Evaluating the Effectiveness of Local Mitigation Activities in Reducing Flood Losses

Highfield, W. E. and Brody, S. D., 2013. Natural Hazards Review

Original research (primary data)
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In an effort to counteract mounting flood losses, FEMA introduced the Community Rating System (CRS) in 1990 as a way to encourage local jurisdictions to exceed the National Flood Insurance Program’s minimum standard for floodplain management. While the program has grown since its inception, there is little understanding of the degree to which mitigation activities have reduced flood-related losses to buildings and their contents over time. The effectiveness gap is addressed through the longitudinal statistical analysis of 450 CRS-participating communities. For each selected community, CRS point totals are tracked on a yearly basis over an 11-year study period from 1999 to 2009 and their impacts on insured loss claim payments based on claim type and floodplain location are tested. Results indicate that three CRS activities, freeboard requirements, open space protection, and flood protection, significantly reduce flood damage.

Case studies

Basic information

  • Case ID: INT-084-1
  • Intervention type: Protection
  • Intervention description:

    Open Space Protection: As an overall approach, open space protection offers a policy vehicle for keeping structures out of the most vulnerable areas where they are most likely to incur damage while also conserving other beneficial services provided by the natural environment. this is from the FEMA program which intends to incentivize the protection of open space FEMA's CRS program awards credit points to communities for flood protection measures, including open space preservation, thus it incentivizes the preservation of open space

  • Landscape/sea scape ecosystem management: No
  • Climate change impacts Effect of Nbs on CCI Effect measures
    Freshwater flooding  Positive Average amount ($) saved from avoided damages based on insured loss claim payments
  • Approach implemented in the field: Yes
  • Specific location:

    communities across the US - 450 CRS-participating communities were selected as a nationally representative sample

  • Country: United States of America
  • Habitat/Biome type: Ecosystem not specified |
  • Issue specific term: Not applicable


  • Notes on intervention effectivness: effectiveness inferred from explanatory statistical modelling alternative comparison unclear because authors do not make conclusion as to which intervention is ultimately superior and conclude that the best option will likely be a combination of them all
  • Is the assessment original?: Yes
  • Broadtype of intervention considered: Engineered approach(s)
  • Compare effectivness?: Yes
  • Compared to the non-NBS approach: Unclear
  • Report greenhouse gas mitigation?: No
  • Impacts on GHG: Not applicable
  • Assess outcomes of the intervention on natural ecosystems: No
  • Impacts for the ecosystem: Not reported
  • Ecosystem measures:
  • Assess outcomes of the intervention on people: No
  • Impacts for people: Not reported
  • People measures:
  • Considers economic costs: Yes
  • Economic appraisal conducted: No
  • Economic appraisal described:
  • Economic costs of alternative considered: No
  • Compared to an alternative: Not reported

Evaluation methodology

  • Type of data: Quantitative
  • Is it experimental: No
  • Experimental evalution done: Not applicable
  • Non-experimental evalution done: Empirical case study
  • Study is systematic: