Laserfiche WebLink
STATE OF COLORADO <br />MINED LAND RECLAMATION DIVISION <br />Department of Natural Resources <br />1373 Sherman St., Room 215 <br />Denver, CO 80203 <br />303 866-3567 <br />FA x: 303 832-8106 <br />of ~~~ <br />~~~~~ <br />N~7°~"`j ~ ~$ <br />•+ <br />a <br />s re96 a <br /> Roy Romer, <br /> Governor <br />DATE: July 9, 1990 Div Sion Director <br />T0: Catherine W. Begej <br />FROM: J.M. Clap ton C~ ~tJ"' 1 M C- <br />RE: Marr Strip, C-80-006, tAid-Term Review Responses on Hydrology 7',f~ <br />Kerr Coal has submitted a rewritten hydrologic section for surface runoff. <br />This work has been previously approved. The following are mostly <br />typographical misuses or omissions. <br />1. Map 22 is referenced for the surface water calculations. Map 16A is <br />the correct map. <br />2. The embankment top width formula is incorrectly presented on pages <br />23-162 and 168. <br />3. The equation for "S" is improperly presented on page 23-14. <br />4. Ditch A-2 is not shown on map 16A. Since this ditch is significantly <br />larger, its location and the associated drainage area is important. <br />5. On page 23-43, there isn't any description of spillway bottoms as <br />shown in Plate 1, Volume 10 of the existing permit application. <br />6. On page 23-43 Kerr states that a trash rack/anti vortex device as <br />shown in Volume 10, Plate 1 in the approved permit. This decreases <br />efficiency of this structure and impacts, especially, the pond's <br />capacity in the 25 year - 24 hour event. <br />The drainage designs parameters are clouded by not showing sub-areas <br />on Map 16A. I was able with some difficulty to satisfactorily <br />reconstruct these areas so feel that their design parameters are <br />reasonable. <br />Ditch designs appear to be properly presented and adequate. <br />/lac <br />8646E <br />