Laserfiche WebLink
Mr. Rick Siebel, Regional Director -7- <br />Office of Surface Mining <br />Western Region Coordinating Center <br />May 16, 1995 <br />of Starkville Gulch creates a meander pattern that is, for the most part, devoid of <br />convolutions, braiding or oxbows. As the permanent diversion has been reconstructed with <br />one small "s" meander where the diversion passes under the site access road, and with one <br />larger gradual meander near the west end of the permit boundary, the diversion both <br />approximates the premising configuration of Starkville Gulch's natural meander pattern and <br />blends with the undisturbed drainage above and below the diversion. <br />(d) As the diversion has no structural controls installed to impede waterflows associated with <br />the 100-year, 24-hour event, the entire diversion, including the culvert, is in dynamic <br />equilibrium with the drainage basin system. <br />(e) Due to the steep gradient of Starkville Gulch and the erosiveness of the natural soils in the <br />area, aquatic habitats are not known to have existed within the portion of Starkville Gulch <br />that lies within the Raton Creek permit boundary. The only water seen impounded within <br />Starkville Gulch is in areas upstream from the permit area where the landowner has <br />constructed small berms for livestock watering. As such, no aquatic habitats (described in <br />the State Regulations as generally a series of riffles and pools) have been constructed. This <br />is in compliance with Section 4.05.4(4)(c) of Colorado's regulations, which states, <br />"Establish or restore the stream to include a diversity of aquatic habitats...where <br />appropriate, that approximates the premising characteristics." <br />(f) Nothing in Section 4.05.4(4) prohibits the use of a culvert in the construction of a <br />permanent stream channel diversion. <br />The narrative in AFO's M-SEIR mentions maintenance liability concerns associated with the <br />culvert. EFMC has been apprised that they are responsible for maintenance of the culvert until <br />such time as final bond release is approved by the Division. The culvert has been in place since <br />1982. The Division issued an NOV in 1993 for failure to maintain diversion structures. <br />AFO's M-SEIR narrative also discussed that a portion of the culvert collapsed in 1994. This <br />occurred as a result of a fully loaded loader scraper passing over the culvert repeatedly during <br />reclamation operations last year. The repeated use of this type of heavy equipment over the <br />culvert is not likely to reoccur in the course of post-mining livestock grazing operations. <br />The Division believes that leaving the culvert in place will not create a geomorphology that <br />differs significantly from the premising configuration. Reference to a topographic map of the <br />surrounding area indicates the overall topography of the Starkville Gulch canyon ranges from <br />6800 feet at the ridge top to 6415 feet at the valley bottom. This is an overall elevation change <br />of 385 feet. Leaving the culvert does not impede the 100-year, 24-hour event, and adds only 12 <br />feet in "elevation" -the eight-foot culvert diameter plus four feet of overlying fill. This is a <br />difference of only 3% in the overall elevation change of the gulch. Additionally, the length of <br />the gulch is 7900 feet. The 675-foot long culvert comprises only 8.5% of the gulch's overall <br />