But I can't imagine why anyone would want to risk a Rohloff and in my case also risking a dynohub on a stream crossing when it would only take a few minutes first to assess how deep it is.
I ride on narrow lanes, often only one car wide, with the ditch or even a stream right next to the edge of the tarmac. I do it for peace of mind, to avoid speeding trucks and cars on roads quite unsuitable for bicyclists. (The disciples of John "Take the lane" Forester might note that a police superintendent who used to ride with me was killed by a truck while cycling on a road onto which I refused to accompany him. To my mind, that's all the evidence -- and more -- required to label a road as dangerous.) But in the harvest season even my small lanes have huge self-powered harvesters dashing from field to field to get the harvest in and hay-bales rolled before the rain falls again. These machines, with 4ft long rows of spikes out the front, overhang the ditches and are capable of at least 35mph.
https://farmingvideos.co.uk/video/first-kind-introducing-zr5-self-propelled-baler-vermeer-agriculture-equipment/The rest of the year I expect the people on these lanes to wait patiently behind my bike until there's a driveway or an even smaller side-lane for me to pull into to let them by. But in the harvest season, to reward them for their patience, I ride in the rain when the harvesters stop because a wet harvest rots, or if I get caught out in a lane when the sun shines and they're rushing for the next field, jump into the ditch and hold my bike above my head. Or I used to; I'm not that strong any more. So I just stay off the lanes, or stop by the contractor's van parked at crossroads where they can stop and redirect motor car traffic, and normally have a navigator/bookkeeper in place too, and ask in which direction they're moving so I can ride in the opposite direction.
Here it's generally pretty obvious how deep water is. At fords water would reach the hubs on a bicycle with 26in and bigger wheels only in floods, themselves pretty obvious. I'd be more worried about shallower water on a sunken area of tarmac being hit at speed and spraying with some force to a much higher level than a bicycle hub. We have just such a place on a road we ride a few times a year. (We know all these sunken places on blacktop roads because in the black ice season they can put you down.) Floods or heavy rain leaves this area with three or four inches of standing water and if we hit it with even modest speed it sprays everywhere, enough volume and force of water to soak you through unless you're wearing wetproofs, which we don't normally except as windbreakers in the cold season. It's such a nuisance that in the appropriate seasons we give that road a miss. Of course, on a tour the cyclist will not know that such an innocuous-appearing piece of road can cause an hour of nuisance in changing the oil out of schedule, or the irritation of being soaked on an otherwise sunny day.
I read Martin's and Dan's examples above and am grateful to live in a place so long civilized that one can know all the places where water gathers to expense- or nuisance-making levels. Heh-heh. Actually, we have a riverside path on one side of the river that right here in town is no longer bikeable because dredging work on the river left it with a gradually deepening dip that would be over hub height in the middle when the river rises over it; no great loss as in the work the path also lost its exit, so goes nowhere, whereas the ride on the opposite bank of the river was widened and improved and led through a park and playground (with concrete bicycle trick ramps!) to provide a shortcut out of town.
