On 5/11/12 5:23 AM, swingbyte wrote:
s disappointing!

for that, you need a real surveyor who can provide a "legally accepted"
measurement.  Someone who can
a) know from the flood level definition what vertical datum they are
using (probably NOT something normal in the geodesy world)
b) knows the legalities of establishing the difference

The mechanics of surveying (leveling in this case) are straightforward
to learn.  The legalities and local practices in documentation are not.
This is what getting a Land Surveyor's license is all about.

There's also a question of what the legal height of your house is,
relative to the property (from a flood insurance standpoint).  They
might have some arbitrary offset in the rules. Sort of like how baseline
electrical power consumption is actually about 2/3 of the expected
minimum consumption in the area for a given size house and appliances
(e.g. nobody is likely to consume less than baseline)

There are some mortgage servicers, by the way, who take property
addresses that have been geolocated and FEMA flood plain definition maps
to determine whether you definitely don't, definitely do, or just might
need flood insurance.  The maps change (as does the geolocation). From
what I understand, about 3-5% of the properties scanned require some
sort of manual intervention (maybe the address doesn't geolocate, or
it's right on the line, or)

On 5/11/12 5:54 AM, Chuck Harris wrote:

I have been informed (in the last 5 minutes) that whether you are in a
flood plain, these days, are determined almost entirely by the
geographic position of your property on the FEMA flood plain map.  (at
least as far as lenders and HO insurance goes) FEMAs maps may or may not
align with USGS maps.  They almost certainly do NOT align with the
county recorder's maps.

If you're in an area where FEMA doesn't issue maps then it's something
else, and USGS or local maps may determine.  But I notice from the FEMA
Flood Map server that they cover even things up in the mountains (e.g.
Alpine county in California)

The FEMA maps didn't exist the last time I did this.  I would think
it likely that the building and planning commission office for his
area would have the appropriate maps, as establishing that the proposed
house's location is outside of the the 100 year flood plane, is a
necessary check mark in getting a building permit.

-Chuck Harris

Jim Lux wrote:

On 5/11/2012 6:46 AM, Jim Lux wrote:

Actually, The percentage can be higher.  The scale of the FEMA flood
panels are usually around 1=2000.  Some of the older panels were
1=4000.  The newest panels can be around 1=1000 (approx 5" to the
section).  Horizontal scale is not the problem, it's the vertical
scale.  Also how the stream bed profile was established (surveyed).
There can be a lot of change in the real world compared to was gets
plotted on the panel and in the profile.  When there is an obvious
discrepancy between the two (mapped profile and real world) a registered
surveyor or engineer must be called in to reconcile the difference.  The
cost for doing this might seem high, but when compared to the cost of
flood insurance paid over the life of a mortgage, it's very cheep.

Just my 2 cents worth. . .

Randy Hunt, retired Engineering Technician, Flood Plain Administrator
(32years)

On 5/11/2012 6:57 AM, Jim Lux wrote:

The FEMA flood panels are the Minimum standard that must be met.  The
Local Agency can be much more stringent in its' requirements.  They will
usually have a Flood Ordinance established.

Randy Hunt