Police said they were called to reports of four people in trouble in the water there about 1.30pm.
They were pulled from the water near the Pakiri Beach Holiday Park on Pakiri River Rd but one died at the scene.
A St John Ambulance spokesman said one of the people, a man, was flown to North Shore Hospital in a moderate condition via rescue helicopter.
He said two children were treated by ambulance staff at the scene and did not require transfer to hospital. It's unclear why the group needed rescuing.
A worker at the holiday park, which borders remote Pakiri Beach, north of Omaha, did not want to comment.
A social media post says a rahui has been put in place for three days. It started at 3pm today and will continue until 3pm Tuesday, the post says.