Depending on the water table in your area and the potential for flooding you could go either way. If your water removal needs are below average, you could elect to go with a low GPH rated battery backup sump pump or water powered backup. Please note that water powered systems will only work with a minimum of 20-40 PSI. They will not work if you draw your water from a well. The typical water powered system would provide between 300-1000GPH of pumping capacity. If you're in a little higher water table that the flooding potential is a bit higher, you may want to consider a battery backup system rated at between 1000-2300GPH. If the flooding potential and water table are very high, you might look at the systems rated at 2400GPM and higher. You should also check with your local municipality to make sure that they are allowed as some municipalities have outlawed them as they do waste water in a sense.