The disclosed liquid storage tank has a concrete tower section. A steel tank shell above the tower section encompasses a tank volume that has a capacity of at least 100,000 U.S. gallons. A concrete ringbeam at the top of the tower section surrounds an internal area between the ringbeam and an access tube that extends from within the tank volume into an interior of the tower section. The ringbeam has an integral upper wall above a ring-shaped, upwardly-facing supporting face that is at least about 4″ inches wide and resists downward forces. A series of laterally adjacent concrete dome segments creates a dome that has a vaulted upper surface and essentially covers the internal area. Each of the dome segments has an outer end that sits on the supporting face of the ringbeam, and an inner end that is positioned above the outer end. Lateral sides on each segment define a segment angle, and the sum of the segment angles of the adjacent segments is less than 360 degrees. Fill sections extend between adjacent dome segments. A pourback creates a continuous surface from the top of the upper wall on the ringbeam to a raised portion of the dome segments. A steel liner covers the dome. The liner has a vaulted upper surface and is connected to the tank shell. In building the tank, precast dome segments can be temporarily supported, with the support being removed after all the segments are placed.