I have a potential client who is in the process of buying a house which happens to be mapped 1/2 in Zone X and 1/2 in Zone A. As there are no published Base Flood Elevations on the FIRM, just Zone X and Zone A area's, ROUGHLY how much work would be involved to do a LOMR where there are no published BFE's? Another surveyor has already done the Elevation certificate for the seller.
Honestly, I've only ever done elevation certificates and I'm a might leery of quoting a hard price/timeframe.
The hydrologic study required probably falls outside of the intent of the licensing law for surveyors in your State. See the thread below on a similar topic for related comments.
Yes, a Civil will need to do a hydro/hydraulic study with HECRAS or similar program.
Not knowing anything about the site and just shooting from the hip, I would guess it will be between $1500-3500 for that work (assuming the survey sections are provided to them).
I've been involved in quite a few of these in my area since the new FIRMS came out in 2009. If they want insurance, Section E of the elevation certificate should be filled out in addition to Section C. Section E lists the heights of the LAG and HAG in reference to natural grade (before construction) and also shows if the lowest floor was constructed the correct height above the natural HAG. Unless you have a copy of the site plan, natural grade will have to be calculated by interpolation.
If they want to try and get removed from the flood plain you will have to establish the LAG for the home and then see if you can find a BFE, which I don't usually find unless a LOMA has granted for an adjoining property. If a BFE isn't found shoot a couple quick cross sections on the flooding source and prepare a sketch showing the house, LAG and cross sections along with any other pertinent spot elevations (nothing elaborate) and upload it via the new LOMC online application. As of the last couple years, more often than not FEMA has calculated a BFE for me.
Be sure to let the client know ahead of time that there is no guarantee that the structure will get removed and that it is up to FEMA.
Thanks, the house was built in 1984 on knoll. Main floor roughly 15' above the nearest Creek 200 yards away. Unfortunately, they daylighted the basement so the lowest floor is only about 6 ft above the creek's normal High water.
In a Zone A, the natural HAG (pre construction) is used as the BFE (unless you have one established) to rate insurance. If the lowest floor is less than 2 feet below the natural HAG the premium may not be that bad, but if it's 2 feet or more it's a "submit to rate" and will most likely be extremely high.
I would start by determining if the lowest floor is below the natural HAG and go from there. If it is, I would advise the client to have a cross section shot and submit as a LOMC. They are free even if FEMA calculates a BFE for you, so the only cost will be for your services.
Wait, what? You can use a base flood elevation on a nearby LOMA for your elevation certificate? The LOMA guidelines state that I can only do a LOMA on a single parcel, I never thought about using that established BFE for adjacent parcels, as it is a calculated adjustment, rather than an established BFE.
FEMA never gave you any grief about this?
Makes perfect sense to me. If it's 847.6 a couple hundred feet away based on a previous LOMA and I'm hitting actual elevations a few tenths to a few feet higher than that I wouldn't hesitate for a second to go with 847.6. If FEMA wants to do a recalculate and arrive at a slightly different value, that is their choice, but, if it is significantly different for some reason I would definitely challenge them for why their reasoning varied so much.
