Construction in Flood Zones - Substantial Improvement / Damage

If your home or business is below the 100-year flood elevation, the City of San Leandro has flood damage prevention regulations that may affect how you remodel, renovate, or add on to your building. If your home or business sustained structural and/or interior damage, these regulations may affect how you rebuild. The National Flood Insurance Program (NFIP) requires these regulations be adhered to in order to protect you and your property from future flood damage. The City must adopt and enforce flood protection laws in order for federally backed flood insurance to be made available to community residents and property owners. Information about Substantial Improvement and Substantial Damage can be found in FEMA Unit 8 (PDF).

  • Substantial Damage means damage of any origin sustained by a structure whereby the cost of restoring the structure to its "before damage" condition would equal or exceed 50% of the market value or replacement cost of the structure before the damage occurred. Please note: The cost of the repairs must include all costs necessary to repair the structure to its "before damage" condition.
  • Substantial Improvement means any reconstruction, rehabilitation, addition or other improvement of a structure, the cost of which equals or exceeds 50% of the market value of the structure before the "start of construction" of the improvement.

City Compliance Regulations

If a building is "substantially damaged" or "substantially improved" it must be brought into compliance with City of San Leandro's damage prevention regulations, including elevating the building to or above the 100-year flood elevation.

Further Information

For additional questions about permits and construction in the flood zone, please contact the Division of Building and Safety at 510-577-3420.