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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 />Photo 2651 shows the upper portion of the steep "B" segment. Photo 2652 shows the lower segment of the <br />diversion leading into Sediment Pond 9, as well as the flow path from the ditch breaches parallel to the left side <br />of the lower ditch segment. Photos 2654 and 2655 are a gullied section along the upper segment of Diversion <br />Segment "B". This gully segment was adjacent to the end of the upper terrace drain, was approximately 30 feet <br />in length, 2-3 feet wide, by 4 to 8 feet deep. There was an additional gully segment approximately 2-4 feet deep <br />extending 40' or more, beginning in the vicinity of the lower terrace drain (Photo 2660). Interim repairs had been <br />completed along this ditch segment, but it appeared that breaches may have occurred both above and below the <br />lower gullied segment. Apparent breach locations are evident in Photos 2656, 2657, and 2658 (downhill view), <br />and 2661 (uphill view). Photos 2662 through 2666, and Photo 2699 show sediment deposition downstream of <br />the breaches, in the vicinity of the Pond 9 emergency spillway outlet. Photo 2702 shows the inlet end of the <br />adjacent Dept. of Transportation (DOT) culvert that runs beneath I-70, to the Colorado River. Sediment, <br />including some coaly material and rock, but mostly soil material, was deposited up to a foot or so thick in the low- <br />lying area below the Pond 9 embankment, extending down to the DOT culvert inlet. <br />The affected segment of the RSRDA Upper Diversion will need to be restored to design condition from a <br />point just upstream of the canyon drainage confluence, down to the Pond 9 inlet. This work was in <br />progress at the time of inspection. Sediment and debris will need to be pulled away from the DOT <br />culvert inlet. Pond 9 primary discharge outlet could not be located, and may have been covered by <br />sediment or debris; it will need to be uncovered if this is the case. Areas disturbed by ditch <br />maintenance, sediment deposition outside of the sediment control system and associated maintenance <br />will need to be seeded. <br />The RSRDA North Perimeter Collection Ditch and adjacent areas were also affected by the storm runoff. Flow <br />down the light use road below the Upper Diversion Ditch culverted crossing runs down to a small sump area and <br />into a 6" flexible ADS pipe, into the North Collection Ditch, and then into Pond 8. It appears that runoff down the <br />short road segment overwhelmed the capacity of the flex pipe, poured over and washed out the berm behind the <br />pipe inlet, and washed down the steep coaly slope along the flex pipe down to the North Collection Ditch. Flow <br />down the steep coaly slope scoured a gully up to 8 feet deep down the slope, and deposited rock and coaly <br />debris along most of the length of the North Collection Ditch down to Pond 8. The eroded slope will need to <br />be repaired, berm rebuilt and sump excavated, flex pipe repaired as necessary, and the affected <br />segment of the North Collection Ditch restored to design condition. Photo 2672 shows the flex pipe inlet <br />sump area and berm; 2670 and 2671 show closer views of the breached berm that resulted in gully; 2669 is a <br />close up view of the gully from the toe of the steep slope, 2668 is view downstream along the impacted segment <br />of the North Collection Ditch; 2673 is a more distant view of the gully and impacted segment of the North <br />Collection Ditch. <br />Pond 9 apparently did not discharge although there had been significant inflow of water and sediment. Water <br />level at the time of the inspection was approximately 4" below the inlet level of the primary discharge pipe. <br />There had also been inflow to Pond 8, but capacity had not been significantly affected. At the time of inspection, <br />bottom of Pond 8 was muddy with shallow puddles. <br />CRDA-2 Refuse Disposal Area <br />For the most part, CRDA-2 drainage structures functioned effectively, in that storm flows were diverted away <br />from the waste pile, and terrace drains conveyed runoff from the reclaimed slopes off the pile to perimeter <br />ditches and ultimately into Sediment Pond 10. However, heavy flows down the steep barren slopes above the <br />CRDA-2 Upper Diversion resulted in significant sediment deposition along the ditch, in places completely <br />5 <br />