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ANALYSIS AND REC,OIMMENDATIONS <br /> Many of the Class 4 and 5 problems are related. Run-off from F-2 and 3 impacted F-9 <br /> and 11, and these impact F-20. F-25 thru 32 impact F-35 thru 38. These all have steep slopes <br /> were run-off from above generates speed and adds additional volumes of water to the next level. <br /> G-8 and 9 flows are most likely major contributors to G-18 and 19a problems for the same <br /> reasons. <br /> Outlet protection had mixed results. Pinned logs did very well when placed within a foot <br /> or less from the crest. Also,those that were longer in length did better than shorter logs. Those <br /> pinned logs that were farther down the slope did not fair as well. Water cut under or around the <br /> logs rendering them useless. Those pinned log dams that did the best were a combination of <br /> pinned logs and rocks. This combo held even when below I foot of the crest. <br /> Large rocks and other natural check dams did a fair job. Boulders at grade level did well. <br /> Large rocks did well so long as run-off was low or moderate. Areas of larger flows washed out <br /> around the rocks as one would expect. Trees and logsibranches did a fair job of slowing flows. <br /> Pinned hay bales did not fair well. Most were washed out or severely compromised. This <br /> was a surprise and I'm not sure if it was the bales or an improper pinning or installation. <br /> Many of the minor and easy fix erosion problems were caused by speed more than <br /> volume of run-off. Additional protection and flow inhibitors would help. <br /> From field observations I would like to submit the following recommendations: <br /> 1)Areas where steep slopes from above have major impacts need to be designed to slow water <br /> before crossing old roads. Use of a small bar ditch with several checkdams(log,rock or hay) <br /> could collect and slow water before it reaches rolled ditch. <br /> 2)Ditches should be staggered more on switch back roads. Ditches that were directly below <br /> other roll ditches had more erosion problems than those that are staggered. <br /> 3)Pinned log check dams should be located at the very crest. Those located beyond a foot of the <br /> crest had a substantially higher failure rate. <br /> 4)Pinned logs need to be longer. Several of these types of dam looked like they would have <br /> faired better if water had not washed around one end or another. Maybe a rough <br /> recommendation would be 2.5 times the width of the outlet. <br /> 5)In areas where potential is moderate to high for run-off flow, use check dams in roll ditch as <br /> well as at crest. Also,widen and slope ditch better. <br /> 6)In areas where major run-off will continue to be an issue, use larger rock to rip-rap outlets. <br /> These ditches might need to be reshaped to a broader, shallower drainage to disperse the <br /> volume better. <br /> 7)Use of multiple materials( logs and rocks) did the best overall. This could be an easy <br /> safeguard against minor and medium erosion problems. <br />