Laserfiche WebLink
October 4, 2022 C-1981-019/Colowyo Coal Mine ZTT <br /> discharge into Reach 2 at the time of the inspection(Photo 2).Approximately halfway down Reach 2,the <br /> beginning of sinusoidal cutting was observed and extended for the remaining portion of the ditch into stock tank <br /> EP1 (Photo 3). Water flows collected rip rap from Reach 2 and pushed it down into EP1 where it settled(Photo <br /> 4). EP1 held minimal water as it is drained by a trickle tube culvert. The culvert was clear of debris and functional. <br /> A similar sinusoidal cutting pattern was observed throughout the entire length of Reach 1 of the FEPD(Photo 5). <br /> Along the upper portion of Reach 1,water flows pushed collections of rip rap which clogged and backed up within <br /> the ditch incrementally.Approximately two-thirds of the way down Reach 1 of the FEPD,maj or cutting occurred <br /> along a steep section(Photo 6).The depth of the cut was approximately 10 feet.The rip rap in and underlining <br /> gravel and soils were pushed down to the intersection of the FEPD and the South Collection Ditch(Photo 7 and 8). <br /> The majority of rip rap backed up and settled at this intersection. Sediment and small diameter rock(6"or less) <br /> flowed down the collection ditch before settling at shallower sections of the Collection Ditch. <br /> Water was observed to have breached and leave off-site at the intersection of the FEPD and the South Collection <br /> Ditch as well as 3 -4 other sections along the South Collection Ditch where sediment and rocks had settled(Photo <br /> 9 and 10).The drainage below the ditches was inspected and no signs of rip rap leaving the site was observed. The <br /> base of the drainage at intersection of Highway 13 saw erosion and cutting prior to the box culvert below the <br /> highway. It was unclear how much of the erosion was caused by this storm as it was previously eroded from a <br /> storm event that occurred in 2018. Sediment and small rock (—6"or less)plugged the box culvert below Highway <br /> 13 to approximately 3/4 full at the inlet(Photo 11). The outlet of the box culvert had about 6"— 1' of sediment and <br /> was not clogged(Photo 12). The majority of sediment bottle-necked at the inlet and backed-up along the natural <br /> drainage.There was no sign of water or sediment going over the top of the highway. Sediment and rock deposition <br /> was observed on the neighboring property leading to the Good Spring Creek(Photo 13). Colowyo had a meeting <br /> with the landowner prior to the inspection but the details of that meeting were not divulged.After the inspection, <br /> the Division gave Colowyo the go-ahead to conduct cleanup at the landowner's property and culvert. <br /> The North Trib.,East Pit Ditch and the Prospect Ditch were also inspected. These ditches are located just north of <br /> the FEPD and contribute runoff to the Prospect Pond from the Prospect Drainage.These ditches and their <br /> associated stock tanks were stable with no erosion or damage and remained stable. The Prospect Pond was also <br /> inspected. The pond held water at the time of the inspection and was discharging (Photo 14). Colowyo <br /> representative stated that the emergency spillway was engaged during the storm event. The emergency spillway <br /> showed no signs of major discharge or damage from water leaving the spillway(Photo 15).The Prospect Pond <br /> remained stable and both the primary and emergency spillway functional. <br /> Number of Partial Inspection this Fiscal Year: 3 <br /> Number of Complete Inspections this Fiscal Year: 1 <br /> Page 3 of 20 <br />