Anyone out there ever have a call to an elevation certificate on the main building of a municipal water plant?
Lowest point of conceivable damage is the floor of the filters, I guess. The common building floor and lowest level of equipment could be as much as 10 feet or more higher than that. Are the filtration tanks basements? Or, since those tanks are full of water which would resist any saturated soil pressure outside the wall, does this let you not worry about that level. Unlike a swimming pool, these areas should always be full of water.
Comments are to be welcomed.
It would be interesting to know why the cert is needed. Are they trying to get flood insurance on the plant (assuming that's possible)? Or are they perhaps trying to show that it conforms to the local floodplain ordinance?
The tanks would probably resist flooding, as you say. But there's no reason you should be the one to figure that out and take the responsibility for it. This is not a multiple-choice situation like those in the flood map diagrams. What's needed is an engineer who will identify the lowest vulnerable structure(s), explain that finding, and put his/her name on it. Then you can shoot them with an easy mind.
Only the building is covered by flood insurance. Outside improvements, like swimming pools, are not covered. I'd think a filter tank would be comparable to a swimming pool and would not get any coverage.
I'd talk with the client, and direct him/her to discuss this with the insurance agent, to determine what FEMA will and won't cover. I'd also put notes in the comment section stating that the elevation certificate only supplies data about the building, and not the outside sewage treatment equipment. I might even attach an Aerial photo with the building highlighted, and a note that says "This elevation certificates applies to this building only".
I did one at a sewer treatment plant after a flood. Were talking big fines.
Take lots of pictures with small paint marks to show FEMA the shots. It should not have flooded.
