Cut a hole 30-inch by 30-inch in the basement floor. Make the hole 30 inches deep and place 5 inches of stones at the bottom. The stones should be the size of an egg. Center an 18-inch by 18-inch flue liner on the stone. The top of the flue liner should be 1 inch below the existing concrete floor.
Insert egg-sized stones around the flue liner to fill the space. Using the top of the flue liner as a form, patch the concrete with concrete mix. Slope the patch down toward the flue liner to allow the sump to handle large amounts of water.
Install a submersible sump pump with high capacity. Use the correct diameter pipe and include a foot valve as a pump outlet that runs straight up to the ceiling. Attach a horizontal run with a slight drop to the outside through a band joist. Place a concrete block directly under the discharge pipe to prevent erosion.