I suspect, without being familiar with your particular brand (I'm in the U.S.), that the "excess water" comes from one of two causes. One, simply having humid summer weather conditions that causes condensation on the inside of the fridge every time you open the door. Not much you can do about that.
Additionally, most drip trays as you describe are overflow from the automatic defrost portion of the freezer (if you have one). The plates that collect the ice (primarily from again, condensation)are heated intermittently to melt the ice collected, which then drips down to the tray. Usually, such moisture doesn't overflow but, if coupled with summer time condensation it could happen.
Long way of saying your probably stuck with the situation until the weather gets colder and humidity level decrease. Either that or don't open the door unnecessarily… Best of luck!