A new concept of power plant heat-sink system is presented which employs the combination of a conventional wet-tower and a conventional dry-tower. The purpose of this cooling system is to reduce wet cooling-tower makeup-water requirements in water-short areas. The dry tower operates all year around while the wet-peaking tower is used only above certain ambient dry-bulb temperatures. The two cooling circuits serve separate sections of a conventional, surface-type, steam condenser. Thermal performance analysis is presented for various combinations of cooling systems ranging from 100 percent wet to 100 percent dry. Annual makeup-water requirements are calculated for various sizes of towers located in 18 selected cities of the U.S.A. ranging from north to south and east to west.