Musnad Ahmad 30:206

Sufyan narrated to us, from Abu al-Zinad, from al-A’raj, from Abu Hurairah, attributing it to the Prophet, may Allah bless him and grant him peace: "The surplus of water should not be withheld, so that the pasture may be withheld by it." Sufyan said: "There is pasture around your well, so you withhold the surplus of your water from them, and they are prevented from grazing."