Human made dam in the Chauvet cave

Paleolithic men built a wall about 5 meters long behind which water accumulated naturally. What did Prehistorics do with this water? Did they prepare dyes for painting or did they see them as a more symbolic function? This question is not settled. This dam consists of two slabs (respectively 2 m and 1.5 m thick and 25 cm thick), moved and planted subvertically in the soft soil and probably extended by two other slabs partially hidden by concretion. The clogging of the joints between the four slabs could have been made with clay collected nearby in a small quarry in which fingerprints are very numerous and always visible.