Purity: Wudu with Water from Streams

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 270:

There is no problem in performing wuḍūʾ with water from streams that rational people would consider permissible to use without the owner’s consent – irrespective of whether the owner is an adult or a child – even if one does not know that the owner consents to it. In fact, it is permitted to use a stream’s water even if the owner forbids performing wuḍūʾ with it, or if one knows that the owner does not consent, or if the owner is a minor (ṣaghīr) or insane.

-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)