Abundant precipitation, then, would have brought a dependable source of water for humans occupying the canyon and the animal and plants species there that were being exploited by the humans.
(humans; occupying; the canyon and the animal and plants species there) (the animal and plants species there; were being exploited; by the humans)
humans the animal and plants species there
occupying were being exploited
the canyon and the animal and plants species there
by the humans