Rules for Yatis from Kalpasutra of Bhadrabahu

During the Paggusan monks or nuns are allowed to go and return, for the sake of collecting alms, not farther than a Yogana, and a Krosa (from their lodgings). (10) If there is (in their way) an always flowing river which always contains water, they are not allowed to travel for a Yogana and a Krosa. (11) But if the river is like the Eravati near Kunala, such that it can be crossed by putting one foot in the water and keeping the other in the air, there it is allowed to travel for a Yogana and a Krosa. (12) But where that is impossible, it is not allowed to travel for a Yogana and a Krosa