2012-02-01_REVISION - M2010049 - Laserfiche WebLink

Home Browse Search

Public Works Department The applicant's engineer, CGRS Environmental Services, submitted a FHDP application for review on August 8, 2011. The application was returned for more information on September 6, 2011. The application was resubmitted via email by the applicant's engineer on October 28, 2011 with a hardcopy received on November 7, 2011. Comments were returned to the applicant's engineer on October 28, 2011. The comments were addressed with a hardcopy submittal on November 17, 2011. The FHDP maps were stamped, signed, and dated by Randal Kenyon, P.E. # 41216. The FHDP application was submitted for a gravel mining operation known as the Great Western Sugar Quarry. The subject property is located north of 16 St and east of Ash Ave in part of the N1/2 Section 9 and part of the S1/2 of Section 4, T5N, R65W, Sixth P.M., Weld County, Colorado. Portions of the property are located in the Cache La Poudre Special Flood Hazard Area (SFHA), also known as the 100 -year floodplain and are designated as Zone A3 on Flood Insurance Rate Map (FIRM) Panel 080266- 0637C. A portion of the property is also designated as floodway on Flood Boundary and Floodway Map (FBFM) 080266 -0004. These designations indicate that there are published base flood elevations (BFEs) and floodway boundaries established for the Cache La Poudre River on the current effective FIRM dated September 28, 1982 and FBFM dated September 28, 1990. All FIRMs and FBFMs are prepared, distributed, managed, and revised by the Federal Emergency Management Agency (FEMA). The City of Greeley contracted with the Army Corps of Engineers (Corps) to update the floodplain and floodway boundaries. The Corps study resulted in a physical map revision that was adopted by FEMA. The Corps study will be incorporated as part of the DFIRM for Weld County. The Corps study is utilized by Weld County as the best available information. The subject property appears on Sheet 2 of 6 of the Corps work maps. The applicant's engineer did not provide a HEC -RAS model demonstrating the effect of mining on the 100 -year water surface elevations. The applicant and the applicant's engineer show that all stockpiles and buildings used in the mining process will be outside of the 100 -year floodplain. The applicant has placed a note on the final plat and on the FHDP drawing stating "No fill material (temporary or permanent) including but not limited to berms, material stockpiles, overburden stockpiles, or topsoil stockpiles shall be placed in the Poudre River Floodplain and Floodway that extend above the existing pre- mining topography." The applicant is hereby put on notice that if stockpiles are located in the floodplain above the existing pre- mining topography, an amended FHDP including hydraulic modeling shall be submitted for review and acceptance prior to the placement of such material. No material may be stockpiled in the floodway. There is an existing 41' x 39' foot wood and block barn located on the property in the 100 -year floodplain. The applicant has stated that the barn is a historic structure and will not be used for any mine processes. The barn shall not be remodeled or converted for mine uses unless an amended FHDP is obtained prior to the use of the structure. The applicant has indicated that the scale house and office will be located outside of the floodplain. If a scale house and office building are to be placed in the floodplain, an amended FHDP is required prior to construction and /or placement of the building. It should be noted that development activities located in a FEMA regulatory floodplain or floodway are subject to the requirements of Title 44 of the Code of Federal Regulations (CFR), Parts 60 and 65. The proposed sand and gravel operations will include a gravel pit, material stockpiles, overburden stockpiles, top soil stockpiles, conveyor, and on -site parking. Because more than 5 acres of land are being disturbed, FEMA in letters dated January 13, 2011 and June 17, 2011, informed the County that a Letter of Map Revision was required in order for Weld County to remain in compliance with Page 2 of 5 M. \PLANNING — DEVELOPMENT REVIEW\FHDP -Flood Hazard Development Permit \743 Varra Great Western Sugar Quarry\FHDP -743 Varra Great Western Sugar Quarry Conditional Approval 11 -21 -11 doc