Laserfiche WebLink
- 3 - <br /> inside. If current use is light use, but future use is for access <br /> or coal haulage , unneeded width should be ripped and seeded. <br /> In either case, appropriate drainage control structures should be <br /> installed and maintained. In road segments where road ditches <br /> cannot be maintained, a combination of waterbars and outside berms <br /> may be appropriate, but the maintenance plan would need to address <br /> how snow removal would be accomplished without pushing berm <br /> material over the outslope. <br /> - On some light use road segments where surface rill erosion is a <br /> problem, waterbars or beltline surface water deflectors which would <br /> intercept road surface drainage , but not ditch drainage may be <br /> appropriate. <br /> Consideration should be given to replacing culverts which are <br /> subject to frequent clogging or abrasion with appropriately <br /> designed and outfall protected dips or low water crossings . <br /> Given the high maintenance nature of the Coal Basin road system, a <br /> specific commitment of time and resources to regular and post storm <br /> event inspection and maintenance is critical . Plans for snow <br /> removal which are practical , yet compatible with the goal of <br /> minimizing sedimentation from the road system should be developed. <br /> Locations for storage or disposal and stabilization of sediment <br /> from ditch or sediment trap cleanout need to be specified . <br /> With reseect to road width reduction , in most cases it should be <br /> accomplished by a combination of fill slope crest reduction and <br /> moving the drainage ditch further out from the cut slope . An <br /> exception would be upper segments of Road G which are characterized <br /> by well vegetated cut and fill slopes and which have experienced <br /> very little erosion. In such areas , the fill slope should not be <br /> disturbed . <br /> Problem: Excessive sedimentation to streams from road surfaces and drainage <br /> ditches ( see NOV C-91-017) <br /> Contributing Factors : <br /> Excessive ditch gradients , erosive velocities <br /> Culverts or ditch relief drains which divert large volumes of <br /> sediment laden runoff directly into water courses or onto steep, <br /> non vegetated slooes with little or no potential for any setting of <br /> sediment before the runoff reaches a live water course. <br /> Possible approaches : <br /> Riprap erosive ditch segments and/or install check structures to <br /> slow velocities . <br /> Provide additional ditch relief structures (culverts , waterbars , <br /> rolling dips) in locations where vegetation will provide some <br /> filtering of sediment. <br />