The Office of the Judge (Kitab Al-Aqdiyah)
Dawud :: Book 24 : Hadith 3632
Narrated Abdullah ibn Amr ibn al-'As:
The Apostle of Allah (peace_be_upon_him) decided regarding the stream al-Mahzur that its water should be held back till it reached the ankles, and that the upper waters should then be allowed to flow to the lower.