Purity: Disliked Places and Manners of Urination

Practical Laws of Islam as per the teaching of Ayatullah Sistani

Ruling 77

It is disapproved to urinate while standing, on hard ground, in the nests and dens of animals, and in water – particularly stagnant water.

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