Toyota has corrected ground clearance to 225mm for fortuner. Very similar to Prado. 279mm was misleading info, and head to head, it is similar to all other SUVs including Prado (220mm), Pajero (218mm) etc, plus minus few mm depending on individual vehicle design.
In fact, some websites quote the ground clearance at 220mm for fortuner too.
The wading depth for Fortuner is identical to Prado and Pajero, i.e 700mm.
http://www.caradvice.com.au/408536/toyota-fortuner-ground-clearance-downgraded-from-279mm-to-225mm/
Google will shed more light on the matter.