Our basement is quite dry most of the time, with low humidity. However, when there is a severe rainfall, the water table rises such that our sump pump (which is sealed, due to radon mitigation), cannot keep up; the pump is on constantly, yet we get 2-3 inches of water in the basement. This happens once every other year. It's clear that the sump pump is inadequate during these times of stree.
My question: 1. Do I get a more powerful pump? 2. Do I install a second sump pump? If so, do I need to dig another sump, or just hook up a second pump to the same discharge drain as the first pump, using check valves (hooking up the second pump so that it activates only when the water level rises close to flood stage)?.