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E-9 <br />prepare the RICACES cost estimate. This means that at least a modest amount of P I <br />effort after feasibility is expected to further develop the design of the project feature <br />The cost to administer a PED phase is not included for the feasibility study but will <br />co-f.sidered irjw-&w%wm& m-s-okwai Cost estimates in the future. <br />H�*WQVV and UVftylics: <br />Vvdroloav — E.YiSfiTH COTditioy-n <br />Subdivide the 6 Blanco River sub -basins at locations of interest for additional detail of <br />peak flows and hydrograph timing. Add Bypass Creek and San Marcos subareas <br />downstream through Martindale development. Input updated Mod Puls routing data into <br />HEC -HMS model. Develop Muskingham-Cunge 8 -point routing for basins not <br />encompassed by the hydraulic model. Calibrate HEC -HMS model to the May 2015 event <br />with updated NWS rainfall and re -calibrate to previous historic storms. Reconcile <br />hydrologic models to ensure Blanco and San Marcos River flows correlate with adopted <br />FEMA flood recovery frequency flows at Wimberley and Kyle. Perform 8 standard <br />frequency runs to develop standard frequency discharges. <br />R-ydraulies — Existing conditions <br />Update hydraulic model. Clean up the multiple Blanco River geometries in the area of <br />San Marcos (steady, unsteady, 3 overflow areas). Develop new existing conditions RAS <br />�*[$] dil-)IBMVA NT -4M] 4ircxs Model as a base, Extend RAS <br />model downstream through Martindale and i Creek confluence. Develop <br />updated Modified PULS routing sections, where possible, to correspond with revised <br />Blanco sub -basin. Calibrate model to May 2015 event high water marks in both the <br />Wimberley area as well as San Marcos area with flow splits. Develop 8 standard <br />frequency flow runs, using unsteady to determine flow splits and timing. <br />Alternatives Analysis <br />Optimize Bear Creek detention sizing to significantly reduce flood damage and loss of <br />life along the Guadalupe River in New Braunfels. Includes testing spillway sizes for <br />multiple dam heights and preparing data for economics. Optimize Blanco 2 detention <br />sizing to significantly reduce flooding and loss of life along i River and analyze <br />impacts in Wimberley and San Marcos. Includes testing spillway sizes for multiple dam <br />heights and preparing data for economics. Analyze and size a diversion structure to <br />divert enough flow from the Blanco River to reduce flooding within San Marcos. This <br />analysis will also investigate and mitigate upstream impacts. May include sizing a levee <br />upstream. Model Bypass Creek channelization to determine channel size necessary to <br />convey diverted flow. Analyze confluence of San Marcos River and Blanco River to <br />determine extent of flooding due to San Marcos River only. Develop a calibrated 2D <br />HEC -RAS model of the San Marcos/Blanco River area to evaluate flooding and <br />M-1 <br />