Fargo-Moorhead
Metropolitan Feasibility
Study
Presentation
for
City Engineers
Association of
Minnesota
January 28, 2010
28 January 2010 2
Partners
Corps of Engineers
City of Fargo
City of Moorhead
Metropolitan Flood Management Committee
28 January 2010 3
Why We Are Here
Fargo-Moorhead area
has significant flood
risk
Provide an overview
of the process and
outcomes of the
Fargo-Moorhead
Feasibility Study.
Fargo-Moorhead Flood 2009
28 January 2010 4
Funding and Costs
Study costs are shared 50% federal, 50% non-federal
Congress provides federal funds to the Corps
Non-federal funding is provided by:
City of Fargo, ND
City of Moorhead, MN
Buffalo-Red River Watershed District, MN
Cass County, ND
Estimated study cost: $8,000,000
Construction costs are shared 65% fed, 35% non-fed
28 January 2010 5
Planning Process
1. Specify problems and opportunities.
2. Inventory and forecast conditions.
3. Formulate alternative plans.
4. Evaluate effects of alternative plans.
5. Compare alternative plans.
6. Select recommended plan.
28 January 2010 6
Study Goals
Develop a system to reduce regional flood risk
Determine the Federal role in implementation
Document findings in a Feasibility Report
Recommend a project to Congress
28 January 2010 7
Study Area
Fargo-Moorhead
metropolitan & surrounding
area
North: Harwood, ND &
Kragnes, MN
South: Oxbow, ND
East: Dilworth, MN
West: West Fargo, ND
28 January 2010 8
Risk
The 2009 flood was
approximately a 125 year flood
event.
Successful flood fights lead to a
false sense of security.
It would be very difficult to fight
floods larger than the 2009 flood.
Failure of emergency levees
would be catastrophic.
Building of 2nd St. Levee for 2009 Fargo-Moorhead Flood
28 January 2010 9Potential Depths of Inundation
28 January 2010 10Potential Depths of Inundation
28 January 2010 11
Loss of Life
Event
Anticipated
Event
98%
Evacuation
Unanticipated
Event
0%
Evacuation
1% Chance
(100 yr)4 200
0.2% Chance
(500yr)12 594
*Assume Total Metro Population 202,684
28 January 2010 12
Hydrologic record shows two periods: wet and dry
Annual Peak StagesU.S.G.S Station - 05054000
0
5
10
15
20
25
30
35
40
45
50
1882 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
DATE
ST
AG
E, fe
et
FEMA 500-yr Event FEMA 100-yr Event FEMA 50-yr Event FEMA 10-yr Event
FEMA 100-yr Event
Wetter Climate?
28 January 2010 13
Wetter Climate?
Panel of experts met to discuss hydrology Confirmed increasing trend in flood flow and frequency
Cause of increasing trend is not known
Red River has wet & dry cycles
Currently in a wet cycle, but will eventually switch to dry cycle
Recommendations Use non-standard hydrologic method to estimate future flows
Assume that continued wet conditions are more likely than dry
Actions taken Corps developed modified flow/frequency curves
Will use modified curves for sensitivity analysis of selected plan
28 January 2010 14
Alternatives
No Action: Continue Emergency Measures
Nonstructural measures Buyouts, Relocations, and Elevate
Increase conveyance Diversion Channels
Flood barriers Levees/Floodwalls
Flood storage Large/Small
28 January 2010 15
Initial Screening Criteria
Effectiveness: Ability to provide acceptable level of flood risk management
Environmental Effects: Effects on natural and cultural resources
Social Effects: Effects on socio-economic resources
Acceptability: Controversy and potential effects on community
Implementability: Technical, social, legal or institutional issues
Cost: The first cost of the project and operations and maintenance.
Risk: The uncertainties surrounding the project
Separable Mitigation: Is separable mitigation required and what is the cost
Cost Effectiveness: Comparison of benefits and costs
28 January 2010 16
Preliminary Screening ResultsScreened Alternatives Ranked by Net Benefits
Alternative First Cost *
Avg Annual
Net Benefits *
Residual
Damages * B/C Ratio
MN Short Diversion 25K 962 11.0 14.3 1.22
MN Short Diversion 35K 1,092 9.4 9.3 1.17
Levee 1% chance (100-year) 902 7.7 20.9 1.17
MN Long Diversion 25K 1,055 5.6 15.0 1.10
MN Short Diversion 45K 1,264 2.5 7.4 1.04
MN Long Diversion 35K 1,260 0.3 9.8 1.00
ND East Diversion 35K 1,337 -3.1 9.2 0.95
ND West Diversion 35K 1,363 -4.4 9.2 0.94
Levee 2% chance (50-year) 840 -5.3 37.1 0.88
ND West Diversion 45K 1,439 -6.7 7.6 0.91
MN Long Diversion 45K 1,459 -8.3 8.2 0.89
* In millions of dollars
Note: Expected average annual damages without a project are $73.7 million.
28 January 2010 17
Final Screening Alternatives
Diversion Channels with Tie Back Levees Minnesota
North Dakota
28 January 2010 18
Detailed Analysis
Working on Detailed Analysis
MN Diversions with Tie Back Levee
4 separate plans (4 capacities: 20,000,
25,000, 30,000, and 35,000cfs)
ND Diversion with Tie Back Levee
1 plan (2 capacities: 30,000 and
35,000cfs)
28 January 2010 19
Preliminary ResultsEffects of Diversions
STAGE at the FARGO GAGE
2% Chance 1% Chance 0.2% Chance
(50-year) (100-year) (500-year)
Existing Condition 37.8 39.5 43.9
25k Diversion 29.1 30.4 39.2
35k Diversion 28.8 29.2 35.9
45k Diversion 27.1 27.2 30.4
Stage Impacts
27 Fargo Elm Street closed
30 Fargo 2nd Street Dike installed
31 Moorhead 1st Ave. North closed
32 First homes in Moorhead threatened
35 First homes in Fargo threatened
40.8 2009 Flood Record Stage
28 January 2010 20
Preliminary ResultsEffects of Diversions
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
2% Chance (50-year) 1% Chance (100-year) 0.2% Chance (500-year)
Sta
ge
in
Fe
et
Existing Condition 25k Diversion 35k Diversion 45k Diversion
28 January 2010 21
Recreation
Eligible Recreational Facilities Trails – Hiking, Snowmobile, Cross Country Skiing, etc.
Footbridges
Fishing Facilities
Picnic Shelters, Overlooks, Restrooms
Camping facilities, picnic tables, grills, etc.
Multiple Use Courts
Interpretative Signs and Information
28 January 2010 22
Path Forward
Uncertainties: Natural Resource impacts (fish passage – greater for ND diversion
alignments)
Additional project benefits
Impacts to upstream/downstream landowners
Upcoming Tasks Develop additional benefit information
Develop costs for any negative impacts
Narrow down capacity alternatives
Choose 1 alignment
28 January 2010 23
Local Decisions
What level of risk is tolerable?
36 feet for a 500-year event.
What locally preferred options need to be retained?
MN 35K, ND 30 & 35K
Identify sponsors for construction and ongoing O&M
Define non-federal cost sharing arrangements
Non-federal share of the NED plan will be 35-50% of costs
All costs in excess of the NED plan are 100% non-federal
Develop local consensus
28 January 2010 24
F-M METRO STUDY TIMELINE
Feb 2010: Identify unofficial tentatively selected plan
Feb 2010: Public Meeting
Mar 2010: Independent External Peer Review
Apr 2010: Corps headquarters approval to release draft
May 2010: Formal Public Review of Feasibility
Report
Sep 2010: Finalize feasibility report
Dec 2010: Transmit recommendation to Congress
Jan 2011: Begin Plans and Specifications
Apr 2012: Begin Construction
28 January 2010 25
Red River Basin Wide Feasibility
28 January 2010 26
Red River Basin Wide Feasibility
Sponsors MN Red River Watershed
Management Board
ND Red River Joint Water Resource District
Cost Share 50/50
All local share as WIK
Acceptable WIK Coordinated in advance
Provides information beneficial to the Basin
Project Overview
28 January 2010 27
Red River Basin Wide Feasibility
Phase I – LiDAR Collection – complete
Processing – ongoing
Development of web viewer
Used in 2009 flood
Phase II - Modeling HEC-RAS for entire Red River
HEC-HMS for watersheds
Mike-11
Phase III - Decision Support System Development of tools for local use
Modification of RRBDIN (IWI)
Needs Local Direction
Final Report Basin Goals and Objectives (RRBC)
Existing and future conditions
Information on tools developed in study
Project Overview
28 January 2010 28
Red River Basin Wide Feasibility
H&H Modeling
Mike 11 - RRBC
HEC-RAS – Corps
Extending Cross sections
Working with NWS on forecasting
HEC-HMS - Corps
Decision Support System
GIS analysis of LiDAR
Identify storage opportunities
Identify restoration opportunities
Public Outreach and Collaboration (RRBC/IWI)
Flood Forecast Tool
Drought Forecast Tool
Long Term Maintenance, Support, and Upgrades
Future/Ongoing Work
28 January 2010 29
Red River Basin Wide Feasibility
Develop Tools and Information Addressing the Needs of the individual Stakeholders
Cities
Counties
States
Watershed Districts
No Federal Implementation
Sponsors Role Continue to identify needs in the basin
Provide financial and political support
Continue participation in the study
Encourage Public participation in the future.
Direct future planning efforts
Purpose of Corps Involvement
28 January 2010 30
Questions?
Information on back of handout
Please sign our sheet to get future mailings.
Website: http://www.internationalwaterinstitute.org/feasibility
Email:
Craig Evans – [email protected]
Aaron Snyder – [email protected]
Mail:
USACE, St. Paul District
190 5th St. E.
Suite 401
St. Paul, MN 55104
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