As the Heading suggests, once it is apparent that a particular facility or building floods on a fairly regular basis and you have explored the mitigation and defence measures open to you, then there are two long term options the first is Elevation:
This involves taking an exhaustive look at your inventory, processes, machinery, staff, data, in fact everything contained within the flooded building. You will then need to make decisions about what can and can’t be raised to a level that is above the expected level of a flood. You can raise machinery, suspended floors, raise power points etc. This will ensure that when the building floods vital equipment will be kept away from the water, if you decide to go down this route then the building itself should be made as resilient as possible.
See the "Additional Resilience Measures" pages in the Short Term / On Property Protection section of this document. In some cases it may be more cost effective to put elevation costs into a Capital Equipment Replacement budget, as the cost of new equipment and arrangements to have put in an elevated position may be less expensive than having to replace equipment lost to flood damage.