Laserfiche WebLink
crosses over CR 22.5 and past the location shown on the FIRM map. With the channel <br /> extending past these two points, there is a factor of safety in the channel location that the <br /> channel will intercept the 100-year floodwaters passing over CR 22.5. <br /> Construction of the channel east of the railroad will require putting the Sterling No. 1 <br /> Irrigation Canal into a siphon under the channel. This will have the added benefit of <br /> limiting flows down the irrigation canal, which currently serves as a conveyance channel <br /> for floodwaters into the City of Sterling. Having the siphon will also help prevent canal <br /> spillage and break outs at uncontrolled locations. <br /> At the South Platte River, the channel will tie into the South Platte River channel bottom <br /> elevation. The channel will be widened and curved to direct the flood waters down the <br /> South Platte River. It is anticipated that the South Platte will backup into the channel <br /> when the South Platte has a high stage. <br /> X. IMPACTS AND PERMITS <br /> The City of Sterling applied for funding for this project through the FEMA Hazard <br /> Mitigation Grant Program (HMGP). FEMA is mandated by the Code of Federal <br /> Regulations (CFR) to comply with the National Environmental Policy Act (NEPA). <br /> NEPA requires that all federal funded projects have an environmental assessment <br /> conducted with an evaluation of alternative. An assessment of the environmental impacts <br /> for this project was conducted by URS Greiner Woodward Clyde for FEMA and <br /> compiled in a report titled, "Final Environmental Assessment, Pawnee Creek Flood <br /> Mitigation, City of Sterling, Town of Atwood, and Logan County, Colorado, FEMA- <br /> 1186-DR-CO, Project No. 0001" and was published in July, 1999. A copy of this <br /> document is located in Appendix 4. This document has been reviewed by FEMA and all <br /> applicable agencies with a Finding of No Significant Impact (FONSI) status given to the <br /> selected alternative. A copy of the letter from FEMA stating there are no impacts and a <br /> letter from FEMA to the City of Sterling relating this finding can be found in Appendix <br /> 5. P ,AA yLk. 4 A tLA ��� ,.�� - S�.� <br /> XI. COST EFFECTIVENESS <br /> Useful Life of Project <br /> With proper maintenance and operation, the proposed alternative is expected to have a <br /> life of in excess of 50-years. Substantial growth in the upstream basin, changes in land <br /> use, unexpected large sediment deposition, changes in weather patterns, changes in the <br /> highway and/or railroad crossings and overgrowth of vegetation in the channels could <br /> impact the life. For the most part, the impacts are items that can be addressed through <br /> on-going maintenance. <br /> 32 <br />