Because Taiwan has uneven rainfall over the course of a year, with a wet season and a dry season, government agencies with responsibility for agriculture have long mandated rationing measures during dry spells, including rotating irrigation water by district or enforcing an on-off day schedule for the supply of irrigation water. The government has also been pushing the use of water conservation technology for dry-field agriculture (see "Master Managers of Water").
由於台灣降雨豐枯不均，農政單位早已發展出旱季缺水期間的因應措施，包括分區輪流灌溉、間歇灌溉，以及旱田的節水灌溉技術等（見「老管家，新思惟──嘉南農田水利會」一文），才能在旱季節省出相當比例的農業用水，調撥給民生、工業使用。