An elderly man is expected to appear in the Lephalale Magistrates Court on Thursday for shooting at a couple who was fishing along the Mogol River.
The incident happened at 2 pm on Tuesday afternoon.
Police spokesperson Lieutenant Colonel Mamphaswa Seabi says the 77-year-old man said he thought he was shooting at a hippopotamus.
She says a 38-year-old woman sustained a gunshot wound while her partner managed to hide and contact emergency services.
Police seized two rifles, a revolver, a pistol and two airguns during the arrest.
A case of attempted murder is under investigation.