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that all currently available and appropriate Floodway and Floodplain information for the affected <br />land and surrounding azea be provided and evaluated to the extent that the applicant can cleazly <br />demonstrate that the proposed mining and reclamation plan will comply with the requirements of <br />Rule 3.1.6, ie: 1) minimize disturbances to the prevailing hydrologic balance of the affected land <br />and of the surrounding azea, 2) result in a flood control berm 1 north shoreline that will not <br />damage adjoining property or conflict with water pollution laws, rules or regulations of the <br />federal government, the state of Colorado or with any local government pollution ordinances, and <br />3) result in a flood control berm /north shoreline that is stabilized and protected so as to <br />effectively control erosion. <br />In response, the Division requests that VCI provide any relevant and available floodway <br />designations for the reach of the Cache La Poudre River in and near the Durham Pit. Such <br />Fooodway designation(s) whether current or old should include Fooodway boundaries, base flood <br />elevations, date(s) of designation, and the authorizing federal andlor state organization(s). The <br />Division also requests that VCI provide any available maps and/or photographs showing the <br />extent, elevation, and condition of the flood control boundary along the south bank of the Cache <br />La Poudre River at the time of submittal for the original permit application, ie: February 28, <br />1978. Please provide. <br />28. The applicant has specified that they are retaining all aspects of the original application that <br />apply to Floodway or Floodplain considerations, as part of the Amendment, or any subsequent <br />revision. The current permit specifies that 100% of the Durham Pit lies within the Intermediate <br />Regional Flood Zone and 97% lies within the Standazd Project Flood Zone as reported by the US <br />Army Corps of Engineers in their report of Mazch,1974, prepared for the Lorimer-Weld <br />Regional Planning Commission. The current permit also specifies the following with respect to <br />the flood control dike along the south bank of the Cache La Poudre River: "The dike will be <br />constructed approximately 100 feet wide as measured from the top of the river side of the dike to <br />the toe of the dike on the lake's edge. The dike will be raised to a point approximately 9 feet <br />above the bed of the Cache La Poudre River. The top of the dike will be approximately 30 feet <br />with the slope towazd the lake at approximately 5:1. The dike on the river side will be 2:1. The <br />dike will be seeded in the first appropriate season following its completion. The river side of the <br />dike will be riprapped with broken concrete and other suitable material. The interior portion of <br />the dike will also be re-inforced with similar material before being covered with overburden and <br />topsoil." <br />Based on these conditions, the Division requests that the applicant provide a detailed survey of <br />the Cache La Poudre River for the reach that bypasses the Durham Pit. The survey will need to <br />include a longitudinal profile of the thalweg of the river, and representative cross sections that <br />extend from the north bank of the river to the bottom of the pit north slope or edge of berm, <br />whichever is farther. The survey will also need to include the 9 feet above the thalweg elevation <br />along the existing flood control berm and defzne the volume of berm material to be removed <br />(excess) or the volume of berm material left to be constructed. In addition, the Division requests <br />that VCI provide designs, plans, and details for completing the backfilling and grading and slope <br />protection measures (riprap) that will be used to stabilize the river and pit sides of the flood <br />control berm. Please address. <br />