Building in Flood Zone A

That is one of the simple ways to satisfy many people requesting a definition. Basically, if it doesn't fall within the colored area, it is considered to be out regardless of elevation. If it does, it is in, regardless of elevation, until such time as a LOMA is submitted and approved.

Common sense does not apply to flood plane rationale.

Common sense only needs to be applied by the homeowner wishing to not have flood waters touching any part of his home. To my way of thinking, that means to build it somewhere else.

For community and insurance purposes it's the FPA call to locate the zone line. From what I am reading a BFE is not necessary. He we use distances from roads or other topo features. Of course the bank will use their own company and whatever information they provide eventhough they may disagree with the FPA.

If I was the home owner I would build outside of the A zone and carry insurance. If the zone is expanded to incluce his house the rates stay the same. On the other hand if he gets insurnce for the first time the zone is expanded to include his house then an elev. certi will need to be done and his rates will be based upon the EC. If he is below the BFE then the rates can be very high.

I have found that often the FEMA maps follow the contour lines on the quad maps.
I would suggest building above that line no matter what, much like Lamon said, if the zone is expanded it can get very costly.

Forrest,
Check out this manual:

The Zone A Manual: Managing Floodplain Development in Approximate Zone A Areas

The Federal Emergency Management Agency (FEMA) developed the Zone A Manual, also referred to as FEMA 265, to provide engineering guidelines for determining Base Flood Elevations in Special Flood Hazard Areas that were studied by approximate methods only, and are labeled Zone A on the effective National Flood Insurance Program (NFIP) map. The Quick-2 User's Guide is also included in the appendices of this manual.

http://www.fema.gov/plan/prevent/fhm/dl_zonea.shtm

Hope this helps,
DDSM

I strongly suggest a BFE be determined by a qualified practitioner.

Note here is what FEMA says about comparing contours to "estimate" the relationship between a structure and the 1% flood:

"Simplified methods may not be used by the community to complete an elevation certificate used for flood insurance rating. Communities must use the detailed methodologies described in this section or other methods comparable to those in a flood insurance study for completing the elevation certificate."

There is a reason for caution. The flood boundary in a zone A is approximate and FEMA is not hanging their hat on what the BFE is. The boundary they show is also very approximate and is not adequate for determining the relationship between a structure and the 1% flood. Anyone who tries to estimate a BFE in a Zone A without doing the hydraulic and hydrologic analysis is fooling themselves and their client.

Unfortunately, too many try to do a best job estimating based on contours from the FIRM where the BFE needs to be more accurately determined. The only time this should be attempted is where the structure is without a doubt outside the flood plain or flood way and the difference in elevation is great enough to be completely obvious.

Never, ever use the contours on a zone A if there is any question and the FPA is unwilling to provide a determination.

I'm with Holy Cow. It's the line on the map. The BFE only comes into play when you need to a certificate and/or a LOMA.

I know it's nuts, but it's Holy.....