Immediately beyond Long Reef, the rocky point at the southern end, is the mouth of the Hollyford River and Martins Bay.

The Awarua River enters the bay at the northern end of the beach.

The mouth of the Awarua River is the western end of the boundary between the West Coast Regional Council area and the Southland Regional Council area.

Three Mile Beach, the Awarua River and Waiuna Lagoon are within the boundary of Southland region.

Awarua Point is within the boundary of the West Coast region.