This happened to me this August in France, the muddy water just burst through over the footpath in front of me, about 12 - 15' wide and about knee height. Very scary at the time and no alternative route, other than to go back. I took my boots and socks off, hung them around my neck and then waded across wearing my flip flops. The most important tool was my walking sticks, they gauged the water depth, helped me to locate any deep underwater holes (there were none) and helped me to steady myself against the strong water flow. I could feel the earth and stones moving under me.
A couple of years ago in the Lakes, whilst trying to leap from rock to rock without walking sticks aid, I slipped and fell in up to my knees, something I never want to repeat. For me, nothing worse than wet feet, wet socks and wet boots, especially when it is raining hard at the time anyway! In addition to normal socks I also carry a pair of trainer inserts with me, it doesn't fully solve the problem but with these and a pair of dry socks it certainly helps when errors are made.