Laserfiche WebLink
<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />3.0 Stagecoach Dam <br /> <br />! <br /> <br />stagecoach dam is a 135 foot high roller compacted <br />concrete (RCC) gravity dam constructed on the Yampa <br />River in Routt County, Colorado in 1988. The dam is <br />located in the SW1/4 of Section 29, T4N, R84W, 6th <br />Principal Meridian, at a point approximately 16.3 river <br />miles upstream from the City of Steamboat Springs. <br /> <br />, <br /> <br />It has a normal operating volume of 33,275 acre-feet <br />and a normal surface area of 775 acres. There is 10 <br />feet of freeboard between the elevation of the 50 foot <br />wide central overflow spillway and the top of the dam. <br />The crest is 24 feet wide and 362, feet long. The <br />upstream face of the dam is vertical and the downstream <br />face is on a slope of 0.8 horizontal to 1.0 vertical. <br />The outlet works is controlled by a 36 inch diameter <br />jet flow gate valve which has a maximum release of <br />about 450 cfs at normal operating volume. <br /> <br />For purposes of this investigation, Stagecoach dam <br />will be assumed to fail "in the dry" under the <br />following conditions: <br /> <br />Water level - <br /> <br />at the crest of the emergency <br />spillway, elevation 7200. <br /> <br />Surface Area - <br /> <br />normal operating surface <br />,area, or 775 acres <br /> <br />Reservoir Volume - normal operation capacity, <br />33,275 acre-feet <br /> <br />Time of breach - <br /> <br />15 minutes <br /> <br />The slope of the channel downstream from Stagecoach <br />dam varies from about 80 feet per mile immediately <br />,below the dam to about 25 feet per mile in Lake <br />Catamount a few miles downstream. Manning's roughness <br />coefficient will be assumed to be 0.08 in the three <br />mile long canyon just below the dam and 0.04 elsewhere. <br /> <br />4 <br />