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Show Planning Underway to Replace Destroyed Mill Creek Bridge A combination of two major factors resulted in the failure of the newly-competed Mill Creek bridge across Mill Creek near Hecla Subdivision, it was reported this week by Blaine J. Kay, Director of the Utah Department of Transportation, after the review of reports from engineers and hydrologists Monday. - The first and probably biggest fac-nas fac-nas a record flood which measured as running approximately 5,600 second feet i water.. The bridge was designed, wording to Mr. Kay, to withstand a "fifty year flood," which was calculated , . it 5,200 second feet. The second big factor which caused the Mrth footing of the bridge to become: undercut, was the failure upstream of faty-year-old CCC check dam, which Wged in the stream just above the Mill Creek bridge, causing extreme turbulence turbu-lence and cavitation which washed out Ike footing and collapsed the bridge. Mr. Kay stated that the bridge had ten redesigned from its original Mcept, due to limitations on right-of-ny, and limitation of funds. A 30 degree 'slew" in the original design was later ttaged to 50 degrees, which had the (Sect of reducing the effective length of A structure. Originally planned gabion i (wire baskets filled with crushed Kk placed in a wall) was discarded for ftk rip-rap around the footings in an "tempt to make the ' design fit the I mJable city and coutny Collector Road todget, he said. Mr. Kay stated that his engineering I Hiffhad unanimously recommended 'J'inst attempting to repair the I ire. "The beams have all failed and j J heir integrity," he said, indicating I mi it would be impossible to determine a safe loading factor for them if they were used again. Cost estimates on repairing the damaged structure are almost as expensive as total reconstruction, too, he indicated. He said that his department was preparing new plans and specifications specifica-tions for a replacement structure, which would be considerably longer, and which would be built on concrete caisons poured on large pedestals constructed far below the flow line of Mill Creek. Estimated cost of the new structure, including removal of the damaged, material, is around $150,000... , . . The Utah Department of Transportation Transporta-tion staff is currently investigating the possibility of using Federal Highway Admiriistraton "off-system" funding for the bulk of the cost of the new structure, Mr. Kay stated. FHWA officials have been contacted and have indicated that these funds could probably be used on the structure if programmed by the Utah Transportation Commission. Utah Transportation Trans-portation Commissioner Sam Taylor of Moab, who represents eastern Utah on the five member commission, stated that the body is meeting in regular session this Friday at Bryce Canyon, and he would urge the Commission at that time to program funds for the projet. Matching funds (around 10 percent of the total cost) would have to be raised locally. Grand County Commission Chairman D. L. Taylor stated Tuesday that the Commission Commis-sion was meeting next Monday to amend the current budget, and if specific numbers on funds required for matching purposes are available at that time, the Commission will consider the matter Monday. ' If funding arrangements can be worked out between the Utah Department of Transportation and Grand County during the next week, the project will probably be advertised for construction before the , end of August. The project will, however, take the winter to build, so traffic will be detained at that point for some time. Commissioner Taylor stated that Grand County is planning on the construction of a temporary crossing, using a culvert, so that school and other traffic will not be forced to detour the structure all winter. |