The Messenger of Allah ﷺ as saying A tenth is payable on what is watered by rivers and brooks or from underground moisture and a twentieth on what is watered by draught camels. (Using translation from Abū Dāʾūd 1597)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ فِيمَا سَقَتِ الْأَنْهَارُ وَالْغَيْمُ الْعُشُورُ وَفِيمَا سَقَتِ السَّانِيَةُ نِصْفُ الْعُشُورِ