The Messenger of Allah ﷺ forbade the sale of surplus water.
حدثنا حسن حدثنا حماد بن سلمة عن أبي الزبير
نهى رسول الله ﷺ عن بيع فضل الماء
Its isnad is sahih. It is found in Abu Dawud 3478, in the chapter on business transactions, on selling surplus water, and in Tirmidhi 1271, similarly, and in Ibn Majah 2/728, number 2477, in the chapter on pledges, and in Ibn Abu Shayba 6/254.