Livewell 101: Water enters the boat through the "inlet" in the transom. A hose connects that fitting to the pump. Another hose connects the outlet of the pump to the spray bar in the live well. A break in the system anywhere along the line will flood the hull. Either the pump has a broken housing due to freezing (if you live in that part of the country) or it simply broke, or either the inlet or outlet lines are cracked or broken. In any case, repairs must be made. If you don't intend ot use the live well cap it off at the transom as was suggested.