Appendix A-1a Hydrology Fargo-Moorhead Metropolitan Area Flood Risk Management Supplemental Draft Feasibility Report and Environmental Impact Statement April 2011 Prepared by: U.S. Army Corps of Engineers St. Paul District 180 Fifth Street East, Suite 700 St. Paul, Minnesota 55101-1678 Table of Contents 1.0 OBJECTIVE AND STUDY LIMITS.....................................................................................................7 2.0 DESCRIPTION OF WATERSHED ......................................................................................................7 2.1 RED RIVER OF THE NORTH .............................................................................................................7 2.2 BOIS DE SIOUX RIVER ....................................................................................................................11 2.3 OTTER TAIL RIVER .........................................................................................................................12 2.4 SHEYENNE RIVER ...........................................................................................................................12 2.5 STREAM GAGES ..............................................................................................................................14 2.6 NOMENCLATURE............................................................................................................................22 3. REGULATORY EFFECTS...................................................................................................................23 3.1 RESEVOIR BACKGROUND INFORMATION................................................................................23 3.2 1997 SPRING FLOOD........................................................................................................................33 3.3 2001 SPRING/ SUMMER FLOOD ....................................................................................................34 3.4 2006 SPRING FLOOD........................................................................................................................36 3.5 2009 SPRING FLOOD........................................................................................................................37 3.6 REGULATED VS. UNREGULATED CONDITION .........................................................................39 4. PERIOD OF RECORD DISCHARGE-FREQUENCY ANALYSIS .................................................41 4.1 RED RIVER AT FARGO, ND ............................................................................................................41 4.2 RED RIVER AT WAHPETON, ND ...................................................................................................52 4.3 RED RIVER AT HICKSON ...............................................................................................................57 4.4 WILD RICE RIVER, ND ....................................................................................................................59 4.5 RED RIVER AT HALSTAD ..............................................................................................................63 4.6 RED RIVER AT GRAND FORKS .....................................................................................................63 4.7 RED RIVER REACH BETWEEN WAHPETON AND GRAND FORKS .........................................63 5. HEC-RAS MODEL CALIBRATION & VERIFICATION.................................................................66 6. BALANCED HYDROGRPAHS ............................................................................................................66 6.1 GAGED LOCATIONS .......................................................................................................................67 6.2 UNGAGED LOCATIONS .................................................................................................................68 6.3 HYDROGRAPH DEVELOPMENT ...................................................................................................68 7. OVERBANK STORAGE........................................................................................................................68 8. SYNTHETIC EVENT DETERMINATION .........................................................................................69 9. EXPERT OPINION ELICITATION ....................................................................................................69 10. REFERENCES ......................................................................................................................................73 Supplemental Draft Fargo-Moorhead Metro Feasibility Report A-1a-2 April 2011 Hydrology Table of Figures FIGURE 1- RED RIVER OF THE NORTH BASIN AND MAINSTEM STREAM GAGES ..............................................75 FIGURE 2-RED RIVER OF THE NORTH: SHEYENNE & UPPER RED BASIN ABOVE FARGO.................................76 FIGURE 3- MODEL SCHEMATIC ......................................................................................................................77 FIGURE 4- MODEL SCHEMATIC ......................................................................................................................78 FIGURE 5- DRAINAGE AREA SCHEMATIC FOR HEC-5 .....................................................................................79 FIGURE 6- BOIS DE SIOUX RIVER BREAKOUT FLOW SCHEMATIC ...................................................................80 FIGURE 7- MAJOR DRAINAGE AREA SUBDIVIDED AT PERTINENT LOCATIONS FOR THE SHEYENNE RIVER ....81 FIGURE 8- USGS GAGE LOCATIONS ...............................................................................................................82 FIGURE 9- PEAK STREAMFLOW GAGE STATIONS AND PERIOD OF RECORD ....................................................83 FIGURE 10- LAKE TRAVERSE PROJECT MAP ..................................................................................................84 FIGURE 11- WHITE ROCK DAM, LAKE TRAVERSE PROJECT (LOOKING DOWNSTREAM) .................................85 FIGURE 12- ORWELL RESERVOIR PROJECT MAP ............................................................................................86 FIGURE 13- ORWELL DAM PHOTOGRAPHS......................................................................................................87 FIGURE 14- PROJECT MAP FOR BALDHILL DAM .............................................................................................88 FIGURE 15- BALDHILL DAM PHOTOGRAPH ....................................................................................................89 FIGURE 16. RED LAKE PROJECT MAP .............................................................................................................90 FIGURE 17. RED LAKE DAM PHOTOGRAPH .....................................................................................................91 FIGURE 18- HYDROGRAPHS FOR SPRING 1997 EVENT FOR LAKE TRAVERSE .................................................92 FIGURE 19- HYDROGRAPHS FOR SPRING 1997 EVENT ORWELL DAM ............................................................93 FIGURE 20- HYDROGRAPHS FOR SPRING 1997 EVENT FOR BALDHILL DAM ...................................................94 FIGURE 21. SPRING 1997 EVENT AT RED LAKE DAM .....................................................................................95 FIGURE 22- HYDROGRAPH FOR SPRING/SUMMER 2001 EVENT LAKE TRAVERSE ...........................................96 FIGURE 23- HYDROGRAPH FOR SPRING/SUMMER 2001 EVENT ORWELL DAM ...............................................97 FIGURE 24- HYDROGRAPH FOR SPRING/ SUMMER 2001 EVENT FOR BALDHILL DAM.....................................98 FIGURE 25. 2001 SPRING EVENT AT RED LAKE DAM .....................................................................................99 FIGURE 26. HYDROGRAPH FOR SPRING 2006 EVENT LAKE TRAVERSE ........................................................100 FIGURE 27. HYDROGRAPH FOR SPRING 2006 EVENT ORWELL DAM.............................................................101 FIGURE 28. HYDROGRAPH FOR SPRING 2006 EVENT BALDHILL DAM ..........................................................102 FIGURE 29- HYDROGRAPH FOR SPRING FLOOD EVENT 2009 LAKE TRAVERSE ............................................103 FIGURE 30- HYDROGRAPH FOR SPRING FLOOD EVENT 2009 ORWELL DAM ................................................104 FIGURE 31- HYDROGRAPH FOR SPRING FLOOD EVENT 2009 BALDHILL DAM ..............................................105 FIGURE 32. 2009 EVENT AT RED LAKE DAM................................................................................................106 FIGURE 33. WET FLOW FREQUENCY CURVE- COMPARISON WET REGULATED VS WET UNREGULATED ...107 FIGURE 34. DRY FLOW FREQUENCY CURVE- COMPARISON DRY REGULATED VS DRY UNREGULATED....108 FIGURE 35- DISCHARGE-FREQUENCY CURVE, RED RIVER AT FARGO-, ANNUAL MEAN DAILY PEAKS .......109 FIGURE 36- REGRESSION RELATIONSHIP BETWEEN MEAN DAILY AND INSTANTANEOUS PEAKS FOR THE RED RIVER AT FARGO ................................................................................................................................110 FIGURE 37- FLOW-FREQUENCY CURVE: ANNUAL INSTANTANEOUS PEAKS FOR THE RED RIVER OF THE NORTH AT FARGO ...............................................................................................................................111 FIGURE 38-REGRESSION RELATIONSHIP RELATING REGULATED AND SIMULATED NATURAL MEAN DAILY FLOWS FOR THE RED RIVER OF THE NORTH AT FARGO. ......................................................................112