29 gallon fuge

I finished my 29 gallon fuge for my 50g display tank. I decided to do the baffle set up. There are acrylic baffles (6) to help the water flow. I will have a mag 12 to pump the water to the top tank. Im afraid that I might of made the baffles too high. If the power goes off in my house, the water from the top tank will drain to the drain hole, which is more whater than the fuge can handle. I will think of something