Would a Canopy over Electrical Panels in a WWT Facility qualify for a Risk Category III (The Risk Category assigned to all structures, Seismic Design Category C, Site Class E).
Canopies are pretty small loads, so I'd likely just be conservative if I were doing the design.
If it's an item of contention, though, I'd send a formal question to the owner asking for confirmation. Utilities like this will often have a seismic design strategy if they're in a reasonably significant seismic zone.