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~; 5. Review of the )`lining Plan Map, Exhibit C-3 indicates a potential concurtent wetland mitieation area of approximately 13.9 acres immediately south of Cell 3. The applicant also states that the full extent of 404 jurisdiction and mitigation requirements is not known at this time. The Division requests that the applicant keep the Division apprised of any 404 permitting requirements. Also, any wetlands construction. enhancement, or mitigation that will occur within the 210 acre permit azea will be subject to the requirements of the Constntction Material Rules and Regulations. Under that scenario, the Division will be requesting the applicant/operator to submit an approvable plan for site grading and wetlands revegeta[ion. Please respond. 6. Review of the Mining Plan Map, Exhibit C-3 indicates that the applicant has proposed to mine in Cell 4 within I ]0' of the west bank of the Big Thompson River. A significant portion of Cell 4 is also within the floodplain (?]00-year?) of the Big Thompson River. The applicant also states [hat the 110-foot offset indicated on Exhibit C-3 is intended to keep the mining operation out of the floodway of the Big Thompson River, however [he location of the floodway has not been clearly defined and the applicant concedes that F.E.M.A. maps do not identify floodways in this area. In conformance with Rules 3.1.5(3), 3.1.6(1), and 3.1.6(3) and in order to ensure the s[mc[ural integrity of the river channel and in-pit s]opes throughout the life of the mining operation, the proposed mining plans will need to be revised to conform with the criteria listed in the Division's August 1998 In-Stream Aggregate Extraction & Reclamation Guidance Document. (Please see attached guidance document). The following options are acceptable [o the Division: Option A: The applicant may revise the mine plan map to show the boundaries of the "floodway" of the. Big Thompson River and cleazly show that all mining will occur outside the floodway. In conjuction, the applicant should revise the narrative in the mine plan by providing a commitment to no extraction within [he floodway of the Big Thompson River. Since the F.E.M.A. studies for the Green/Croissant area do not show the location of the floodway, the applicant may develop and submit a hydrologic evaluation of the expected location of the floodway. However, supporting documentation and hydrologic assumptions must be included if this option is chosen. Option B: The applicant may revise [he mine plan and mine plan map to clearly demonstrate that no mining will occur within 400 feet of the west bank of the Big Thompson River. Option C: The applicant may keep the proposed 1 ]0' setback upon submission of an approvable plan and cross-sectional design for side channel spillways allowing for pressure equalization of floodwaters between Cell 4 and the channel of the Big Thompson River. For acceptable design criteria, please refer to the attached guidance document (Appendix D and Figure D-16). Option D: The applicant may keep the proposed 110' setback upon submission of an approvable plan and cross-sectional design for channel riprap slope protection and pitside riprap slope protection. For acceptable design criteria, please refer to the attached euidance document (Appendix D and Figure D-5, a) and c)). 6.4.5 EXHH3IT E -Reclamation Plan 10. The applicant had ajurisdictional wetlands delineation performed on [he Green/Croissant Property in July 2000 by Savage & Savage, Inc.. The results of the delineation indicate that jurisdictional wetlands account for 30.7 acres and waters of the U.S. account for 5.51 acres within the proposed permit area. Review of [he Reclamation Plan Map, Exhibit F shows a reclaimed wetland of 8.3 acres, a potential wetland enhancement area (also shown on Exhibit C as a potential wetland mitigation area) south of Cell