So I have a lady whose house is along a lake and she is wanting to add an addition to her house.?ÿ Looking at the FEMA map its hard to see here house but I suspect the line of a flood zone A is a blob of ink that lies on top of her house.?ÿ To borrow money they are requiring her to get flood insurance.
There have been a couple of LOMA's done for houses on the same lake and they removed them from the flood zone.?ÿ I can see the elevations of the nearest grade on the LOMA approval form that I can view on line but there is no BFE listed.?ÿ One of the houses is about 1600 feet from the house I would be working for.?ÿ My clients house is closer to the dam.?ÿ The dam was most likely built in the 1960's and I'm an unsure about getting data for it.
So would FEMA take a LOMA for a house and approve it if it the same elevation or above the elevation of the house 1600 feet away where the LOMA was approved?
If you can obtain any data on the spillway of the dam and the 100yr flood elevation that was designed for I am sure that would support the case for a LOMA I would also include the neighboring LOMA as another supporting document. Also check the fis report for elevations.
I believe it's all about elevation. If the grade of the existing ground where the addition is to be placed is above the 100 year flood elevation, you should be good. I'd get the LOMA of the abutting home. If they are upstream, you have a good argument.
I'll add: Don't count out design data on the dam. Or, perhaps a hydraulic analysis completed more recently.
Georgia and North Carolina (and probably many more states) have dam inventorying programs required by emergency management protocols. Typically there are vertical storage parameters but, gross drainage area can tip a dam 'in'. It's a 'life/ property' protection/ prevention effort.
So, try your state agency to see if it's been inventoried. If so, they may be able to help with flood elevations.
In the state of Washington the DNR keeps an inventory of the dams and I see the Iowa DNR does likewise. Our state requires a survey (vertical) each time the dam is breached so you may check?ÿ those records. I saw you're also licensed in Illinois so you can check that state DNR if they have one. Another place to check is the USACE to see if they have records on the dam or pool behind it and have established an elevation of the pool.
I called another surveyor that I know who works on the same area and he had a letter that listed a BFE from a recent engineering study on the lake.?ÿ So I should be set.?ÿ Thanks for all the answers.?ÿ