Transcript Document
Comprehensive Basinwide Protection Recommendations 13 Primary Principals: 1. Serve as framework moving forward 2. Establish acceptable levels of protection 3. Basin approach – multiple measures to accomplish 4. Uniform flood regulations and zoning 5. Goals for the reduction in flood flows 6. Reduce runoff rate and volume 7. Incorporate multiple purposes (FDR/NRE…) 8. Avoid or minimize adverse impacts 9. Cost effectiveness 10. RRBC to facilitate implementation of cross-jurisdictional partnerships where possible 11. Evaluation and prioritization of plan recommendations 12. Measure and evaluate implementation of the LTFS 13. Requires a shared responsibility and commitment • Part of Long Term Flood Solutions Report • Reduce Red River main-stem flows by 20% • Based on 1997 Spring Flood Event • Applied to HEC-HMS Synthetic Hydrology Lidar/Enhanced Technology RRBC-LTFS RRWMB Distributed Detention Plans ND Comprehensive Detention Plans • • • • • • • • Large Scale Sites Identification of all apparent sites WRD Involvement Multiple proposed conditions scenarios Multiple Runoff Events Establish benefit within Tributaries Establish reduction to Red River main stem Detailed reporting MN Expanded Distributed Detention Strategy • • • • • • • • Large Scale Sites Identification of sites required to meet LTFS goals Limited WD Involvement One proposed condition Standard melt progression event only Establish benefit within Tributaries Establish reduction to Red River main stem Generalized reporting 1. Guide WD project teams – Similar to BdSWD plan. 2. “Get FDR Projects in the Queue!” - State and Local Funding 3. Identify Project Concepts for Potential Federal Funding – Farm Bill 4. Consistency with On-going North Dakota Planning Effort 5. Potential Cost Share of FM Diversion Authority - $25 Million – Sites upstream of Halstad 6. Identify Sites for Halstad Upstream Retention Study (HUR) – RRBC Detention Site Identification •Project Planning Tool Incorporation •Watershed District/LGU Involvement •Upstream of local damage areas •Large Site Concepts (greater than 10 square miles – most in the 30 SM range) Detention Site Statistics •LiDAR Derived Elevation/Storage Data •LiDAR Derived Contributing Watershed •Consider construction/environmental impacts of gated pool elevations •Goal: 3” – 4” of gated storage per site (Meet LTFS Volume and Peak Goals) Hydrologic Analysis Benefits •Red River Basin HEC-HMS developed by the US Army Corps of Engineers •Incorporate Identified Detention Sites •Assume all gates closed •25, 50, 100-yr Rainfall (10-day) & 100-yr, 10-day Runoff (Snow melt progression included) •Existing conditions (Pre-1997) vs Proposed Conditions (Site Outlet, Damage areas, Reporting USGS Gages) •Watershed scale mapping only •Report Summarizing Analysis Red River Basin Commission Basinwide Flow Reduction Strategy Peak Flow Goal: 35% Reduction Peak Flow Obtained: 36% Reduction