The Wharekōpae River is located in the Gisborne region of New Zealand's North Island. Rising on the slopes of Maungatapere, a 1,050-metre peak at the northeastern end of the Huiarau Range, the river flows generally eastward before joining the Waikohu River near the settlement of Waikohu, west of Te Karaka. The Waikohu is itself a tributary of the Waipaoa River, placing the Wharekōpae within a larger catchment system that drains toward the Poverty Bay Flats.

A flow monitoring station is maintained at Rangimoe, and the river is used for kayaking, packrafting, and rafting, among other activities. Flow rate data, water level readings, and rainfall forecasts for the Rangimoe station are available through online monitoring services, which paddlers can consult when planning trips.

A notable feature along the river is the Rere Rock Slide, a smooth natural rock formation approximately 60 metres long, along with the adjacent Rere Falls. Both are located at Rere and represent significant points of interest along the river corridor. Trout have been introduced to the Wharekōpae and are present in the river, though they are not known to migrate. The river's Māori name translates to "house with a side door," reflecting an unusual feature of traditional Māori dwellings.