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Qllalificationfc}r the Colorado Water Conservation Board ~- planned ecosystem restoration, cultural, and transportation projects. These projects would be constructed in the former floodway and backwater effects could not be mitigated, so the community decided to revise its floodway instead, Because the entire 100'year flood is contained within the channel of Clear Creek, the community decided that it could raise the BFEs throughout the length of the stream to allow additional development within the stream corridor, and no increased risks would occur to neighboring properties. A portion of the hydraulic data submitted as part of the CLOMR was a replicate of the original HEC-2 hydraulic computer model. No readable copy of the original input data exists. A replicated effective model was created and used as the base condition model for the CLOMR request. A pro- posed condition model, with the proposed bike path and the channel restoration, was constructed to compare the proposed floodway elevations with the FEMA flood way elevations at key cross- section locations along the stream's reach, Years Performed: Client: 1997 to Present City of Idaho Springs 1711 Miner Street Idaho Springs, CO 80452 Contact: William Macy, Mayor (303) 567-4421 Union Pacific Railroad Hydraulic and HlIdrologic Studies and FEMA Flood- plain Permits. The Union Pacific Railroad (UPRR) Engi- neering Division utilizes ES to provide hydrologic and hydraulic design engineering services in its annual bridge replacement and track construction programs throughout their U,S. operating region, Parsons lOS's project manager originally devel- oped the current UPRR criteria used for sizing waterways at bridge openings, The UPRR has subsequently used the criteria to size the water- ways at over 10,000 bridges so that they conform to local and state FEMA regulations for impacts to lloodplains, i__ __i Accurate llood hazard assessment at each UPRR bridge replacement is important because many of the w3terway openings are changed from existing conditions, and risks to all properties need to be reliably established before the action is taken, Parsons ES has automated a procedure of systematically testing alternative bridge waterway sizes to quickly and ,xonomically select the opti- mal size for each river or stream crossing, Parsons ES conducts these watcnvay analyses for about 250 bridges per year in most of 22 west- ern and central states, Each site is visited by a Parsons ES engineer and survey crew. where cross-section survey data is collecled. localllood- plain administrltors are contacted, and office cal- culations are made 10 provide the UPRR with waterway opening information for the replace- ment bridge. All of these studies to date have heen com- pleted by Ihe engineers proposed for the CWCB reviews, The resulls of each analysis are included in a report which includes descriptions of site conditions, llocd flow rates, hydraulics of the ex- isting slructure, presence of Clapped FEMA floodplains. hydraulics of the replacement stmc' ture, impacts on backwater and existing mapped floodplains of the proposed replacements. dimen- Slons of the proposed replacement opening, and results of contacts with local and slate require, ments regarding t100d plain development permits and environmental for each site. During each calendar year. the UPRR also de- signs and const '\lcts numerous caracity expansion projects, involving construction of new second or third tracks alongside their existing tracks. These new tracks cress numerous stre3.rns and rivers, many of which are in FEMA.mappecl tloodplains and involve pla2ement of fill in floodplains, Par- sons ES performs hydrologic and hydraulic stud- ies of the combined effects of fill and bridge modjfications. rn-17Sl).doc 1-6 ~PARSDNS !!!!!'--_I_- --