Water Supply Act Article 34

Except under the following circumstances, a water supply enterprise shall not supply water beyond its designated area:1. Having the approval of the authority-in-charge to supply water to another water supply enterprise.2. Upon the order of the authority-in-charge to supply water to national defense industry.3. Having the approval of the authority-in-charge to supply water to residents who live in areas without tap water and request water supply.4. When another water supply enterprise in adjacent areas stops water supply due to a disaster or other emergency events and can not repair the equipments in time, that urgent and temporary water supply is necessary.
中文原文 自來水法第34條
自來水事業除有左列情形之一者外,不得供水於其供水區域以外之地區:
一、經主管機關核准供水與另一自來水事業者。
二、經主管機關特別指定供水與國防事業者。
三、無自來水地方居民申請供水,經主管機關核准供水者。
四、因災變或其他緊急事故,鄰近自來水事業停止供水,一時不及修復,必須緊急暫時供水者。

English translation for reference only; the Chinese text prevails. Not legal advice.