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Appendix 14-5 <br /> <br />United States Department of the Interior <br />BUREAU OF LAND ~L-1~~1,1GEMENT <br />GrandJuncdon Resource Nea <br />2815 H Road <br />Gruid Juncrion, Colorado 81506 <br />JUN 2 7 2000 <br />Dan Mathews <br />Division of Minerals and Geology <br />2148 Broadway, #C-5 <br />Grand Junction, Colorado 81503 <br />Re: Powderhom Coal Company <br />Stream Crossings in Coal Canyon <br />DMG Permit C-81-041 <br />Deaz Mr. Mathews: <br />~~ <br />~ ~ <br />M 0.CPLYPFFEx I'O: <br />3400 (CO-130) <br />Bruce Fowler, BLM Gtand Junction Field Office Geologist, and Jim Scheidt, BLM Northwest <br />Center Hydrologist, met with you in the field on June 15, 2000. The purpose of the field visit <br />• was to discuss the possible retention of culverts along the Coal Canyon road to better provide <br />public access, and assess potential maintenance issues for BLM if the culverts were retained. <br />In order to assess the current situation and evaluate issues with retaining the culverts, a reach of <br />Coal Canyon was walked by Bruce and Jim. They started at the azched culverts, went up the <br />channel over a series of four rock check dams, past the set of 36 inch culverts encased in <br />concrete, to a reach of the channel where the natural stream sinuosity, channel slope, and channel <br />cross sectional azea could be observed. This upper reach was considerably different from the <br />realigned section between the culverts which includes the check dams. The stream reach <br />between the culverts, had a stair step profile due to the check dams and the sediment detained <br />behind the sttvctures, had a wide flat channel bottom and tapered channel sides, had just one <br />minor meander, showed azeas where the rocks used to construct the checks had moved, some as <br />far as the mouth of the azched culverts. The upper reach had a more gentle gradient, significantly <br />higher sinuosity with typical cut banks on the outside of meanders, a narrower channel bed, and a <br />terrace or fioodplain along much of the alignment. <br />BLM understands that following completion of mine reclamation, the Division of Minerals and <br />Geology (DIvIG) is recommending removal of the culverts and replacement with low water <br />crossings. However, there is an option of retaining the culverts. The determination would be <br />based on public access being better served by leaving the culverts in place, and BLM assuming <br />future maintenance responsibilities. BL~I is interested in keeping the culverts, but has a few <br />• concerns regazding the current hydrology in Coal Canyon. Although the canyon is generally dry, <br />when convective storms pass [hrough the area, the watershed is capable of producing significant <br />runoff very quickly. These flashy events are capable of moving very lazge volumes of sediment, <br />Z( <br />