Chapter on the Ruling Regarding Reserved Areas
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 1|Chapter 42
وَ رَوَى عُقْبَةُ بْنُ خَالِدٍ عَنْ أَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ: فِي رَجُلٍ أَتَى جَبَلاً فَشَقَّ مِنْهُ قَنَاةً جَرَى مَاؤُهَا سَنَةً ثُمَّ إِنَّ رَجُلاً أَتَى ذَلِكَ اَلْجَبَلَ فَشَقَّ مِنْهُ قَنَاةً أُخْرَى فَذَهَبَتْ قَنَاةُ اَلْآخَرِ بِمَاءِ قَنَاةِ اَلْأَوَّلِ قَالَ "يُقَايَسَانِ بِحَقَائِبِ اَلْبِئْرِ لَيْلَةً لَيْلَةً فَيُنْظَرُ أَيَّتُهَا أَضَرَّتْ بِصَاحِبَتِهَا فَإِنْ كَانَتِ اَلْأَخِيرَةُ أَضَرَّتْ بِالْأُولَى فَلْيَتَعَوَّرْ وَ قَضَى رَسُولُ اَللَّهِ صَلَّى اَللَّهُ عَلَيْهِ وَ آلِهِ بِذَلِكَ وَ قَالَ "إِنْ كَانَتِ اَلْأُولَى أَخَذَتْ مَاءَ اَلْأَخِيرَةِ لَمْ يَكُنْ لِصَاحِبِ اَلْأَخِيرَةِ عَلَى اَلْأُولَى سَبِيلٌ" ".
Narrated by Uqbah ibn Khalid from Abu Abdullah عليه السلام: Regarding a man who dug a water channel from a mountain, and its water flowed for a year. Then another man came to the same mountain and dug another channel, but the second channel diverted the water of the first channel. Imam عليه السلام said: "They should measure the water flow using the buckets of the well, alternating night by night, to determine which channel has caused harm to the other. If the later channel has harmed the earlier one, then it should be removed." And the Messenger of Allah سبحانه وتعالى (peace be upon him and his family) judged similarly, saying: "If the first channel has taken the water of the second channel, then the owner of the second channel has no claim over the first."
- Ṣaḥīḥ al-Faqīh, p. 196