Sunan Ibn Majah Book 16, Hadith 47
the Messenger of Allah (ﷺ) ruled concerning the stream of Mahzur that the water should be retained until it reached the ankles, then released.
“The Messenger of Allah (ﷺ) ruled concerning the stream of Mahzur that the higher ground took precedence over the lower, so the higher ground should be irrigated until the water reached the ankles, then it should be released to those who were lower.
the Messenger of Allah (ﷺ) ruled concerning the irrigation of palm trees from streams, that the higher ground should be irrigated before the lower, and that the water should be allowed to reach the ankles, then released to flow the nearest lower ground, and so on, until all the fields were watered or until the water ran out.