flood risk management plan formulation, project development, & stakeholder issues
TRANSCRIPT
Flood Risk Management
Plan Formulation, Project Development, & Stakeholder Issues
Flood Risk Management Measures
Structural measures Modify flood behavior Dams and reservoirs, levees, walls, diversion
channels, bridge modifications, channel alterations, pumping, and land treatment
Nonstructural measures Modify damage susceptibility Flood warning and preparedness; Evacuation
and relocation; National Flood Insurance Program (NFIP); Flood proofing
Structural FRM Measures
Dams Reservoirs Floodwalls Levees Channels Straightening Clearing and snagging Closure structures
Bridge modifications Conveyance
modifications Pumping Channel diversions Beach Nourishment
Structural - Reservoirs
McCook, Ill.Mt. Morris Dam
Center Hill Lake, Tenn. Yatesville Lake, Ky.
Structural - Walls & Levees
Lock Haven, PAFrankfort, KY
Frankfort, KYWest Columbus
Channel Modification Projects
Harlan, KY, tunnels
Minnesota River, MN, diversion
Martins Fork, KY, diversion
River Rouge, MI, channelization
Beach Nourishment, (Before) Miami/Dade
County, FL
Beach Nourishment, (After) Miami/Dade County, FL
NATIONAL FLOOD PROOFING COMMITTEE
US Army Corps of Engineers
FloodProofing
National National Nonstructural/ Flood Nonstructural/ Flood Proofing CommitteeProofing Committee
National National Nonstructural/ Flood Nonstructural/ Flood Proofing CommitteeProofing Committeehttp://www.usace.army.mil/inet/functions/cw/cecwp/NFPC/nfpc.htmhttp://www.usace.army.mil/inet/functions/cw/cecwp/NFPC/nfpc.htm
Nonstructural FRM Measures
Elevation
Relocation
Floodwalls, Levees and Berms
Buyout/Acquisition
Dry Flood Proofing
Wet Flood Proofing
Flooding Warning/Preparedness
Elevating on Extended Foundation Walls
Elevating on Fill
Elevation on Piers, Posts, Piles, or Columns
Piers
Piles
Columns
Posts
Relocation Process
Moving the Structure Evacuate
temporary roadway
Attach structure to trailer
Transport structure to new site
Relocation Process Restoration of Old SiteRestoration of Old Site
Plan must include a new use for the evacuated floodplain
Demolish and remove foundation and pavement
Disconnect and remove all utilities
Grading and site stabilization
Evacuated floodplain area
Ring wall/levee
Ring wall/levee - closure
Ring wall/levee
Waterproof Sealant
Dry Flood Proofing: Methods
Dry Flood Proofing Method:Waterproof Sealant
Elevate Utilities
Wet Flood Proofing
Wet Flood Proofing
Louvre
Let Water In
Flood Warning/Preparedness Components
Flood Threat Recognition System
Warning Dissemination
Emergency Response
Post-Flood Recovery
Continued Plan Management
- Detailed evacuation plans and inundation mapping
- Stream gages with/without remote sensing
- Rain gages with remote sensing
Flood Warning & Emergency Evacuation Plans (FWEEP)
Nonstructural FDR Solutions
FWEEP’s are almost always cost effective and relatively inexpensive
National Flood Insurance Program 44CFR 59-78
Flood Plain Regulation (FDR)
Flood Insurance (Risk Sharing)
Flood Mitigation (FDR)
STREAM CHANNEL
FEMA Definition: 100 Year Floodplain
FLOODWAY FLOOD FRINGEFLOOD FRINGE
______________________________100 year flood _____
Base Flood
Structural and Nonstructural Measures
Structural measures keep the floods away from resources in the floodplain
Nonstructural measures keep the resources away from floods in the floodplain
Basic Formulation Strategy
The basic formulation strategy is to formulate to meet each of your planning objectives without violating any constraints.
Every iteration of the formulation step must employ this basic strategy.
How - Formulation Strategies
All possible combinations
Measures strategy
Convergent thinking
Divergent thinking
Formulation Strategies
Outputs Maximum damage
reduction
Life cycle costs
Sponsor financial capability
Locally Preferred (LPP)
Change location Flood Resources
Nonstructural (statutory requirement)
Change timing Flood Resources
Change magnitude Flood Resources
New Uses of the Evacuated Flood Plain Ecosystem Restoration Recreation Spillover Benefits
Water Quality Improvement E.O. 11988 NFIP Regulations Mitigation of Adverse Effects of Structural
Projects
Nonstructural Opportunities
How do we help this situation?
High groundbehind red line
Town limits
What measures would help?
High groundbehind red line
Levee/Wall?
Detention pond?
Town limits
Channel Modification?Non-Structural Measures?
Evaluation of Existing
Damage Reach
Discharge
Dis
char
ge
Discharge
Probability
Sta
ge
StageD
amag
e
Future Without Conditions
Damage Reach
Discharge
Dis
cha
rge
Discharge
Probability
Sta
ge
Stage
Fill placement to elevate new development
New Development
Attrition of damaged property
Urbanization affects funoff
Channel Modification
Damage Reach
Discharge
Discharge
Dis
char
ge
Probability
Sta
ge
Stage
Dam
age
May induce higher flow rates downstream if storage eliminated
Reservoir / Detention Storage
Damage Reach
Discharge
Discharge
Dis
char
ge
Probability
Sta
ge
Stage
Dam
age
Non-Structural Measures
Damage Reach
Discharge
Discharge
Dis
char
ge
Probability
Sta
ge
Stage
Dam
age
Raise
Floodproof
Levee
Damage Reach
Discharge
Discharge
Dis
char
ge
Probability
Sta
ge
Stage
Dam
age
HEC-FDA S-$ curve
HEC-FDA truncated in EAD
FDA Model Evaluates Measures
Mathematical models are used to evaluate the impacts of alternatives for flood damage reduction
The Corps’ Flood Damage Assessment (FDA) model of expected annual damage estimation is the preferred method of modeling the effects of formulated plans
Developed and Maintained at HEC – Specific training is available on the FDA model
0
200000
400000
600000
800000
1000000
1200000
Stage
Dama
ge
020000400006000080000
100000120000140000160000180000
Stage
Disc
harg
e
0
20
40
60
80
100
120
Discharge
Freq
uenc
yFormulation With FDA Model
Walls, leveesFloodproofing
ChannelsClearing & snagging
DamsDetention reservoirs
DISCHARGE FEET FREQUENCY DAMAGES ANNUAL DAMAGES -------- ----- --------------- ------------------ ------------------ 1000's NGVD % % INTERVAL AT STAGE AVERAGE INTERVAL SUMMATION
0 910 99.999999 na $0 na NA3000 911 99.99999 0.000 $0 $0 $0 $06000 912 99.9999 0.000 $0 $0 $0 $08500 913 99.999 0.001 $0 $0 $0 $0
12000 914 99.99 0.009 $0 $0 $0 $015500 915 92 7.990 $0 $0 $0 $018000 916 44 48.000 $0 $0 $0 $022000 917 26 18.000 $25,435 $12,717 $2,289 $2,28926000 918 20 6.000 $44,462 $34,948 $2,097 $4,38629500 919 14 6.000 $60,830 $52,646 $3,159 $7,54534000 920 10 4.000 $69,770 $65,300 $2,612 $10,15738000 921 7 3.000 $86,980 $78,375 $2,351 $12,50842500 922 5 2.000 $118,074 $102,527 $2,051 $14,55948000 923 4.7 0.300 $144,044 $131,059 $393 $14,95252500 924 3.7 1.000 $152,355 $148,200 $1,482 $16,43458000 925 2 1.700 $160,326 $156,340 $2,658 $19,09263000 926 1.6 0.400 $168,262 $164,294 $657 $19,74970500 927 1.4 0.200 $176,062 $172,162 $344 $20,09379500 928 1.2 0.200 $183,964 $180,013 $360 $20,45390000 929 0.9 0.300 $191,832 $187,898 $564 $21,017
102000 930 0.65 0.250 $199,359 $195,596 $489 $21,506112000 931 0.5 0.150 $207,432 $203,396 $305 $21,811128000 932 0.38 0.120 $215,266 $211,349 $254 $22,064142000 933 0.3 0.080 $225,621 $220,443 $176 $22,241157000 934 0.22 0.080 $227,877 $226,749 $181 $22,422
EADCalculation for with projectcondition
Where do we begin in formulation?
High groundbehind red line
Levee/Wall?
Detention pond?
Town limits
Channel Modification?Non-Structural Measures?
First or Last?
High groundbehind red line
Levee
Detention pond
Dependencies
Flood damage reduction plans often comprise several measures
Some measures may require implementation of other measures in order to function properly:
Interior drainage measures (pump stations and/or ponding areas) with levees/floodwalls
Warning system, operations manual, or FWEEP when plans have closure structures requiring human intervention (put the sand bag in the slot, flip the switch on the gate motor power control, etc.)
Combinability
Flood damage reduction plans often comprise several increments
More often flood damage reduction plans have measures that can be combined in many ways, shapes, and sizes to achieve NED
-$15M$85M$100MChannel
$20M$80M$60MLevees/Walls
-$20M$20M$40MPond
$10M$40M$30M Non-Structural
Measure NED Cost NED Benefit Net NED Benefit
Initial Formulation (we have only just begun)
And we look at it all again - Reformulation
First or last positioning of measures
Dependencies
Combinability
Incremental Analysis
Increment Defined
An increment is any part of a plan that can be eliminated without jeopardizing the proper function of the remaining parts of the plan.
Thus, different levels of project performance are not increments.
WRDA 1986 Definition of Separable Element. “For purposes of this Act, the term "separable element" means a portion of a project-- (1) which is physically separable from other portions of the project; and (2) which-- (A) achieves hydrologic effects, or (B) produces physical or economic benefits, which are separately identifiable from those produced by other portions of the project.”
Another Example - What’s An Increment?
High groundbehind red line
Reach 1
Reach 2
Reach 3
Levee alignment
Levee tie-back options
Town limits
Separable Increments of a Flood Damage Reduction Plan
Plan Increment NED CostsNED
BenefitsNet NED Benefits
Levee A (1) $21M $20M -$1M
Levee B (1&2) $40M $70M $30M
Levee C (1,2 &3) $60M $80M $20M
Separable Increments – Did we miss an opportunity the first time?
Plan Increment NED CostsNED
BenefitsNet NED Benefits
Levee D (2) $21M $50M $29M
Levee E (3) $20M $10M -$10M
Levee F (2 &3) $39M $60M $21M
Identifying the NED Plan
Without-project damages With project damages Benefits are damages reduced Net benefits are benefits less project costs (total life cycle
costs, including environmental mitigation) Compare across project scales and between alternatives
to determine plan that yields greatest NED benefits Decision-makers always have the final say
Environmental Consequences
Flooding is natural; flood damage reduction is not Flood damage reduction measures can have
environmental consequences Some are intended, some are not Some are anticipated, some are not Some are beneficial, some are adverse Unanticipated, unintended consequences may be
the worst type
Flood Plain Management Issues
Induced flooding is not the NED issue
Induced damages are the issue
Avoiding or mitigating for induced damages are part of project costs and must be considered in plan formulation
Induced flooding is an NFIP/EO 11988 issue that must be disclosed in the documentation
Where does the water go?
Flood Protection Levee Lock Haven, PA
Do you think this property could be affected?
FEMA and NED Formulation Issues
National Flood Insurance Program participation assumed
FEMA coordination essential and a matter of policy
FEMA buyout land restrictions on Corps measures
Locally desired protection (especially 100-year)
Sponsors’ Old RoleSponsors’ Old Role Sponsors’ Old RoleSponsors’ Old Role Prior to 1986:
Not as politically active
Uninvolved in project development
No cost sharing other than LERRD’s
Sponsors’ Changing RolesSponsors’ Changing Roles Sponsors’ Changing RolesSponsors’ Changing Roles Today’s Sponsors are:
Very politically active In many cases technically capable of
accomplishing work without COE support
Actively involved in project development
Demanding faster, better, cheaper Want special application of policies for their
projects.
Sponsors Political ActivitiesSponsors Political ActivitiesSponsors Political ActivitiesSponsors Political Activities
Actively building state and local coalitions
Campaigning for tight state revenues
Working closely with Congressional Delegations
Actively participating in national associations
Engaging ASA(CW)
Actively building state and local coalitions
Campaigning for tight state revenues
Working closely with Congressional Delegations
Actively participating in national associations
Engaging ASA(CW)
Greater Involvement in Project Greater Involvement in Project DevelopmentDevelopmentGreater Involvement in Project Greater Involvement in Project DevelopmentDevelopment
- Integral member of study team - Performing more in-kind services - Meeting often with Corps team - In on major study changes - Will call and visit HQ quickly
Greater Involvement in Project Greater Involvement in Project DevelopmentDevelopmentGreater Involvement in Project Greater Involvement in Project DevelopmentDevelopment Congress provided sponsors authorities to conduct
planning, design and construction of project.
Section 203 WRDA 86 - study deep draft navigation Section 204 WRDA 86 - design and construct deep
draft navigation Section 303 WRDA 90 - construct small navigation
projects Section 206 WRDA 92 - construct shoreline
protection projects Section 211 WRDA 96 - construct flood control
project Section 2003 WRDA 07 – credits for materials and
services provided for design and/or construction
Demanding Faster, Better, CheaperDemanding Faster, Better, CheaperDemanding Faster, Better, CheaperDemanding Faster, Better, Cheaper
Section 203 WRDA 96
– If feasibility study cost increases greatly after the FCSA has been signed, the sponsor’s incremental share can be delayed until after project construction or 5 years after the Chief of Engineers’ report is issued.
Reconnaissance Studies
Equal TreatmentEqual TreatmentEqual TreatmentEqual Treatment
- Regional consistent analysis
- Equal application of policies
- In-kind credit Crediting for construction related activities now allowed under
Section 2003 of WRDA 2007!!
Take Away Points
Plan formulation is the art of creating plans to address the objectives and constraints related to flood damage reduction problems and opportunities
In developing plan formulation strategies, you need to understand the basic policies affecting plans for flood damage reduction improvements.
Breakpoints in costs are especially important to formulation and associated costs need to be included in the analysis
While a study may recommend a locally preferred plan, the NED Plan establishes the limit on the Federal investment.