jar546
Forum Coordinator
Base Flood Elevation (BFE) and Design Flood Elevation (DFE) are the two important elevation standards under BFE that give guidance to critical facilities directly or indirectly.
While these two definitions are key in the context of cutting the damage that may arise from flooding and ensuring resilience to buildings, the two terms differ in that they are used for different purposes and set various levels of protection against different types of floods.
Base Flood Elevation (BFE):
The Starting Line BFE is the elevation up to which floodwaters are expected to rise in a "100-year flood," otherwise expressed as a flood that has a 1% chance of being equaled or exceeded in any given year. This is the minimum elevation that, for very critical reference, all construction and flood insurance must give due consideration. Under no circumstances can it fall below this minimum baseline standard for participating communities, as adopted by the National Flood Insurance Program (NFIP). In essence, the BFE establishes the level from which the lowest elevation is shown below where the construction should begin in order to assure that the critical building components do not have flood damage.
Design Flood Elevation (DFE):
The DFE takes the concept of flood resilience a step further. It is the elevation a building must be raised to, considering the BFE and, also, freeboard—a factor of safety. Freeboard is an added level from the base flood elevation, allowed for in the case of such uncertainties as local conditions not reflected on the BFE, future environmental changes, and even flooding of higher elevation levels than anticipated.
In simple language, DFE offers a more conservative elevation standard that gives an added layer of assurance against damage from flooding.
The Practical Implications:
What does this mean for construction in flood-prone areas?
Where BFE reaches, control is exercised at the minimum level, and by adopting DFE, it works to an additional good engineering practice in building up durability and resilience of structures to floods. It further sponsors the community and builders towards new construction and substantial improvement in adopting the DFE, pointing out that the additional upfront usually comes from long-term cost reduction by reducing flood damages, decreasing insurance premiums, and ensuring continued occupancy post-flood. This will also show the potential attitude toward urban planning and construction that is more sustainable and resilient, recognizing the increasing difficulties of changing conditions of climate and sea level.
Building beyond these minimum requirements serves to protect communities, citizens, and infrastructure and economies from cataclysmic disaster due to flood events. Conclusion Of prime importance is how this difference affects anybody, either engaged in the construction and insuring or regulation aspects of building in flood hazard areas. We will only be equipped to handle such present standards by aiming at the DFE, but we will also be complacent in readiness for the eventualities and the view towards being proactive in floodplain management and construction.
While these two definitions are key in the context of cutting the damage that may arise from flooding and ensuring resilience to buildings, the two terms differ in that they are used for different purposes and set various levels of protection against different types of floods.
Base Flood Elevation (BFE):
The Starting Line BFE is the elevation up to which floodwaters are expected to rise in a "100-year flood," otherwise expressed as a flood that has a 1% chance of being equaled or exceeded in any given year. This is the minimum elevation that, for very critical reference, all construction and flood insurance must give due consideration. Under no circumstances can it fall below this minimum baseline standard for participating communities, as adopted by the National Flood Insurance Program (NFIP). In essence, the BFE establishes the level from which the lowest elevation is shown below where the construction should begin in order to assure that the critical building components do not have flood damage.
Design Flood Elevation (DFE):
The DFE takes the concept of flood resilience a step further. It is the elevation a building must be raised to, considering the BFE and, also, freeboard—a factor of safety. Freeboard is an added level from the base flood elevation, allowed for in the case of such uncertainties as local conditions not reflected on the BFE, future environmental changes, and even flooding of higher elevation levels than anticipated.
In simple language, DFE offers a more conservative elevation standard that gives an added layer of assurance against damage from flooding.
The Practical Implications:
What does this mean for construction in flood-prone areas?
Where BFE reaches, control is exercised at the minimum level, and by adopting DFE, it works to an additional good engineering practice in building up durability and resilience of structures to floods. It further sponsors the community and builders towards new construction and substantial improvement in adopting the DFE, pointing out that the additional upfront usually comes from long-term cost reduction by reducing flood damages, decreasing insurance premiums, and ensuring continued occupancy post-flood. This will also show the potential attitude toward urban planning and construction that is more sustainable and resilient, recognizing the increasing difficulties of changing conditions of climate and sea level.
Building beyond these minimum requirements serves to protect communities, citizens, and infrastructure and economies from cataclysmic disaster due to flood events. Conclusion Of prime importance is how this difference affects anybody, either engaged in the construction and insuring or regulation aspects of building in flood hazard areas. We will only be equipped to handle such present standards by aiming at the DFE, but we will also be complacent in readiness for the eventualities and the view towards being proactive in floodplain management and construction.