5- <br />