Grey River, New Zealand

The Grey River is located in the northwest of the South Island of New Zealand. It rises in Lake Christabel, one of numerous small lakes on the western side of the Southern Alps,12 kilometres southwest of the Lewis Pass, and runs westward for 120 kilometres before draining into the Tasman Sea at Greymouth.

Numerous small rivers are tributaries of the Grey, and several of them also drain lakes. Notable among these are the Ahaura River and the Arnold River, the latter of which is the outflow of Lake Brunner, the largest lake of the northwest South Island. A small hydroelectric station is located on the river 25 kilometres upstream from the mouth of the river.

The Grey River's mouth is protected by a large sandbar which is a notorious danger to shipping.

The river was named by explorer Thomas Brunner in honour of New Zealand politician Sir George Grey. The Maori name for the river is "Mawhera".