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August 24, 20 10 C-1981-019/Colowyo Coal Mine JRS 497:?7 <br />the ditch was found to be constructed in the correct location. Finally, the ditch construction was compared with <br />the design requirements in Exhibit 7-14G. The approved designs call for a ditch with a 10 foot bottom width, 3:1 <br />side slopes, a depth of 1.7-1.8 feet and riprap with a D5o ranging from 9-18 inches. The on-the-ground <br />measurements showed that the ditch had a bottom width of approximately 20 feet, side slopes that were <br />approximately 3:1 and a depth ranging from approximately 3-5 feet. The riprap in the bottom of the ditch <br />conformed to the required D50 sizing of 9-18 inches. In addition, the side slopes of the ditch were armored with <br />larger riprap. No problems were noted with side-cutting along the length of the ditch and it appears as though the <br />ditch has reached an equilibrium at this point. Water from the drainage area was able to flow into the ditch either <br />on its own or through a series of contour ditches that intercepted the Gulch A Ditch. Since this ditch will still <br />receive runoff from an area that is not included in the Phase I, II or III Bond Release area (a small portion of the <br />Gulch A watershed to the southeast), the Division will be excluding the ditch from the SL-04 and SL-05 Bond <br />Release applications. The exclusion area for the Gulch A Ditch is approximately 6.9 acres. <br />- The Section 11 Ditch conveys flow from a small portion of the Gulch A watershed from the Phase III Bond <br />Release area and discharges into the Gulch A Pond. The entire Section 11 Ditch is within the Phase III Bond <br />Release area. The ditch was walked in its entirety, from station 0+00 to station 11+91. Elevation readings were <br />taken at locations along the ditch and compared with the design profile shown on Map 33. The attached data and <br />cross-section show that the elevation of the ditch, as constructed, matches that of the design from Map 33. The <br />ditch location was also compared with the permitted location shown on Map 41 and the ditch was found to be <br />constructed in the correct location. Finally, the ditch construction was compared with the design requirements in <br />Exhibit 7-14G. The approved designs call for a ditch with a 10 foot bottom width, 3:1 side slopes, a depth of 1.7 <br />feet and a vegetative lining. The on-the-ground measurements showed that the ditch had a bottom width of <br />approximately 15 feet, side slopes that were approximately 3:1 and a depth ranging from approximately 3-4 feet. <br />The bottom of the ditch was well vegetated and there was some small rock that has washed into the ditch and has <br />helped to protect it. In addition, the side slopes of the ditch were armored with larger riprap. No problems were <br />noted with side-cutting along the length of the ditch and it appears as though the ditch has reached an equilibrium <br />at this point. Water from the area was able to flow into the Section 11 Ditch. The Section I 1 Ditch will be <br />included in the Phase III Bond Release. <br />- The Southeast Tributary to Streeter Ditch conveys flow from center of the Streeter watershed area of the East Pit <br />Phase III Bond Release area and discharges into the Streeter Gulch Ditch and ultimately the Streeter Pond. The <br />entire Southeast Tributary to Streeter Ditch is within the Phase III Bond Release area. The ditch was walked in its <br />entirety, from station 0+00 to station 36+50. Elevation readings were taken at locations along the ditch and <br />compared with the design profile shown on Map 33. The attached data and cross-section show that the elevation <br />of the ditch, as constructed, matches that of the design from Map 33. The ditch location was also compared with <br />the permitted location shown on Map 41 and the ditch was found to be constructed in the correct location. Finally, <br />the ditch construction was compared with the design requirements in Exhibit 7-14E. The approved designs call for <br />a ditch with a 10 foot bottom width, 3:1 side slopes, a depth of 2.8 feet and a vegetative lining. The on-the-ground <br />measurements showed that the ditch had a bottom width of approximately 15 feet, side slopes that were <br />approximately 3:1 and a depth ranging from approximately 3-5 feet. The bottom of the ditch was well vegetated <br />and there was some small rock that has washed into the ditch and has helped to protect it. In addition, the side <br />slopes of the ditch were armored with larger riprap. No problems were noted with side-cutting along the length of <br />the ditch and it appears as though the ditch has reached an equilibrium at this point. Water from the area was able <br />Number of Partial Inspection this Fiscal Year: 3 <br />Number of Complete Inspections this Fiscal Year: 0 <br />Page 7 of 39