Thanks to my fellow engineer Chad Stevens for his recent clarifications on East Baton Rouge floodplain fill requirements. Please allow me to add six more. One, in low-lying areas adjacent to very mildly sloped streams like Bayou Fountain, there is no such thing — hydrologically speaking — as a portion designated with a single line as "a floodplain" or "the floodplain." Rather, nearly the entire watershed area is subject to a range of inundation chances.
Two, like most communities around the nation that have adopted floodplain development, regulations based on the federal National Flood Insurance Program, our parish does not regulate the entire "floodplain" (potential inundation area) of streams like Bayou Fountain — only the portion below the estimated level of a once in 100-year chance flood. Three, we all need to understand that this assigned NFIP level floodplain, while very useful, has so much inherent uncertainty that it really should be regarded at best as a "good scientific guesstimate."
Four, when the guesstimate is decades old it is very likely to be low to begin with. Five, a floodplain level with a rare-sounding "1 in 100 chance each year" is really not an especially rare level at all when considering the typical multiple decades of re-exposure by most property stakeholders.
Lastly and most importantly, what some may think to be benign fill (and other activities) above the "regulated portion of the floodplain" can actually be having a significant financial impact to others in the watershed area.