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i~ <br />STATE OF COIORApO PiC HnH^ D. LxMM, Gav ern or <br />DEPARTMENT OF NATURAL RESOURCES <br />Harris D. Snerman. Executive Director <br />iVIINED L~~iD RECLA1VIaTION <br />723 Centennial Building, 1313 Sherman Street <br />Denver, Colorado 80203 Tel. (30318923567 <br />Hamlet J. Barry, II I, <br />Director <br />M E M O R A N D U M <br />T0: Carol Pahlke <br />FROM: Jerry Zirr^fer <br />DATE: September 10, 1979 <br />RE: Bourn Coa l <br />I have reviewed the sediment control plan and hydrology package for the <br />purpos~ Bourg Coal Mine. It contains numerous deficiencies which must <br />be corrected before we can approve the application. <br />1) Mining Through Mann Draw <br />a. Water Rights - klthough this area is primarily the concern <br />of the Division of Water Resources, water rights should be addressed <br />in the application submitted to this office. <br />(1) Would mining through Mann Draw affect water supply <br />(surface or groundwater) to the stock pond located <br />downstream along Mann Draw? <br />(2) The applicant's well permit was denied because the <br />water was probably tributary to the Canadian River. <br />Mining through Mann Draw would interrupt both surface <br />and sub-surface flow downstream. Is this of concern <br />to Water Resources? <br />b. Channel Reconstruction -Reconstruction of Mann Draw should <br />be based upon geomorphic considerations rather than r~~.~ing upon <br />structural controls (i.e. gravel). <br />(1) The division needs a longitudinal profile of Mann <br />Draw including upstrea;' downstream, and the area to be <br />mined. The reconstructed channel should integrate with <br />the undisturbed profile as smoothly as possible. <br />(2) Under the interim regs, stream channel reconstruc- <br />tions are viewed as equivalent to permanent diversions. <br />As such they should be designed to safely pass the 100- <br />year event. (This should be calculated using an ac- <br />cepted hydrologic method). <br />(3) Dimensions of the actual channel should be based <br />upon a width/depth ratio determined from field data. <br />(4) I would prefer that the channel not be immediate- <br />ly lined with gravel. This approach should be re- <br />served as a mitigation of erosion problems to develop. <br />(5) The channel way should be revegetated with the <br />same type of vegetation as occurs presently. <br />