950 Imp Gallon Black Hippo Leg Water Tank Low Profile Tanks for Hauling & Storage. Find the right solution for your job our horizontal tanks over 950 gallons are suitable for storage and transport applications. Need a tank to fit under the cottage or the deck? The deep ribbing provides extra strength and helps reduce sloshing in transport. 950 gallon Hippo leg tank that has been designed to be less than the width of a standard trailer ensuring this tank will fit. See our website about our other size and application water tanks! Our Norwesco tanks are made out of rotationally molded linear, high-density polyethylene resin that provides outstanding environmental stress crack resistance. The resin is UV stabilized.