Nope they do not. They are clever little buggers..have a wonderful home underground...clever engineering prevent this from happening.

At one level, obviously not: since it rains frequently, and moles are not extinct, they obviously have some way of handling it. I have notices, on the occasions that I have had moles in my garden, that in winter their tunnels are much shallower than in summer - only just below the ground. My garden gets quite soggy, so I think that they are digging their tunnels just above the water level. Also, since they can dig like the clappers, I would imagine that if the water level started rising, they would dig straight up and escape. Mind you, I would expect that a few moles drowned in the UK floods this summer. But now the floods have receded, they will probably be back. Perhaps they avoid flood plains.

No, as they make their dens with entrances underground that angel upwards so they may get blocked in there but they don't drown. Plus they make special draining tunnels to make the water flow away from their sleeping dens.

Sometimes, but usually not: 1) "The girl, carrying the bouquet of flowering weeds she had picked, neared the tombstone. As she drew closer, the sky filled with boiling black clouds and shut out the sun. A clap of thunder startled her and when a torrent of rain burst forth she quickly turned and ran looking for shelter. Lightning speared across the sky and more thunder crashed. Rain streamed from Digger McDirt's cap. He turned to Shag and said, "What a miserable end to an even more miserable day. Let's get out of this storm." They scurried through the soggy grass and puddles of water. Shag in his hurry, and usual nervous excitement, tripped and fell in the mud. He gathered himself together, shook off the mud and said to Digger, "Well, that's par for the course on a day like today." "We don't live on the golf course anymore, Shag. Get a new saying!" Digger replied, shaking his head. The moles disappeared into their underground home. Digger asked his cousin Spade McDirt, Tom Tellitall, and Shag to gather in the meeting room after drying off. They needed to plan what to do next about the stolen necklace and coins." Source: http://www.pegtales.homeip.net/digger4.html 2) "Beneath the soil, in a long wandering tunnel, a mole pushed its way with heavy, scooplike front feet, twisting its body so first the roof and then the sides of the burrow were packed tight. Then, turning a slow somersault in the narrow space, the mole retraced its path, stopping now and then to shake moisture from its fine, dense fur. Its deeper living quarters were completely inundated, and even the surface foraging tunnels at times were filled with water through which the mole had to pass quickly, its fur glistening like silver with trapped air. Blind though it was, it was hunting, for its other senses were keen. Normally it would hunt most actively in the daytime, when insect activity was greatest, but tonight as the soil filled with water, earthworms, grubs, millipedes, and centipedes began heading for the surface where there was a greater supply of oxygen. Their progress frequently was terminated by the mole as it scrabbled excitedly in search of victims which penetrated its burrow. Upon finding a beetle, it pressed the insect against the wall of the tunnel with one of its front feet, while it bit off the head and then began to devour the whole insect. Later, it came across a large earthworm which it dextrously manipulated until, starting at the front end, it consumed the whole length of the worm with sharp conical teeth and jaws working furiously." Source: http://www.mountainman.com.au/infriver.htm 3) "Coyote dreamed that water would soon cover the world, but nobody believed him. It rained, and the water started rising. The people climbed trees because there were no mountains to escape to. Coyote and a number of people escaped on a log. With the help of Mole, Coyote created mountains; then he created people for the new world." Source: http://www.crystalinks.com/floodstories4.html 4) "“You mean you dug your way to the High Place?” asked Giraffe, blinking her long eyelashes in disbelief. “I told you that the rains would cause us no problems,” said Mole-Rat." Source: "Mole-Rat Keeps His Feet Dry" http://www.eed.state.ak.us/tls/assessment/sba/2006PracticeTests/4P01RPT.pdf 5) "Home remedies such as placing hair, broken glass, mothballs, motor oil, etc. in tunnels, liming the soil, and flooding are rarely effective although such actions may repel the moles for a short time. Flooding eastern mole tunnels in a dry soil using hundreds of gallons of water may drown the mole or may force it to the surface where it can be killed. Attempting to drown moles in a sand to loam soil is usually futile. Where starnosed moles are involved, the flooding of their tunnels is beneficial to the moles, since they prefer moist soils. Chewing gum, Alka-Seltzer, etc. are not effective. " Source: http://web1.msue.msu.edu/imp/modwl/11209807.html

I hope not.