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  <br />6    <br />  <br />The consultant shall use the hydraulic model to identify hydraulic conveyance improvements <br />that are required for the McElroy Road crossing. On December 13, 2021, the McElroy Road <br />Bridge collapsed during a flood. Local and state authorizations were granted to re-installed the <br />bridge for temporary use with the stipulation that permanent solution will need to be found. <br />Sufficient flood conveyance is required to ensure that the crossing provides reliable access to <br />emergency responders and evacuation of residents during floods. The consultant shall use the <br />hydraulic model to identify, at a conceptual level, the size of waterway that will be required to <br />provide reliable access and meet local and state hydraulic requirements. <br />Deliverables: <br /> Figures showing the impact each bridge has on velocity, depth, water surface elevations <br />and inundation limits. Figures will be produced for up to three of the five floods. <br /> Figure showing the approximate size of the hydraulic opening required for the McElroy <br />Road bridge. <br />Assumptions: <br /> The results of the bridge evaluation will be presented at the same meeting as the model <br />results in Task 2.3. The meeting is included in Task 3.1 below. <br /> The McElroy Road bridge waterway will be presented as a conceptual sketch intended <br />to provide the community and County with a general understanding of the length and <br />height of the new crossing that will be required to provide reliable access and meet local <br />and state regulatory requirements. No civil, structural or geotechnical design activities <br />will be performed. <br />2.5 Geomorphic Assessment <br />The consultant shall conduct a geomorphic assessment to: <br /> Identify and describe the geomorphic processes that currently shape the project reach <br />and how human modifications (flow regulation, levees and revetments, bridges, etc.) <br />alter those processes. <br /> Identify past hydrologic events have been responsible for generating significant <br />geomorphic change to describe the relationship between flow and the historical <br />geomorphic evolution of the reach. <br /> If needed, depending on migration since the last channel migration zone assessment <br />and the extent of that assessment, measure the rate of historical channel migration <br />within and surrounding the project reach to determine typical channel migration rates, <br />patterns, and controls, if possible, to inform an assessment of channel migration hazard. <br /> Assess historical aerial imagery, LiDAR, geologic map data, and field observations to <br />determine the prevalence and typical character of avulsions within the project reach, <br />including the influence of large wood. <br /> Interpret hydraulic model outputs to inform channel migration and avulsion hazard <br />assessments. <br /> Map potential avulsion pathways through the floodplain to identify specific potential <br />avulsion risks.