Laserfiche WebLink
III. COMMENTS • COMPLIANCE <br />Below are comments on the inspection. The comments include discussion of observations made <br />during the inspection. Comments also describe any enforcement actions taken during the inspection <br />and the facts or evidence supporting the enforcement action. <br />channel, with gradient appearing to be within design limits and channel wider than <br />required. There are some problems with channel shape and riprap placement in various <br />locations along the segment between Ridgeline Road and 006-E2 confluence. Riprap <br />placement and subsequent equipment travel has resulted in a wide shallow channel, <br />with ridges or benns of mounded up along the outside edges of the channel. Rills have <br />developed to the outside of the berms, resulting in channel side-cutting and flow <br />bypassing the riprap. In some locations, the channel now resembles an elevated road, <br />with ditches on either side. See digital images 0177 through 0180. Image 0180 shows <br />the lower end of the segment at the E2 confluence. Just above the confluence, the <br />channel shape/riprap berms problem is particularly pronounced (left center of photo). <br />Riprap ridges need to be graded out to blend into channel side slopes to eliminate <br />sidecutting, and allow hillslope runoff to enter the channel. Lowest portion of the <br />channel bed should be in the center portion of the channel. <br />Lower Section (SS to D) <br />Design profile increases from approximately 8% at upper end to approximately 15% at lower <br />end, where Channel El ends at the 006 Gulch confluence. Design channel for the given slope <br />is trapezoid, with 2' bottom width, 7.5' top width, 11"depth, with 6" D50 riprap. <br />Observed channel appeared to be within the design gradient limits, width and depth in <br />excess of design requirements, adequate riprap, relatively stable segment. One problem <br />noted along this channel segment is a remnant temporary construction road that was not <br />adequately reclaimed. Flow concentration along the road remnant in the vicinity of the <br />power line crossing has resulted in a short gully on the slope segment between the road <br />and the channel. Digital image 0181 shows a segment of the road remnant adjacent to <br />the channel, associated ruts down to the channel, and a gully to the left of the ruts, <br />between the road and channel (right center of photo). The remnant road and <br />associated ruts and gullying need to be repaired (graded, scarified, and seeded as <br />appropriate). <br />006-E2 Channel <br />E2 is a relatively short, but very steep tributary to E1. Design profile increases from 3.6% near E1 <br />confluence to 36.5% in steep middle reach, decreasing to 10% at its upper end. Design specifications <br />for gradients up to 10% are fora 1.4' deep "v" shaped vegetated channel. Design for segments from <br />11 % to 40% specify a wide, shallow trapezoid channel (8' bottom width, 10' top width, 5" depth), with <br />gravel lining. <br />• Observed gradients appeared to be within design limits. Channel was actually trapezoidal along <br />its entire length, wider and deeper than design, with larger riprap than specified. The channel <br />appeared to be stable, with no apparent problems from the E1 confluence up through the steep <br />middle segment. <br />5 <br />