What is a LOMA?
The surveying is identical for both. A flood certificate would be done for a permitting authority, often city government but occasionally the county.
A LOMA is a Letter of Map Amendment, done most often because a lender or insurer is requiring the owner to either get flood insurance or file a LOMA showing that the improvements are not in the flood zone. FEMA has prepared maps (called panels; they just gotta be different) of floodways. Flood zones are shaded areas on the panel, with cross-sections showing the 100-year flood level. The LOMA is a document of several pages, giving elevations of the benchmark, 100-year flood level, elevation at building at lowest point, and the various floors. Close attention is paid to building openings and even joists in crawl spaces.
Are You Going to Take My Picture?
It is amazing how often passers-by assume that a total station instrument is a camera. It is not a camera, but rather more of a laser telescope. The graduated dials for measuring horizontal and vertical degrees, found on a transit, have been replaced by digitization. The steel tape has been replaced by a laser. We sight the target (a prism), hit a button, and data is produced: what are called x-y-z coordinates. The x represents an easting, the y a northing, and the z an elevation. That’s three-dimensional data which can be uploaded into CADD to produce a three-dimensional drawing.
Steven Higley, Professional Land Surveyor based in Western North Carolina.