No BFE

Long Steps

IF no BFE is established, then you are up a creek. What happens is a community, town, or group of folks HIRE an engineering company, to do hydrology, as in TOTAL acres, and max rainfall in the last 100 yrs, in a time frame, and the plug all this in, with data from the soil conservation services, and come up with a BFE. IF no bfe exists, then they often wind up paying max flood plain fees.

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Tell her that you never had a conversation with her.................but to call you back after she magically raises/compacts properly the lot about 10 feet deep with high quality fill material. And, oh yeah, again she never had a conversation with you but she had better check first with the County Sanitarian or whatever that position is called to determine restrictions on construction of sanitary lagoons or septic systems NEAR a flood plain. Key elements being you never told her anything.

Born on a hilltop, live on a hilltop, plan to die on a hilltop and be buried on a hilltop.

Do it all the time, most areas here don't have BFE's. She hires an engineer, the engineer may have you do cross sections and you give them the data and they calculate the BFE, it's not something for a surveyor to do. Then you go through the filings with FEMA. She may be in after it's all done and have to pay anyway.

But if it's flat and the flood plain is on the lot why in the world build there, I can see when the new maps miss a high point but otherwise why live with flooding fears each year?

This might shed some light

http://www.ce.utexas.edu/prof/maidment/grad/tate/research/RASExercise/webfiles/hecras.html

There are numerous unanswered questions here. I assume you have verified the structure lies in the SFHA? FEMA adopted great guidelines for objective location of the boundaries in 2007. If inside zone A with no BFE or depth of flooding it's a flowchart of options. Hiring an engineer is way down the list if you have the expertise. Nothing wrong with hiring one but I don't do it if I don't have to....

Odds are that this lady does not want to spend the money to hire an engineer. If she did, the cost might be more than the land is worth.

For a few hundred dollars she might hire you to do enough field work to determione the elevation of the site. Prepare a MT-EZ form and request FEMA establish a BFE.
It might turn out that placing a home there is not possible.

Some historical flood data would be helpful for FEMA. FEMA will put a lot of stock in historical data.

This is a poor's man method of getting a BFE.

Would you be willing to post a link or address for the flow chart? Thanks!

In Kentucky, the division of water will provide a BFE in some instances.

Sorry, but that method probably won't work. Had a lady call a while back with a similar issue only she is actually on sort of a hill but clearly in the Zone A shaded area. Primed her with all sorts of great information and then had her call FEMA. They were very nice and wanted to be helpful but refused to offer to issue a BFE without a full workup including cross-section, which from her location is about 3000 feet long. They told her not to waste her time or theirs sending in a form without doing all their work for them except, of course, determining the BFE.

I thought there was a paper on FEMA's website about just that issue if i remember correct they said to check with other sources.( Army Corps, DNR, DOT) If you can get them the source of the 100 year flood determination they may accept it. section IV

http://www.fema.gov/media-library-data/20130726-1545-20490-4110/frm_zna.pdf

http://www.fema.gov/media-library/assets/documents/7273?id=2215

In some regions, like FEMA Region 7, they will show a BFA (Base Flood Approximate)on the Maps. FEMA usually accepts that for EC's. They don't do that here in Region 5 and I don't know what FEMA Region you're in.

If it were me I would use FEMAS's Quick-2 software to get a BFE

http://www.fema.gov/national-flood-insurance-program-flood-hazard-mapping/quick-2-version-20

I would also use USGS Streamstats (Tennessee is a Streamstats State)to get the stream discharge (Q) that you will need for Quick-2

http://water.usgs.gov/osw/streamstats/ssonline.html

But, although I'm not a PE, I have had some fairly extensive Hydraulic and Hydrologic training, and also program specific training in Quick-2.

It's not really for the novice, but it's also not rocket science either. But if you have no H&H experience, you probably shouldn't go there until you have gained some.

I do residential elevation certificates all the time in zone A with no established BFE. The county flood management dept states that the bottom of the main frame (or top of concrete floor) must be 2 ft above HANG.

So you set grade for them based on that. Return when the house is built and finish.

I was involved a while back on some commercial property where the county did want a rather extensive drainage study provided. He told them "no", and let it go for taxes.

If they will answer the phone when I call.

Let me also preface my previous post in that the Quick-2, Streamstats procedure would be my last resort after all other record sources were exhausted.

Look for any new bridges in the area - a hydraulic study was almost always done.

Contact the County and any other local authorities, specifically the County / City / State DOT Engineer and Local Flood Official first before you undertake modeling on your own.

Also, another reference source is here:

http://www.fema.gov/media-library-data/20130726-1453-20490-6341/frm_zna_265.pdf

My next job is in BFE

and I'm not looking forward to it...

Every community that participates in the NFIP is supposed to have a certified flood plain manager, per FEMA's rules. The certified flood plain manager is in many cases required to provide you with a "community determined" BFE for Zone As.

In some communities, they are on the ball and will do it for you. In other communities, all you get is silence or blank stares...

I'm missing something here.

Is she asking for you to set an elevation for the finished floor because of Flood Insurance reasons and wants to make sure she has a clean elevation certificate or is she wanting to make sure she is in compliance with local ordnances?

In Tunica County, as long as the FFE is 1' above the centerline of the nearest public road, and the health department approves the septic field, a certificate for occupancy will be issued.

Please explain the rationale

"In Tunica County, as long as the FFE is 1' above the centerline of the nearest public road, and the health department approves the septic field, a certificate for occupancy will be issued."

I have a hard time imagining how the elevation of the nearest public road could possibly have anything whatsoever to do with a structure's susceptibility to flooding. Seriously, that makes no sense in any world. Is every road crossing a flood plain raised to be at the BFE precisely, in all cases, everywhere, always?????

Please explain the rationale I'll try

>
> I have a hard time imagining how the elevation of the nearest public road could possibly have anything whatsoever to do with a structure's susceptibility to flooding. Seriously, that makes no sense in any world. Is every road crossing a flood plain raised to be at the BFE precisely, in all cases, everywhere, always?????

Not necessarily so but one must understand the topography in which one resides.
In the delta region, there may not be a 1 ft. change in elevation as far as the eye can see. land is flat or slopes of less that 1 % for miles. Roads a re usually built up with fill.

I have seen building ordinances here in LA that have ties to street or road elevations. These would be various parish or city ordinances.
I have seen 18" over the centerline of the street adjacent to the house.

In new Orleans, the Safety and Building Permits Office has an ordinance whatever is higher, 18" over the highest or lowest elev. curb or the FEMA BFE.

Yes,I have butted heads with them over the years and have refused to use their form at times.

I think that basically the mind set or wisdom is that if the road has 18" of water above the c/l then it is true disaster situation. Of course, I and others witnessed the greatest disaster in U S history here 8 years ago.

Maybe some other South LA surveyors can chime in here.

Pleas note that these ordinances were for building permits and not flood insurance. They were probably on the books before FEMA community involvement or before FEMA was created.