shiu demonstrates his physics with the ikea ps fejo self watering plant pot. "because the pot is self watering, meaning there is a water reservoir in the bottom, there is no drain hole. with a few days of non stop rain, the pot of soil turned into slush. what to do? physics to the rescue. i bought four feet of aquarium pvc flexible tubing/air hose from a pet store. filling it with water first (or you can suck the water into it after insertion), i dug down into the mush/soil and inserted the tube under the top plate of the water reservoir. as long as you keep the outside end of the tube below the pot, gravity from the outside end of the tube will draw the water out."
and there you have it - anti-flood measures. read more here.
this other pot hack involves turning trash cans into planters.