Laserfiche WebLink
RULE 2 PERMITS <br />In this regard, and depending on site-specific opportunities, Colowyo will utilize the planned post - <br />mine topography (PMT) to help identify candidate (and prime candidate) areas for targeting <br />Sagebrush Steppe post -mining communities. Key to this analysis will be considerations for the <br />risk of erosion and for long-term stability. One such "threshold" value to be used for this analysis <br />will be a slope break at 10% gradient. Slopes greater than 10% will be considered too risky to <br />make attempts at targeting shrub communities, largely due to snowpack runoff scenarios that can <br />often lead to serious erosion and stability failures. For example, snowmelt runoff in the early <br />1980s caused widespread and severe down -cutting of the natural drainages to the immediate west <br />of Colowyo. Unless proven otherwise by hydraulic and/or erosion modeling, slopes less than 10% <br />will be identified as candidate locations for shrub community establishment. Another "threshold" <br />value to be used in the PMT analysis is the size of units that may exhibit slopes 10% or flatter. <br />Areas small in aerial extent (e.g., less than about 5 acres) will not be identified to receive shrub - <br />conducive metrics. Only those areas that are larger will be identified. The exact size cutoff will <br />be at the discretion of the reclamation coordinator, however, a practical limitation must be defined <br />given the complications realized by the change in revegetation targeting measures. <br />Where Sagebrush Steppe revegetation will be targeted, Colowyo would apply shallow lifts of <br />topsoil (< 6 inches, ideally 4 inches). Where ideal spoil conditions are encountered, special effort <br />will be made to place very minimal topsoil layers (nearly zero). The size of these areas must be <br />small in order to ensure the potential erosion potential created by this activity does not negatively <br />impact areas down slope. It is imperative for the Division to grant a substantial amount of latitude <br />to Colowyo in the first several years of the implementation of the new reclamation plan as this will <br />be a learning process for all parties involved. The Division will be informed of any instances of <br />"nearly zero" topsoil laydown areas prior to or during topsoil laydown activities to ensure that the <br />Division has the opportunity to verify Colowyo is adequately managing erosive potential. In most <br />cases, due to the general rockiness of Colowyo's spoil, a layer of topsoil is desirable in order to <br />limit damage to the preferred seeding equipment that will be utilized wherever possible in these <br />areas, as proper seed depth placement is a major factor when establishing shrubs. To help maintain <br />topsoil replacement balances, thicker lifts of topsoil (> 6 inches, occasionally up to 3-4 feet) can <br />be placed along the groin of opposing slopes (drainage -ways). On long slopes steeper than 10%, <br />topsoil distribution using pushdown techniques may be altered to facilitate thin layers near the <br />upper shoulders of the slope, with thicker layers near the bottoms. In this manner, the lower <br />elevation areas that tend to catch more snow will receive and store greater quantities of moisture <br />with the hope that some of the mountain shrub seed within the seed mix will be presented with <br />enhanced opportunities for growth and development, especially taxa such as snowberry. The <br />shoulders of the slope, where soil thickness has been reduced will present greater opportunity for <br />sagebrush to develop given reduced competition from cool -season grasses. In order to facilitate <br />proper accounting of the topsoil resource, topsoil placement on specific areas will be tracked by <br />load counts of the equipment involved. In cases where only Sagebrush Steppe acres are reclaimed <br />in one season, replacement volumes may be less than the currently approved 8 -inch average (in <br />the original permit area, approximately 20 inches in the South Taylor area). This does not cause <br />undue harm on the resource as the "left over" material will be utilized in the development of deeper <br />soil areas elsewhere in the reclamation progression. All activities will be accurately and fully <br />described within the confines of the Annual Reclamation Reports that include topsoil balance <br />tracking. <br />Rule 2 Permits 2.05-29 Revision Date: 5/25/18 <br />Revision No.: RN -07 <br />