Potomac Waterfront Flood Mitigation Study - City of Alexandria

Overview of Flood Mitigation Measures
To receive CRS full credit of 45 points, the community must have a system to track
improvements for at least 10 years. However, Alexandria could receive 25 CRS points if the
records are accessible for at least five years.
This element may require no specific ordinance language, but simply a policy decision to
interpret the 50 percent improvement threshold as cumulative. In such cases, as required by
the CRS program, documentation must include a legal opinion or directive from the legal
counsel stating how the ordinance is to be interpreted. In any event, the City would need to
maintain permit records by parcel number or address, so that the history of improvements or
repairs to a particular structure is checked before the next permit is issued.
This element requires that more structures be brought into compliance with the NFIP, thereby
lowering costs from flood damages and decreasing flood insurance rates. There will be an
increased cost for homeowners and business owners who reach the substantial improvement
threshold earlier and will be required to bring their structures into compliance with the
floodplain regulations. For the City, costs would be associated with changing the zoning
ordinances and policies and educating permitting officials on the change.
However, one difficulty expressed by the City’s staff is evaluating the value of the
improvement in comparison to the value of the structure. The City’s current ordinance is
written based on NFIP requirements, which calculate the improvement as a percent of
“market value of the structure.” If the City were to change the definition within the ordinance
to reflect different measurement criteria, such as square footage, the change may not meet
NFIP requirements. Therefore, it is recommended that the City consult with FEMA regarding
the method of measuring cumulative improvement values.
Lower Substantial Improvements – This element has the effect of requiring more
structures to come into compliance after a disaster, because damage repair is included in
"improvements" under the NFIP rules. The City of Alexandria already includes a 50 percent
substantial improvement threshold. To receive CRS credit for the Lower Substantial
Improvement Threshold, the City would need to lower the threshold to less than 50 percent.
For instance, if the regulatory threshold was lowered to 49 percent, the City would qualify
for an additional 10 points. If the threshold was lowered to 39 percent, the City would qualify
for an additional 50 points.
In a manner similar to the cumulative substantial damages element, this element provides
more flooding protection by requiring more structures be brought into compliance with the
NFIP, thereby lowering costs from damages and decreasing flood insurance rates. However,
it results in an increased cost for homeowners and business owners who reach the lower
substantial improvements threshold earlier and will be required to bring their structures into
compliance with the flood maps. Again, the only costs to the City would be associated with
changing the zoning ordinances if necessary and educating permitting officials on the
change.
Protection of Critical Facilities – CRS credit is provided only if regulatory language
protects critical facilities. FEMA defines types of critical facilities as follows:
Structures or facilities that produce, use, or store highly volatile, flammable, explosive,
toxic and/or water-reactive materials
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