2004-08-04_REVISION - M1978056 - Laserfiche WebLink

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demonstrate that the proposed mining and reclamation plan will comply with the requirements of Rule 3.1.6, ie: 1) minimize disturbances to the prevailing hydrologic balance of the affected land and of the surrounding area, 2) result in a flood control dike/north shoreline that will not damage adjoining property or conflict with water pollution laws, rules or regulations of the federal government, the state of Colorado or with any local government pollution ordinances, and 3) result in a flood control dikelnorth shoreline that is stabilized and protected so as to effectively control erosion. In response, the Division requests that VCI provide any relevant and available floodway designations for the reach of the Cache La Poudre River in and near the Durham Pit. Such flood way designations) whether current or old should include floodway boundaries, base flood elevations, date(s) of designation, and the authorizing federal and/or state organizations). The Division also requests that YCI provide any available maps and/or photographs showing the extent, elevation, and condition of the flood control boundary along the south bank of the Cache La Poudre River at the time of submittal for the original permit application, ie: February 28, 1978. Please provide. Please refer to memorandum and related attachments of 6 July 2004 from Anderson Consulting Engineers. 28. Existing Flood Control Dike: VCI has specified that they are retaining all aspects of the original application that apply to Floodway or Floodplain considerations, as part of the Amendment, or any subsequent revision. The current permit specifies that 100% of the Durham Pit lies within the Intermediate Regional Flood Zone and 97% lies within the Standard Project Flood Zone as reported by the US Army Corps of Engineers in their report of March, 1974, prepared for the Latimer-Weld Regional Planning Commission. The current permit also specifies the following with respect to the flood control dike along the south bank of the Cache La Poudre River. "The dike will be considered approximately 100 feet wide as measured from the top of the river side of the dike to the toe of the dike on the lake's edge. The dike will be raised to a point aproximately 9 feet above the bed of the Cache La Poudre River. The top of the dike will be approximately 30 feet with the slope toward the lake at approximately 5: ] . The dike on the river side will be 2:1. The dike will be seeded in the first appropriate season following its completion. The river side of the dike will be riprapped with broken concrete and other suitable material. The interior portion of the dike will also be re-inforced with similar material before being covered with overburden and topsoil. Based on these conditions, the Division requests that VCI provide a detailed survey of the Cache La Poudre River for the reach that bypasses the Durham Pit. The survey will need to include a longitudinal profile of the thalweg of the river, and representative cross sections that extend from the north bank of the river to the bottom of the pit north slope or edge of berm, whichever is farther. The survey will also need to include the 9 feet above the thalweg elevation along the existing flood control berm and define the volume of berm material to be removed (excess) or the volume of berm material left to be constructed. In addition, the Division requests that VCI provide designs, plans, and details for completing the backfilling and grading and slope Varra Companies, Inc. M1978-056 Durham Sand & Gravel Pit - 2003 Amendment -Friday 23 July 2004 reply to correspondence Gom the Colorado Division of Minerals and Geology of 9 June 2004.