We just had a huge rainstorm and I had to drop "two" 1/2 hp sump pumps into the sumphole (16" wide x 23" deep) in my basement. The two pumps were just barely keeping up with the water inflow. The largest sump pump I can find at the store pumps 5100 GPH at 0" (4100 GPH at 10") and it is a 3/4 HP pump. I noticed 1/2 HP sewage pumps with a 2" discharge that pumps 9000 GPH at 0'. In an heavy water emergency, could I use a pump this strong and run it into a 1 1/2 discharge? I would only use it in an emergency. Thanks for your help.