How easy is it to drain the water from the AGLucky Ice Maker? Does it have a built-in drainage system, and how effective is it?

Yes. There is a drainage plug on the bottom right of the machine. The plug is made from silicone and is attached to a harder plastic tether which hooks out of the way up against the body when draining water. Simply rest your machine partly over the edge of your kitchen sink, and pull the plug out using the tether. You will need to tilt the machine a little to remove all the water. Afterwards you should dry with a cloth, and if you're going to store it away, leave the machine out for a couple of hours to dry out more completely.