Mikvaos 5:2-3

Mikvaos 5:2

If a spring was made to pass over utensils or a bench, Rabbi Yehuda says that the water retains its status quo. Rabbi Yosi says that it’s like a mikvah except that one may not immerse on top of the bench (or the utensils).

Mikvaos 5:3

Regarding a spring that has many branches like a centipede, if one added drawn water to it so that it expanded in all directions, the water retains its status quo. If the spring was standing and he added drawn water so that it flowed, it’s like a mikvah in that it can purify in standing water and like a spring in that one may immerse in it regardless of its volume.