A cheap fix might be to run some pigs in it they will sill it I had 2 cow ponds with soild rock on bottom both would go dry in summer ran pigs in them for a summer and now they've held water for 4 years now never went dry again and im in arkansas it gets dry here, iv even heard of people using highdreht limestone to sill ponds around me but I used pigs when I was done with them I ate them they were good both ways pond and eating but im no professional im just redneck lol
