18 CFR 415.21 - Class II projects.
(a) A development of land, either residential or non-residential within a flood hazard area which:
(1) Includes one or more structures covering a total land area in excess of 50,000 square feet; or
(2) Contains in excess of 25 residential building lots or 25 dwelling units as part of an integrated development plan whether or not such development is included in a single application; or
(b) A development of land in the flood hazard area to mine, manufacture, process, store or dispose of materials which, if flooded, would pollute the waters of the basin or threaten damage to off-site areas, including, without limitation thereto, materials which are poisonous, radioactive, biologically undesirable or floatable.