Detailed Survey Report Thief River Falls Flood Damage Reduction
Total Page:16
File Type:pdf, Size:1020Kb
Detailed Survey Report Thief River Falls Flood Damage Reduction Project and Improvem ent to Pennington County D itch #1 (Red Lake Watershed District Ditch #14) October 2010 Prepared by: HDR Engineering, Inc. 324 2nd Street East Thief River Falls, Minnesota 56701 DETAILED SURVEY REPORT THIEF RIVER FALLS FLOOD DAMAGE REDUCTION PROJECT AND IMPROVEMENT TO PENNINGTON COUNTY DITCH #1 RED LAKE WATERSHED DISTRICT DITCH #14 (PROJECT #171) October 2010 I hereby certify that this plan, specification, or report was prepared by me or under my direct supervision and that I am a duly Licensed Professional Engineer under the laws of the State of Minnesota. ______________________________________ Nathan P. Dalager, P.E. License Number 25309 HDR Engineering, Inc. 324 Second Street East Thief River Falls, Minnesota 56701 RED LAKE WATERSHED DISTRICT TABLE OF CONTENTS TABLE OF CONTENTS 1.0 INTRODUCTION ......................................................................................................................................... 1 1.1 PETITION ............................................................................................................................................................ 3 1.2 DITCH IMPROVEMENT PROCESS .............................................................................................................................. 4 2.0 PROJECT NEED .......................................................................................................................................... 5 2.1 PROJECT HISTORY AND PERFORMANCE ..................................................................................................................... 5 2.2 CONCERNS AND DESIGN ISSUES ............................................................................................................................... 6 3.0 PROJECT DESCRIPTION .............................................................................................................................. 8 3.1 ALTERNATIVES AND OPTIONS CONSIDERED ................................................................................................................ 8 3.2 SURVEYS ........................................................................................................................................................... 11 3.3 DATA COLLECTION .............................................................................................................................................. 11 3.4 ALIGNMENT & STATIONING .................................................................................................................................. 11 3.5 PLANS & RIGHT‐OF‐WAY .................................................................................................................................... 13 4.0 PROJECT DESIGN CRITERIA ....................................................................................................................... 14 4.1 DESIGN GOALS .................................................................................................................................................. 14 4.2 DESIGN CRITERIA ................................................................................................................................................ 14 4.3 HYDROLOGY ...................................................................................................................................................... 14 4.3.1 Design Storm Data ............................................................................................................................... 15 4.3.2 Design Rainfall Distribution ................................................................................................................. 16 4.3.3 Subwatersheds ..................................................................................................................................... 16 4.3.4 Peak Flow Rates ................................................................................................................................... 17 4.4 HYDRAULICS ...................................................................................................................................................... 17 5.0 RESULTS & ADDITIONAL CONSIDERATIONS............................................................................................... 25 5.1 IMPROVED DITCH CROSS‐SECTIONS ....................................................................................................................... 25 5.2 IMPROVED DITCH GRADES ................................................................................................................................... 26 5.3 CULVERT IMPROVEMENTS .................................................................................................................................... 27 5.4 STORM SEWER IMPROVEMENTS ............................................................................................................................ 28 5.5 UTILITIES .......................................................................................................................................................... 31 5.6 SIDE INLETS AND APPROACHES .............................................................................................................................. 31 5.7 ADEQUACY OF THE OUTLET .................................................................................................................................. 31 6.0 OPINION OF PROBABLE COST ................................................................................................................... 33 7.0 SOCIAL, ECONOMIC & ENVIRONMENTAL IMPACTS ................................................................................... 46 7.1 BENEFITED AREA AND FUNDING ............................................................................................................................ 46 7.2 PERMITS & REGULATORY REQUIREMENTS ............................................................................................................... 46 7.3 SOCIAL IMPACTS ................................................................................................................................................ 46 7.4 ECONOMIC IMPACTS ........................................................................................................................................... 46 PENNINGTON COUNTY DITCH #1 IMPROVEMENT II DETAILED SURVEY REPORT RED LAKE WATERSHED DISTRICT DITCH #14 (PROJECT NO. 171) HDR PROJECT NO. 131515 RED LAKE WATERSHED DISTRICT TABLE OF CONTENTS 7.5 ENVIRONMENTAL & LAND USE CRITERIA ................................................................................................................ 48 8.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................................................ 51 9.0 BIBLIOGRAPHY ......................................................................................................................................... 52 LIST OF FIGURES FIGURE 1. PROJECT LOCATION MAP ....................................................................................................................................... 2 FIGURE 2. HIGH FLOWS IN THE CD 1 DRAINAGE AREA ............................................................................................................... 5 FIGURE 3. FLOODING IN CD 1 DRAINAGE AREA ........................................................................................................................ 6 FIGURE 4. PONDING OCCURS AFTER RUNOFF EVENTS ............................................................................................................... 7 FIGURE 5. CD 1 OVERGROWN WITH VEGETATION .................................................................................................................... 7 FIGURE 6. PROJECT ALTERNATIVES MAP ............................................................................................................................... 10 FIGURE 7. CD 1 ALIGNMENT AND STATIONING ...................................................................................................................... 12 FIGURE 8. HEC‐HMS SCHEMATIC ....................................................................................................................................... 15 FIGURE 9. ALTERNATIVE 2 VS ALTERNATIVE 1 – 10 YEAR EVENT ................................................................................................ 18 FIGURE 10. ALTERNATIVE 3 VS ALTERNATIVE 1 – 10 YEAR EVENT .............................................................................................. 19 FIGURE 11. ALTERNATIVE 4 VS ALTERNATIVE 1 – 10 YEAR EVENT .............................................................................................. 19 FIGURE 12. ALTERNATIVE 5 VS ALTERNATIVE 1 – 10 YEAR EVENT .............................................................................................. 20 FIGURE 13. ALTERNATIVE 6 VS ALTERNATIVE 1 – 10 YEAR EVENT .............................................................................................. 20 FIGURE 14. ALTERNATIVE 7 VS ALTERNATIVE 1 – 10 YEAR EVENT .............................................................................................. 21 FIGURE 15. ALTERNATIVE 2 VS ALTERNATIVE 1 – 100 YEAR EVENT............................................................................................ 21 FIGURE 16. ALTERNATIVE 3 VS ALTERNATIVE 1 – 100 YEAR EVENT...........................................................................................