The wastewater treatment plant described and illustrated features the first permanently-installed Claricone helical flow reactor clafifiers. Three of these hydraulically-driven units operate in conjunction with a gravity flow treatment system, which combines a grit and oil removal structure, a flow and temperature stabilization lagoon, and chemical feed system. Power consumption is lessened with few mechanical moving parts. The benefit of the treatment plant is the conservation of an average 13,247 cu. m/day water which is returned to the municipal water supply.