ASFPM Partnerships for Statewide Mitigation Actions Alicia Williams GIS and HMP Section Manager, Amec Foster Wheeler June 2016
Summary The Concept Leveraging Existing Data and Partnerships to reduce risk The Opportunity Utilize FEMA Data Regulatory (DFIRM) RiskMAP Products Utilize MODOT Transportation Data Utilize MSDIS Statewide Structure Data Utilize Census Block Data The Potential Mitigation Ideas Using Out of the Box FEMA Products coupled with readily available data
What is Risk MAP? Mitigation is the effort to reduce loss of life and property by lessening the impact of disasters. In order for mitigation to be effective we need to take action now before the next disaster to reduce human and financial consequences later. 3
What is a Mitigation Project? A mitigation project is a specific undertaking by a community to reduce or eliminate long-term risk to people and property from hazards. Question? What s the best kind of Mitigation Project? Answer: The one you can/will do 4
Regulatory Products Risk MAP regulatory products present the flood hazard data and consist of the Flood Insurance Rate Map (FIRM), Flood Insurance Study (FIS) report, and FIRM database. These regulatory products must be adopted by the community and incorporated into either their floodplain management ordinance, in order to participate in the National Flood Insurance Program (NFIP), or their local building code in order to comply with the flood hazard provisions contained therein. The regulatory products are further defined below: Flood Insurance Rate Map (FIRM) FIRMs are maps developed by FEMA to identify flood hazards. The FIRM is the official map of a community that shows the special flood hazard areas (SFHA) and the risk premium zones applicable to the community. The FIRM is published as the legal document for flood insurance rates. Flood Insurance Study (FIS) Report The FIS report accompanies the FIRM and provides the associated flood information and technical methods that were used to develop the FIRM. Flood information includes, at a minimum, the 1-percent-annual-chance flood elevations, velocity data, floodway widths, bridge and dam locations, and plotted flood profiles of the flood elevations along the stream reaches that were studied. FIRM Database - The FIRM Database is a Geographic Information Systems (GIS) version of the FIRM and most of the quantitative data in the FIS. The GIS data is designed to provide the community with the ability to determine the flood zone, base flood elevation and the floodway status for a particular location. The database also contains NFIP community information, map panel information, cross section and hydraulic structure information, and base map information such as road, stream, and public land survey data.
RiskMAP Products Flood Risk Map (FRM) The FRM presents a high-level, flood risk overview of the project area. The content and format of individual FRMs may vary among project areas to best represent the local conditions. Typical maps include the potential flood losses associated with the one-percent annual chance flood event for each census block, key watershed features that affect local flood risk, and information about potential or successful past mitigation projects to reduce flood risk. This graphical presentation of flood risk data enables communities to visually identify flood risk hot spots and to facilitate coordination with neighboring upstream and downstream communities. Flood Risk Report (FRR) The Flood Risk Report provides communities with a comprehensive understanding of flood risk exposure within their jurisdiction, watershed or other geographic project area. This report provides a narrative of the flood risk assessment methodology and results, as well as risk assessment information that can be incorporated into hazard mitigation plans. The FRR, used in combination with the Flood Risk Map, is a good tool for communities to use for raising local flood risk awareness. Flood Risk Database (FRD) - The FRD is the GIS version of the FRM and most of the quantitative data in the FRR. The FRD provides a wealth of data that may be used to analyze, communicate and visualize flood risk on an ad-hoc basis for a variety of uses. Communities are encouraged to use this database to support mitigation efforts and raise awareness. Data in the FRD represents a snapshot-in-time. Data is not updated regularly once the final FRD is posted to the Map Service Center. The primary datasets contained within the FRD include:
Flood Risk Database (FRD) Flood Depth Grid presents the depth of flooding at any given location in the floodplain. For new Risk MAP projects, depth grids may include the 10-, 4-, 2-, 1-, and 0.2-percent-annualchance flood events for riverine flooding and can be produced for areas affected by levee and dam flooding. Percent-Annual-Chance Probability Grid presents the probability of flooding in any given year (true risk of flooding as a statistical probability). 30-Year-Chance Probability Grid presents the probability of a location being flooded during the life of a 30-year mortgage. Water Surface Elevation Change Grid displays areas where the Risk MAP project resulted in changes to the calculated water surface elevations. Velocity Grid provides floodwater velocity information at any given location in the floodplain showing that hazards and risk vary across the floodplain. This information can be used to identify where building foundations in new or retrofit construction are at risk from higher velocity forces.
Where do RiskMAP Products in Missouri?
Mitigation Actions can be broadly categorized as..
Let s look at the available data SFHA Layer from Map Service Center http://msc.fema.gov/portal
Structures File from MSDIS (Missouri Spatial Data Information) hosted by the University of Missouri http://www.msdis.missouri.edu/data/datalist.html#facstruc
Transportation Files from MODOT also on MSDIS (Missouri Spatial Data Information) hosted by the University of Missouri http://www.msdis.missouri.edu/data/datalist.html#facstruc
Preliminary FEMA SFHA -Example for Howard County, Missouri Preliminary Special Flood Hazard Area for Howard County Zone A = green Zone AE = red Floodway = orange hatch
MSDIS Structure Products for Howard County MSDIS Structures for Howard County as points on all structures in the county 9834 points or rooflines in the county Coded for type of Structure
Understanding the available data is the key All structures in the county 9834 points or rooflines in the county 3250 of which are residential 153 are Mobile Homes 55 are Multi-family dwelling 3036 are Single Family dwellings Coded for type of Structure
Simple Queries of the Data tell us a lot Intersect the structure points with the SFHA, a buffer can be applied easily Results of a Query of the data for residential structures within 250 feet of the Special Flood Hazard Area (SFHA) All structures in the county 9834 points or rooflines in the county Coded for type of Structure 3250 of which are residential 153 are Mobile Homes 55 are Multi-family dwelling 3036 are Single Family dwellings As FPAs, we re always concerned about all the citizens of a county but now efforts can be focused and limited resources used for the worst first.
Additional Queries coupled with symbology changes This Query shows residential structures within 250 feet of the SFHA symbolized with stars by differentiated by Zone type Zone A = red stars for structures near detailed studied areas 51 structures Zone AE = green stars for structures near Approximate areas 215 structures Floodway = purple stars for structures near the Floodway 44 structures I ve narrowed my efforts from 9000+ to 310 structures.
Determine the Depth of Water for all events for structures in the SFHA For structures in the SFHA, the Depth Grid is a great tool to describe risk to the homeowner Map Tips work great This structure would have an estimated 5.7 feet of Using the Extract Multi Values to Points tool in GIS, the values for depth for all the events can be added to a point making it easy to query.
Mitigation Action Identification Using RiskMAP Products Mitigation Categories Prevention Property Protection Public Education and Awareness Natural Resources Protection Emergency Services Structural Projects
Local Planning and Regulations Preventative Measures F1- Incorporate Flood Mitigation into Local Planning For the State Hazard Mitigation Plan, all counties with DFIRMs at least Preliminary will have depth grids created using the DFIRM data for the HAZUS Analysis This analysis will be available for local planning efforts to roll down to utilize.
Local Planning and Regulations Preventative Measures F2- Form Partnerships to Support Floodplain Management NRCS- Dam As-Builts USACE Leverage Studies and Levees MODOT Bridge Plans
Local Planning and Regulations Preventative Measures F3 Limit or Restrict Development in Floodplain Areas The Percent Annual Chance Grid can be used to determine which areas should be restricted for development. In this example any area in dark red has a 50% or greater chance of flooding once a year.
Local Planning and Regulations Preventative Measures F4- Adopt and Enforce Building Codes and Development Standards Low High Density Areas Areas Target the high density areas with greater than 1 foot of water for Building Code adoption actions using the depth grids
Local Planning and Regulations Preventative Measures F5 Improve Stormwater Management Planning High Density Areas Target the high density areas for Stormwater Management Planning actions with flooding depths greater than 1 foot as indicated by the flood depth grids.
Local Planning and Regulations Preventative Measures F6 Adopt Policies to Reduce Stormwater Runoff Target Homeowners in the floodplain in densely developed areas for outreach materials encouraging the use of permeable driveways and patios surfaces If further refinement is needed, the flood depth grid can be used to select for homes with more than 1 foot of depth.
Local Planning and Regulations Preventative Measures F7 Improve Flood Risk Assessment
Local Planning and Regulations Preventative Measures F8 Join or Improve Compliance with NFIP SFHAs in Missouri NFIP Participation as of May 31, 2016
Local Planning and Regulations Preventative Measures F9 Manage the Floodplain Beyond Minimum Requirements Sinkholes are a major issue in the southern half of Missouri. Managing sinkhole areas in addition to or conjunction with the SFHA is beyond the minimum requirements but an especially important mitigation action for this area.
Local Planning and Regulations Preventative Measures F10 Participate in the CRS Current Participants in CRS in Missouri If we want to focus our efforts, we can define the areas with dense populations with depth of water greater than 1 foot.
Local Planning and Regulations Preventative Measures F11 Establish Local Funding Mechanisms for Flood Mitigation Set aside general fund dollars equivalent to 5% of the assessed value of the homes located within the SFHA. An alternative would be for the homeowners who live within the SFHA who do not have LOMAs could be levied a tax to fund mitigation actions. I m not saying all actions would be popular
Structure and Infrastructure Projects F12 Removing Existing Structures from Flood Hazard Areas - Buyouts For the 44 structures in the FW in our example, perhaps buyout efforts are focused there Before-floodprone structures After- open green space
Structure and Infrastructure Projects F13 Improve Stormwater Drainage System Capacity Using floodplains and depth grids to determine undersized bridges and culverts.
Structure and Infrastructure Projects F14 Conduct Regular Maintenance for Drainage Systems and Flood Control Structures Utilizing partnerships with the USACE and local Levee owners, maintenance records for these systems can be assessed to ensure actions are being implemented. RiskMAP products can be used to assist in Freeboard analysis
Structure and Infrastructure Projects F15 Elevate or Retrofit Structures and Utilities All structures in the county 9834 points or rooflines in the county Coded for type of Structure 3250 of which are residential 153 are Mobile Homes 55 are Multi-family dwelling 3036 are Single Family dwellings
Structure and Infrastructure Projects F16 Floodproof Residential and Non- Residential Structures Target the most vulnerable homes for Floodproofing Outreach
Structure and Infrastructure Projects F17- Protect Infrastructure Using the depth grids and transportations lines, bridges that show road overtopping can be identified for high priority replacement.
Emergency Services F18 Protect Critical Facilities Flood Depth Grids Raster (grid) of water depth Depth is calculated as the difference (in feet) between the water surface elevation and the ground Produced for 10%, 4%, 2%, 1%, and 0.2% annual chance events
Emergency Services F19 Construct Flood Control Measures Flood depth grids would be excellent for assessing water treatment facilities which have the potential to flood.
Natural Systems Protection F20 Protect and Restore Natural Flood Mitigation Features Percent Annual Chance of Flooding Grid can be used to designate areas natural wetlands and retaining thick vegetative cover on public lands flanking rivers In this example the dark red is 50% or greater flooding annually.
Natural Systems Protection F21 Preserve Floodplains as Open Space Use the Annual Chance Depth Grids to develop stream buffers 10% shown here
Education and Awareness Programs F22 Increase Awareness of Flood Risk and Safety Conduct Open Houses Use CSLF or Polygon areas of changes to 1% and 0.2% annual chance floodplains and floodways. Polygons will contain attributes that indicate regulatory zone changes as well as contributing engineering factors (e.g. changes to peak discharges, modeling methodology). Structures: the total estimated count of affected buildings within the area of change Population: the total estimated affected population within the area of change Changes Since Last FIRM Data
Education and Awareness Programs F23 Educate Property Owners about Flood Mitigation Techniques Percent Chance of Flooding over a 30-year Period Grid A grid dataset that represents the percent chance of flooding within a 30- year period for locations along a flooding source We can use this dataset to focus communications with Homeowners to purchase flood insurance policies
Using the RiskMAP Products: 30% Annual Chance For structures in the SFHA, the % Annual Chance Grid is a great tool to describe risk to the homeowner Map Tips work great This structure would have an estimated 95.8% chance of flooding over the life of a 30 year mortgage Using Extract Values to Points Tool Target outreach for Flood Insurance to structures with more than a 50% chance of flooding in 30 years.
Emergency Services There are 29 School Facilities in the County in this Structures file. For structures in the SFHA, the Depth Grid is a great tool to describe risk to the Emergency Managers or School Official Using Extract Values to Points Tool Consider relocation of structures in the floodplain An Intersection of the MODOT roads file with the stream centerline file result in 226 bridges/culverts in the county that cross the SFHA. Are there any schools near those crossing? These crossings need to be considered for school bus routing-rerouting during storm events.
The Mitigation Action Tracker Web based collection tool: Identify Areas of Mitigation Interest (AoMI) and actions Document & Organize mitigation activities Communicate progress on mitigation activities Identify point(s) of contact for each mitigation action https://mat.msc.fema.gov/about.aspx 45
Risk MAP Performance Measures Action Measure 1 is defined as the percentage of population where Risk MAP helped identify new strategies or improved current planned mitigation actions in direct collaboration with communities. Action Measure 2 is defined as the percentage of population that has advanced identified mitigation actions. This includes communities that began implementing mitigation actions, either from their Mitigation Plan or from new strategies identified during Risk MAP. Status Q2 Number of Mitigation Actions in MO AM1- Identified 127 AM2-In Progress 2 AM2- Completed 7 Grand Total 136 46