I am at the beginning of my Terrace dressup project. Bought a few IKEA PS FEJÖ self watering plant pot. The color scheme works nicely with the rest of the terrace. Planted our Clementine Mandarin orange tree in one of them. Then came the heavy rain. Because the pot is self watering, meaning there is a water reservior 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 reservior. 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. You can see it draining here:
About 30 minutes later, the soil in the pot is (almost) back to just very very wet. I will keep the hose there now and next time it gets flooded, a little (careful) sucking and I can siphon out water again.