Tying Flood Insurance to Flood Risk for Low-Lying Structures in the Floodplain (2015) / Chapter Skim
Currently Skimming:
5 Alternative Approaches and Implementation
5 Alternative Approaches and Implementation
Pages 49-60
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 49... ...
The com m CURRENT NFIP METHODS mittee considered both incremental changes to current NFIP methods and different approaches, which would The first task of the committee was to review require research, development, and standardization; current NFIP methods for calculating risk-based new data collection; and user training. premiums for negatively elevated structures, including risk analysis, flood maps, and engineering data (see Incremental Changes to Current NFIP Methods Box 1.1)
|
From page 50... ...
defined rate classes and premiums that better reflect the local flood hazard. Conclusion 5. Levees may reduce the flood risk for negatively elevated structures, even if they do Conclusion 3. NFIP claims data for a given depth of not meet NFIP standards for protection against flooding are highly variable, suggesting that inunda- the 1 percent annual chance exceedance flood.
|
From page 51... ...
The effort to modify the procedure and use the analysis tools and improved data collection and results in the average annual loss calculation is likely management capabilities, enable the development to be moderate. The procedure is already being applied and use of comprehensive risk assessment methods, for the 1 percent annual chance exceedance flood, and which could improve NFIP estimates of flood loss.
|
From page 52... ...
tribution of flood losses and the average annual For example, it will be important to describe loss and to assess risk for individual structures, the distribution about the mean 50, 10, 1, and communities, or the entire portfolio of insured 0.2 percent annual chance exceedance inunda structures. The procedures and software would tion depths.
|
From page 53... ...
Substane levated structures requires, at a minimum, structure tial cost savings are possible if large groups of structures elevation data, water surface elevations for frequent (e.g., a neighborhood) are surveyed with common land flood events, and new information on structure surveying methods.
|
From page 54... ...
54 FLOOD INSURANCE FOR LOW-LYING STRUCTURES IN THE FLOODPLAIN FIGURE 5.1 Example of an Elevation Certificate, with identifying features redacted, for a negatively elevated house built in 1970 in Isleton, California. SOURCE: Courtesy of George Booth, Senior5.1 page 1.eps R02820 Fig Civil Engineer, Sacramento County, California.
|
From page 55... ...
ALTERNATIVE APPROACHES AND IMPLEMENTATION 55 FIGURE 5.1 Continued R02820 Fig 5.1 page 2.eps
|
From page 56... ...
over the methods used to determine structure replacereport found that lidar measurements would have to ment cost values and the insufficient quality control be supplemented with on-site precise survey mea- of NFIP claims data undermine the accuracy of NFIP surements. Cross-checking structure elevations from flood loss estimates and premium adjustments.
|
From page 57... ...
.5 The fifth task of the committee was to discuss feasibility, implementation, and cost of underwriting Cost risk-based premiums for negatively elevated structures, including a comparison of factors used to set risk-based As discussed above and summarized in Table 5.1, premiums. A detailed assessment of implementation incremental changes to current NFIP methods can be options was beyond the capability of the committee accomplished at low or moderate cost.
|
From page 58... ...
including other drivers, and depth–damage independent of the commercial data to validate or Structure elevations expand damage predictors if LOW effort to functions if credibility USACE damage on structure replace Elevation are determined using appropriate investigate commercial weighting scheme is models elevation Certificates ground surveys data on structure to be enhanced Require property owners elevation Use a larger set of HIGH effort to obtain Elevation Data from vehicle- damage predictors to use lidar to Certificates HIGH effort to use mounted lidar to to capture the estimate structure lidar to estimate validate or replace relevant drivers of elevations Investigate using structure elevations Elevation Certificates damage commercial sources of structure elevation data Investigate using vehicle-mounted Investigate using vehicle- lidar to estimate mounted lidar to estimate lowest floor lowest floor elevation elevation Exposure Use structure Obtain consistent structure LOW effort to obtain Accurate and Same as Same as Same as incremental replacement values replacement values by accurate structure consistent structure incremental incremental change reported by insurance setting standards for replacement values replacement values change change agents insurance companies or purchasing commercial data
|
From page 59... ...
if the insured value is too low at the time of loss Deductibles Minimum and Increase the minimum LOW effort to make None Same as Same as Same as incremental maximum deductibles deductible administrative changes incremental incremental change are offered for change change structures and Account for differences contents in flood risk and structure values when calculating premium discounts Express deductibles as a percentage of the insured value, rather than fixed value a A low level of effort means that existing resources can be reapplied to make the change (e.g., a few person months)
|
From page 60... ...
, then the NFIP could implement the incremental changes to PELV, DELV, and levee performance. Otherwise, taking the time and effort to implement a comprehensive risk analysis methodology and to develop site-specific flood hazard descriptions, models that predict damage from multiple drivers, and probabilistic models that describe the performance of risk reduction measures would yield a better assessment of flood losses, and thereby provide a firmer foundation for rate setting.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.