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d. Conduct QA/QC review of the Phase 8 Existing conditions models for the RRN and tributary peak conditions. e. Conduct with-project modeling for the 10-, 20-, 50-, 100-, and 500-year events for the RRN peak flood event. f. Conduct with-project modeling for the 10-, 20-, 50-, 100-, and 500-year events for the tributary peak flood events. g. Conduct QA/QC of the Phase 8 with-project model runs. h. Prepare floodplain mapping for the 10-, 20-, 50-, 100-, and 500-year events for existing conditions and with-project for both the RRN and tributary peak flood events. i. Prepare draft and final Technical Memorandums summarizing Phase 8 modeling results. j. Conduct an independent QA/QC review of the unsteady HEC-RAS model. i. Part 1 – Conduct an independent QA/QC review of the Phase 7.1 unsteady HEC-RAS model geometry and general assumptions. Include a kick-off review meeting, a review of the technical memorandums and previous District Quality Control (DQC) and Agency Technical Review (ATR) reviews developed for the model updates subsequent to Phase 4, and a review of geometry files through Phase 7.1 of the model. Commence review following completion of the Phase 7.1 update. ii. Upon completion of the Phase 7.1 model review, provide recommendations for additional QC review of the Phase 8 model updates. iii. Document the review findings and recommendations in Technical Memorandum. iv. Document the review findings and recommendations in Technical Memorandum. k. Incorporate geometry and general assumptions QA/QC recommendations into the HEC-RAS model i. Review all comments and discus with USACE and review team, and determine which model recommendations should be incorporated into the HEC-RAS model. ii. Make revisions in HEC-RAS Model Geometry for Red (from Enloe to Perley), Wild Rice, Sheyenne and Maple Rivers: Update model to HEC- RAS 5.0, convert horizontal projection to Albers Equal Area. Update bridge modeling approaches, ineffective flow limits, bank stations, blocked obstructions, roughness parameters, river junction cross-section geometry, address ineffective flow at bridges and two inconsistencies between EX and WP models. Verify volume continuity. iii. Re-calibrate model using 2006, 2009, 2010, 2011 historic events (adjust parameters). l. Provide additional assistance to USACE for the Hickson Hydrology Update. These modeling tasks include assessing modeling parameters, development of a baseline storage-discharge relationships, comparison modeling downstream of the Otter Tail Diversion, historic flow record checks, and revise model calculation at bridges and inline structures. HMG_TO9-A13_Long.docx 15 DR A F T 3/6 / 2 0 1 5