Laserfiche WebLink
__ iiiiuiiiiiiiiiiiii - <br />,_ sss <br /> <br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1313 Sherman St., Room 215 <br />Denver, CO 80203 <br />Phone: 1303) 866-3567 <br />FAX: U03) 832-8106 <br />Date: November 19, 1993 <br />To: Larry Routten <br />Steve Renner <br />From: David Berry <br />Re: GEC West Pit Diversion Design <br />p4 ep~o <br />~~ ' b <br />~~~ <br />0 <br />~ r816 ~ <br />Roy Romer <br />Governor <br />Michael B. Long <br />Division Direcbr <br />I have calculated additional channel designs, based upon the previously calculated 10-year, <br />24-hour peak flaw of 198 cubic feet per second. These are derived using the SEDCAD soft- <br />ware, and the results are attached as Tables 1 and 2. The calculations are provided for <br />comparison to the previously calculated 100-year, 24-hour designs. <br />The methodology recommends the same riprap specification fora 15- or 20-foot channel, using <br />the 10-year, 24-hour design event. You will note that channel size specifications are not much <br />different from the 100-year, 24-hour design, and riprap is still recommended throughout the <br />upper, middle and lower sections of the diversion project. Recommended riprap sizing is some- <br />what smaller for the 10-year design, compared to the 100-year design, as would be expected. <br />DAB/bjw <br />Attachments <br />m:\oss\bjw\deb.pec <br />C ~ <br />