It was narrated that Tha'labah bin Abu Malik said:

“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.

حَدَّثَنَا إِبْرَاهِيمُ بْنُ الْمُنْذِرِ الْحِزَامِيُّ، حَدَّثَنَا زَكَرِيَّا بْنُ مَنْظُورِ بْنِ ثَعْلَبَةَ بْنِ أَبِي مَالِكٍ، حَدَّثَنِي مُحَمَّدُ بْنُ عُقْبَةَ بْنِ أَبِي مَالِكٍ، عَنْ عَمِّهِ، ثَعْلَبَةَ بْنِ أَبِي مَالِكٍ قَالَ قَضَى رَسُولُ اللَّهِ صلى الله عليه وسلم فِي سَيْلِ مَهْزُورٍ الأَعْلَى فَوْقَ الأَسْفَلِ يَسْقِي الأَعْلَى إِلَى الْكَعْبَيْنِ ثُمَّ يُرْسِلُ إِلَى مَنْ هُوَ أَسْفَلُ مِنْهُ ‏.‏