I don´t think there is any problem with the water damaging the electrical components under typical situations. The real danger is the same for all vehicles and that is hydrodynamic forces sweeping the vehicle off the road or the lack of visibility hiding a dangerous condition under the water.
Here´s what I do, if the road is flooded and there is an alternate route, take the alternate. If you have no choice but to press ahead, test the crossing by first walking it. If the water is deeper than your hub or if it feels like its moving fast enough to sweep you off your feet, turn around and find a safe place to wait it out. Its amazing how a few inches of water can sweep even a 6,000 pound truck off the road.