The woman's body was found at around 7.20pm yesterday in the water at Diamond Harbour, Christchurch.
Her family had reported her missing around an hour earlier after she had not returned from a run, police say.
Her death is not thought to be suspicious and will be referred to the coroner.
It comes after a woman's body was found in a creek near Sisson Dr in the Christchurch suburb of Northcote about 3pm on Sunday.
Police have not considered her death to be suspicious and have also referred it to the coroner.