Laserfiche WebLink
<br />o <br />~ <br />M <br />..... <br />o <br /> <br />COLORADO WATER CONSERVATION BOARD <br />215 state Services Building <br />1525 Sherman Street <br />Denver, Colorado 80203 <br /> <br />C:"'j <br /> <br />April 2, 1965 <br /> <br />M E M 0 RAN DUM <br /> <br />TO: <br /> <br />Felix L. Sparks, Director. <br /> <br />FROM: <br /> <br />R. M. Gildersleeve, Chief Engineer. <br /> <br />SUBJECT: <br /> <br />possible Procedure in Meeting Rio Grande Compact Delivery <br />Schedules. <br /> <br />In the IS-year period, 1950 through 1964, deliveries of <br />water at the gaging station on the Rio Grande near Lobatos have been <br />less, in every year except 1958, than those required by the schedules <br />set up in the Rio Grande Compact. The required delivery amounts are <br />based on stream flows for each of the calendar years at index stations <br />on the upper reaches of the Rio Grande at Del Norte, the Conejos River <br />at Mogote, and on Los pinos and San Antonio Rivers, tributaries of the <br />Conejos, near Ortiz, Colorado. <br /> <br />The deficiencies of deliveries have varied during the <br />period between a low of 18,000 acre-feet and a high of 156,000 acre- <br />feet, with an average of about 60,000 acre-feet. On the average, also, <br />the deficiencies amount to approximately 10 percent of the aggregate <br />canal diversions from these streams below the index stations. <br /> <br />Regardless of the cause of the deficiencies over this long <br />per1od, it appears that under present conditions the only way in which <br />the schedules can be met consistently is by a reduction in diversions. <br />The annual stream flows at the index stations can be forecast reason- <br />ably well from consideration of the recorded water content of the <br />snowfall at snow courses in the watershed. However, the time, magni- <br />tude, or duration of the peak flows can not be accurately foreseen. <br />Further, the exact amount of delivery deficiency, or possible excess, <br />can not be determined until the end of any calendar year. The most <br />reasonable approach to accomplishing scheduled deliveries over a series <br />of years is probably to attempt to meet, in anyone year, at least <br />the average deficiency. The following is a suggested procedure to <br />attain this result. <br /> <br />Rio Grande. The average annual deficiency in delivery for <br />the 1950-1964 period is 36,000 acre-feet. The safe channel capacity <br />