DOC have released the Operational Plan for the St James Conservation Area. It recognised the value of the Upper Waiau, noting
Below the point where it is joined by the Ada River, the upper Waiau River is one of the best rivers for rafting and kayaking in the eastern South Island.
Kayaking access via 4WD over Maling Pass is confirmed (p42):
Provide 4WD motorised vehicle access as far as the Waiau River via Maling Pass and Edwards valley for rafting/kayaking and canoeing. Thanks go to Hugh Canard and Whitewater Canoe Club for leading negotiations with DOC and demonstrating kayaker access on a successful Upper Waiau trip on Labour Weekend 2009. Helicopter access is being determined via other processes.