BUILDING WITHIN A FLOODPLAIN

Building in the floodplain can have serious consequences, including:

• Increase in overall flooded area: Buildings and other structures in the floodplain displace flood waters, pushing overflow further out into the watershed and affecting lands and buildings that would not be at risk otherwise.
• Greater financial losses through property damage when flooding occurs.
• Increase in risks to human safety: Deaths and injuries from drowning, being trapped in vulnerable structures, or being struck by flood debris all increase once floodplains are developed.

Regulations for Building in the Floodplain

Flooding is a natural process. Reducing property damage and protecting human safety when flooding does occur are two goals of floodplain management. There are many policies and regulations in place regarding the protection and management of floodplains.

The State, Parish, and City all have regulations pertaining to floodplains and floodplain development. Some of these regulations are required for participants in the National Flood Insurance Program (NFIP).

General Criteria for floodplain development

• All development in the City of Lafayette & Unincorporated Lafayette Parish require permits from Development & Planning Department.
• LCG requires no net loss of flood storage capacity. This is called “Zero Net Fill,” also called “Compensatory Storage.”

Zero Net Fill was adopted in November 2017, which is meant to preserve the ability of the floodplain to store water. Compensatory storage means that loss of flood storage due to buildings or fill dirt in the floodplain is compensated for by providing an equal volume of storage to replace what is lost. In other words, if you bring one bucket (fill) in - you need to take one bucket out.

Standards for development in the floodway

• The NFIP recommends that all development in the floodway be discouraged.
• For all development that encroaches the floodway, the developer must submit a Certificate of No-Rise certifying that the development will not raise the base flood elevation (BFE).
• Projects that will alter the floodway boundary will require a CLOMR prior to approval.
• A list of surveyors and engineers local to the Lafayette area can be provided upon request.

Standards for new buildings in flood fringe

• The lowest floor of any new residential structure, including mechanical and electrical equipment servicing the structure, must be elevated to an elevation 1 foot above the base flood elevation.
• The lowest floor of any new non-residential structure, including mechanical and electrical equipment servicing the structure, must be elevated or flood-proofed to an elevation 1 foot above the base flood elevation.

Standards for substantially improved buildings

• All structures that are improved in the floodplain and floodway must meet standards for new buildings if:
  • the value of the improvements, over a cumulative rolling ten-year period, exceeds 50% of the market value of the structure.
  • additions to the structure exceed 50% of the original structure’s square footage.
• Note: historic structures are exempt from the substantial improvement requirement, provided that the historic character of the structure is maintained.

The Lafayette Consolidated Government committed to enforcing these flood damage protection standards by adoption of a floodplain resolution on November 5, 2018. The ordinance was required for continued participation in the NFIP, and so that citizens of Lafayette Parish may purchase flood insurance through the NFIP. 

Additional resources

A Flood Insurance Survey (FIS) is a compilation and presentation of flood risk data for flood hazard areas. The FIS report contains detailed flood elevation data in flood profiles and data tables.

Lafayette Parish Flood Insurance Study (April 3, 2012)

• Vol. 1 (PDF) - FIS Vol. 1 includes discharge and floodway data
• Vol. 2 (PDF) - FIS Vol. 2 includes the flood profiles

The Lafayette Consolidated Government Floodplain Administrator also maintains elevation and floodproofing certificates for all new buildings and substantial improved structures located in the floodplain.  Elevation and floodproofing certificates for these structures can be found on this elevation certificate list, or can be provided upon request by contacting John Broyles by email at cpboudreaux@LafayetteLA.gov or 337-291-8468.