440 Flood Data Maintenance
400 Mapping and Regulations

440
Flood Data Maintenance

Many floodplain management functions rely on up-to-date and accurate data. In this activity, communities are awarded credits for taking steps to maintain data continuity and to encourage data accessibility.

442.a
Additional map data (AMD)

Flood data maintenance systems can help you better track the maps and datasets that your community utilizes to plan.

Level of effort = moderate

Overview

This element awards credits to communities utilizing flood data maintenance systems. It's wide-ranging, there are 13 subelements, so you should take stock of your existing mapping systems (both digital and analog) and determine what points you qualify for using the Credit Calculations section below. In general, you can receive credit for the following subelements:

  • AMD1: using an electronic system to manage your flood map digitally (typically this is a GIS software)
  • AMD2: using a database system that maintains flood data for each property in your community
  • AMD3 - AMD13: using map overlays to communicate flood information (such as layering the Special Flood Hazard Area (SFHA) on top of the zoning map, or a map change overlaid on the Flood Insurance Risk Map (FIRM)).

For credit, your community must use the data systems you put into place regularly, and update the maps annually (at least). Maps must also be shared with FEMA annually.

Considerations

This element requires significant GIS expertise. AMD1 is a prerequisite for subsequent AMD subelement credits.

Documentation

To receive credits for this element, you must provide:

  • Copies of the maps
  • The impact adjustment map

Credit Calculation

Max: 160 for the following:

Element Maximum Credits
AMD1 - Mapping the SFHA, community limits, streets, and lot or parcel boundaries 20
AMD2 - Mapping the buildings in the community, and updating the map to reflect new construction 26
AMD3 - Mapping floodways or coastal high hazard areas 12
AMD4 - Mapping base flood elevations (BFEs) 12
AMD5 - Mapping FIRM zone information (AE, VE, etc.) 10
AMD6 - Mapping the 500 year floodplain (including parcel information) 10
AMD7 - Mapping other hazards in the community (landslides, subsidence, etc.) 12
AMD8a - Mapping topographic contours 8
AMD8b - Mapping topographic contours at a smaller interval than the USGS maps 12
AMD9 - Including floodplain information in the tax assessment database 6
AMD10 - Mapping all FIRMs since the community’s application to the CRS 6
AMD11 - Mapping layers from Hazus or repetitive loss areas 8
AMD12 - Mapping natural floodplain functions (wetlands, etc.) 14
AMD13 - Mapping building elevation data 14

The impact adjustment is calculated as follows:

Mapped area of the Special Flood Hazard Area (SFHA) / Total Special Flood Hazard Area (SFHA)

442.b
FIRM maintenance (FM)

Do you have a system for managing old Flood Insurance Rate Maps (FIRMs)?

Level of effort = low

Overview

For this element, you can receive credit for keeping and making available copies of old Flood Insurance Rate Maps (FIRMs), Flood Insurance Studies, and Flood Boundary Floodway Maps. Credits are also awarded for including Flood Hazard Boundary Maps (pre-FIRM) in this collection. To compile your database, you can access older versions of these maps at FEMA’s Flood Map Service Center. For credit, maps can be stored in paper or digital format but must be made available to members of your community if requested.

Considerations

This element requires minimal effort and time, as most communities already have copies of past flood insurance maps, or can easily obtain them from FEMA. Unfortunately, you do not get credit if the Flood Insurance Rate Map (FIRM) has never changed.

Documentation

To receive credit for this element, you must provide the indexes from all maps on file and the cover of each Flood Insurance Study.

Credit Calculation

Max: 15

A maximum of 12 credits can be awarded for maintaining all copies of relevant maps. An additional 3 credits are awarded for copies of the Flood Hazard Boundary maps. There is no impact adjustment for this element.

442.c
Benchmark maintenance (BMM)

Benchmarks are crucial to accurate surveying and you can receive credits for maintaining them.

Level of effort = low

Overview

Benchmarks are elevation references used by surveyors to produce Elevation Certificates and conduct land surveys. Well-maintained and numerous benchmarks are crucial for producing accurate flood risk analysis. This element incentivizes communities to invest in benchmarks. It is composed of two subelements:

  • BMM1: you can get credit for creating a program that maintains benchmarks that meet the prerequisites of the National Spatial Reference System (NSRS). Benchmarks that were located in the last 5 years within a mile of the Special Flood Hazard Area (SFHA) can be included in this program.
  • BMM2: you can also get credit for maintaining a network of Continuously Operating Reference Stations (CORS) GPS surveying stations (at least three CORS 30 miles of the Special Flood Hazard Area (SFHA)).

Considerations

If your community must find or create benchmarks, this element can become quite complex.

Documentation

To receive credit for this element, you must provide:

  • The list of benchmarks and/or Continuously Operating Reference Stations (CORS)
  • The applicable data from the National Spatial Reference System (NSRS) or community database (printout of datasheets or URL, or a signed statement by the surveyor)
  • An impact adjustment map showing the Special Flood Hazard Area (SFHA) as well as the benchmarks

Credit Calculation

Max: 27

A maximum of 27 credits can be awarded for BMM1 (one or more benchmarks). Alternatively, a maximum of 27 credits can be awarded for BMM2 (3 Continuously Operating Reference Stations (CORS) within 30 miles of the Special Flood Hazard Area (SFHA)).

The impact adjustment for BMM1 is calculated as follows:

Benchmarked area within one mile of the Special Flood Hazard Area (SFHA) / Total Special Flood Hazard Area (SFHA)

The impact adjustment for BMM2 is calculated as follows:

Area of the Special Flood Hazard Area (SFHA) within 30 miles of 3 Continuously Operating Reference Stations (CORS) / Total Special Flood Hazard Area (SFHA)

442.d
Erosion data maintenance (EDM)

This element awards credits for collecting erosion data from your community's shoreline.

Level of effort = moderate

Overview

Your community can receive credit for updating coastal erosion information and regulating development in areas susceptible to erosion. To record erosion and track changes, you can reference marks (less than or equal to a 1/2 mile apart) or take aerial photographs (this will net you fewer credits, see Credit Calculation below). To maintain credits awarded, you must update the data at least every 5 years.

Considerations

Erosion data is not usually readily available so this element can be challenging for some communities. Additionally, the entire shoreline within the boundaries of your community must be utilized in the erosion study. This can be difficult depending on your community's specific geography. There is a prerequisite for this element: you must receive credit for regulating for erosion under 432.n Coastal erosion hazard regulations (CER).

Documentation

To receive credit for this element, provide:

  • A description of the erosion recording method
  • Documentation that the demonstrates that erosion rates are updated at least every 5 years

Credit Calculation

Max: 20

20 credits are awarded for recording erosion using reference marks and updating the references every 5 years. Alternatively, 10 credits can be awarded for recording erosion using aerial photographs. There is no impact adjustment for this element.

This CRS guide was produced by CRS professionals and Certified Floodplain Managers to help you navigate the Community Rating System. It is not meant to replace FEMA's official CRS Coordinator's Manual, nor should it supersede the instructions given by your ISO/CRS Specialist.

For additional resources, visit https://crsresources.org/ .