Laserfiche WebLink
TABLE 2. Channel Sizes <br />Waldo Canyon <br />(above US 24) <br />Bottom width (feet) <br />Side slope (horiz.,H to 1 vert.) <br />Design depth, D (feet) <br />.. ,c <br />Sediment & Sediment Control <br />12.0 <br />2.0 <br />3.3 <br />East tributary <br />8.0 <br />2.0 <br />1.4 <br />No information is presently available regarding the sediment <br />transport regime of Waldo Canyon and only a limited amount of <br />data is available on Fountain Creek. The US Geological Survey <br />collected periodic suspended sediment data from December, 1984 <br />through September, 1985 and again from December, 1985 through <br />Septmeber, 1986 at the Fountain Creek gaging station just west of <br />Colorado Springs (M07103700). This limited sampling gives some <br />information to the sediment transport characteristics of tie <br />area. The Fountain Creek produces generally low concentrations <br />of suspended sediment, from 10 to 200 mg/1, during the loW and <br />near average flows of 15 cfs (29 year average). However, during <br />the spring snowmelt season when the ground thaws and rapid melt <br />commences, the stream averages several hundred mg/1 of suspended <br />sediment with the recorded maximum concentration at the station <br />being 5,120 mg/1 in 116 cfs of flow on April 30, 1985 which also <br />corresponded to the day of peak runoff for that year. Some <br />particle size analyses by the USGS indicate that during low and <br />normal flows, the transported sediment is distributed about 258 <br />sand size and 758 silt size particles. As expected, during the <br />higher runoff, this distribution is approximately reversed. <br />Thus, during higher runoff, onsite sediment control measures will <br />be most effective because the larger particles are more easily <br />controlled by filtering and sedimentation. <br />_~ <br />SedtmercC wiY2 bcnteaeeJe~-~fisite as an •o~r ga2rtg eontre2 proeJranr to <br />neinix-ise the a:neae~-c£-disturbed watori3~that ie delivered to <br />the streams. This sediment control plan will include the <br />following elements: 1) no drainage channel construction will <br />occur dtsri~tho- It season of Narch through June; <br />-2) cul be installed wherever it is necessary <br />for egat osa Waldo Canyon or the East tributary; <br />3) hap balee~+fi~~t-pi'3ced between the drainage channels and any <br />areas that have been dioturbed and not reclaimed, either <br />temporarily or permanently (as shown in figure Exhibit G-3); and <br />4) a sediment pond will be maintained below the confluence of the <br />two streams and above highway US 24. This pond will be utilized <br />to provide sedimentation o! particles transported in the runoff <br />which results from laced disturbance caused by the pit operation. <br />~~ j' , <br />f~ <br />Surface Water Responses: Summit Pit Application psgA 0 <br />