US Army Corps of Engineers BUILDING STRONG ® FARGO MOORHEAD PROJECT Pat Foley Annual Tri-Agency Meeting St. Paul, Corps of Engineers 6 October 2010

BUILDING STRONG ® Points Covered  1. How non-stationarity handled  2. Results of non-stationarity  3. How to handle climate change  4. Downstream Impacts and Project Overview

BUILDING STRONG ® 2009 Flood Fight OVERALL CITY PLAN 52 MILES OF PROTECTION 10 MILES OF SANDBAG 29 MILES OF CLAY (City) 5 MILES OF CLAY (County) 8 MILES OF HESCO 0.3 MILES OF PORTADAM

BUILDING STRONG ®

EOE Experts  David Ford, PhD Facilitator, David Ford Consultants  Michael Deering, PE, D.WRE Senior Hydraulic Engineer, Water Resource System Division, USACE Hydrologic Engineering Center  Scott Dummer, Hydrologist-in-Charge, National Weather Service North Central River Forecast Center, Chanhassen, MN  Robert Hirsch, PhD Research Hydrologist, US Geological Survey (USGS) National Research Program  Rolf Olsen, PhD Water Resources Systems Engineer, USACE Institute for Water Resources  David Raff, PhD, PE Technical Specialist, Flood Hydrology and Emergency Management Group, Technical Services Center, US Bureau of Reclamation (USBR)  Aldo (Skip) Vecchia, PhD Research Statistician, USGS North Dakota

BUILDING STRONG ® EOE Results  “experts rather quickly moved away from a discussion of climate change, per se, and focused instead on the apparent lack of stationarity in the flood flow frequency and magnitude data over the period of record (the last 110 years or so). “

BUILDING STRONG ® EOE Results  Using qualitative judgment, e.g., define the dry period as and the wet period as ; or define the dry period as and the wet period as  Use statistical tests for homogeneity to determine where to divide the POR. The expert panel did not agree on the statistical tests, but did note work by Villarini, et al  (USED PETTITT TEST)

BUILDING STRONG ® Villarini Stationarity Results

BUILDING STRONG ® Pettitt Test Statistics of Change N 108 K T+ 0 K T KTKT Year Change Point 1941 Standardized K p oa (significance Probability associated with K T- ) E- 7 p oa (significance probability associated with K T ) E- 7 Change Point: 1941

BUILDING STRONG ® Devils Lake

BUILDING STRONG ®

EOE Results  Combine the “wet” and “dry” curves, and weight the probabilities for continued wet conditions versus a reemergence of dry conditions.  (USED 0.8 WET/0.2 DRY 25 YRS AND 0.65/0.35 FOR 50 YRS)

BUILDING STRONG ®

Flow-Frequency Analysis Log-Pearson Type III

BUILDING STRONG ® Flow-Frequency Analysis Regulated

BUILDING STRONG ® Climate Change-Look Forward

BUILDING STRONG ® Climate Projections & Frequency Analysis Source: Raff, D.A, T. Pruitt, and L.D. Brekke, “A Framework for Assessing Flood Frequency Based on Climate Projection Information,” Hydrol. Earth Syst. Sci., 13, , Flow-Frequency Curves for the James River at Jamestown Blue Lines= Expanding retrospective approach Colored lines = Lookahead approach 100-yr Discharge Values in m 3 /s Expanding Retrospective Lookahead (83% higher) Percent Difference17%28%32%

BUILDING STRONG ® FLOODED AREA-ND DIVERSION

BUILDING STRONG ® DOWNSTREAM IMPACTS-GEORGETOWN ND DIVERSION, 100-YR FLOOD

BUILDING STRONG ® DOWNSTREAM IMPACTS-THOMPSON ND DIVERSION, 100-YR FLOOD

BUILDING STRONG ® DOWNSTREAM IMPACTS, ND DIVERSION, 100-YR FLOOD LOCATIONSTAGE INCREASE-FTDISCHARGE INCREASE-CFS Thompson1.3211,279 Maximum Impact Location ,294 DS Sandhill River/ Climax ,301 DS Marsh River1.6211,212 Halstad Gage0.8710,833 Hendrum0.948,970 Georgetown0.710,742

BUILDING STRONG ® FLOODED AREA-MN DIVERSION