Enforcement Rules for Water Act Article 27

The order of acceptance of application for water right registration as provided in Article 29 of the Act or application for temporary right of water usage as provided in Article 44 of the Act shall be determined by the actual date (year, month, day, hour) of receipt by the authority-in-charge; for applications submitted by registered mail, the date of receipt shall be the date as postmarked.
中文原文 水利法施行細則第27條
主管機關受理本法第二十九條水權或本法第四十四條臨時用水登記之申請,其申請之先後順序,按主管機關實際收受登記申請書之年、月、日、時定之。
但以掛號郵寄方式提出申請者,以交郵當日之郵戳為準。

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