In fact, revolving the supply on a three-year cycle not only spread wealth more evenly among the farmers. By rotating crops, it also improved soil quality. Only four years after the waterworks opened, Tainan Prefecture (today's Yunnan, Chiayi and Tainan Counties) became the new granary of Taiwan, with annual production of rice, sugar cane and other crops increasing from 20,000 tons to 80,000.
事實上，3 年輪灌的制度不但讓農民雨露均霑，還因反覆耕作不同作物，改良了貧瘠土壤，嘉南大圳供水後僅僅 4 年，台南廳（今天的雲嘉南地區）便躍居台灣新穀倉，稻米及甘蔗等產量從每年二萬多噸提升到八萬多噸。