Laserfiche WebLink
• Temporary erosion control measures will be implemented during the construction of the <br />haul roads. Straw bales or other alternative sedimentation control devices will be <br />placed along the edge of the embankments. Immediately after construction is complete <br />the area disturbed will be seeded and mulched to promote a reduction in the rate and <br />volume of run-off. <br />Drainage <br />The bridge spanning East Salt Creek is on private property near Highway 139 has been <br />designed to safely pass the 100 year storm event, see Appendix M. The flood hazard <br />to the haul road is mitigated by adequate sizing of culverts. This is the subject of a <br />separate report by R. V. Lord and Associates in Appendix M(i). The Lord study does <br />not address the 72" culvert where the haul road crosses over Munger Creek. This <br />culvert must pass the 10-year event which is 225 cfs, see Table 4.5-6. With a HW/D <br />ratio of 1.25 this 72" culvert has the required capacity (ref. Handbook of Steel Drainage <br />& Highway Construction Products). A HW/D ratio of 1.25 means water must pool 18" <br />above the top of the culvert in order to pass the design flow. <br />• The haul road from State Highway 139 to the gob pile will be maintained in accordance <br />Reclamation <br />with Rule 4.03.1(6). The road surface will be periodically watered and maintained with <br />a motor grader. Gravel will be added to the road surface as necessary. Ditches along <br />the roadway will be periodically cleaned with a motor grader and the road shoulders will <br />be smoothed. If the haul road is damaged by a catastrophic event such as a flood or <br />earthquake, it will be repaired as soon as practicable after the damage has occurred. <br />See Section 3.9.1, Backfill and Grading -Lower Road. <br />r~ <br />LJ <br />M" 2.2-7iii 9/02 <br />