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<br />III. Scope: <br />a. Assist Owner with developing a method of evaluating existing, planned, or potential <br />regional retention projects’ potential benefits to the Diversion Project. Scope to <br />include up to two (2) site evaluations. <br />b. Provide technical assistance to the RRBC in its study “Halstad Upstream Retention <br />(HUR) Modeling – Phase 1”. <br />IV. Deliverables <br />a. As requested. <br />H. PHASING PLAN INTERIM MODELING <br />I. Objective: Incorporate the Phase 1 and Phase 2 project features into the hydraulic <br />model, evaluate project benefits, and determine interim measures needed for a phased <br />project. <br />II. Background: The original project execution plan assumed unconstrained funding, an <br />approximate 8 year project schedule, and project design and construction starting on <br />the downstream (north) end of the project and progressing sequentially upstream. <br />Currently, it is anticipated that Federal funding will be constrained and, therefore, a <br />phased plan was developed to allow the project to proceed with limited Federal funding <br />and provide benefits as early as practical. This results in a three phased project. <br />Phase 1 includes the Diversion Channel from the Outlet to downstream of the Maple <br />River and associated bridges, in-town levees, and the Oxbow-Hickson-Bakke area levee. <br />Phase 2 includes the Red River and Wild Rice River control structures, the Staging Area <br />embankment, overflow embankment, tie-back levee, the Diversion Inlet structure, <br />staging area land, associated bridges and transportation improvements, and associated <br />mitigation projects. Phase 3 includes the Diversion Channel from the Maple River to the <br />Diversion Inlet structure, associated bridges, the Maple River Aqueduct, the Sheyenne <br />River Aqueduct, and associated mitigation projects. <br />There may be a lag of several years between completion of Phases 1 and 2, and the <br />completion of Phase 3, and, therefore, modeling and evaluation is needed to 1) <br />determine project benefits and 2) the need for and extent of temporary measures <br />between phases of the project. <br />III. Scope: Perform 100-year and 500-year modeling evaluations of Phase 1 and Phase 2 <br />project components, quantify interim benefits, and determine what interim measures <br />are needed until completion of Phase 3. <br />IV. Deliverables: <br />a. Draft Technical Memorandum. <br />b. Final Technical Memorandum. <br />I. PHASE 7.1 MODEL UPDATE <br />I. Task 1 - Update the Red River peak flow model geometry. Complete modeling for the <br />Red River peak flood events, including the 10-, 2-, 1-, 0.2-percent chance events and the <br />103kcfs and PMF flood events for both existing conditions and with-project conditions. <br />Geometry updates include: <br />a. Update storage connections for the existing and with-project model in the area <br />west of the diversion between the Maple River and the Sheyenne River to better <br />reflect floodplain impacts and diversion side inlet sizing. <br />HMG_TO9-A13_Long.docx 11 <br />DR <br />A <br />F <br />T <br /> <br />3/6 <br />/ <br />2 <br />0 <br />1 <br />5 <br />