It is 155 kilometres (96 mi) long, and rises inland from northern Hawkes Bay to the east of the Kaingaroa Forest.

At 8:30 am on April 6, water from the Rangitaiki River breached the College Road floodwall at Edgecumbe, causing widespread flooding across the township.

[6] A review of the flood was undertaken by a panel consisting of Sir Michael Cullen (chair), Kyle Christensen, and Charlie Price.

The river finally enters the sea at Thornton through a man made 1,500 metres (4,900 ft) long channel.

[8] Prior to the completion of the Matahina Dam annual discharge figures for suspended and bed load sediment near the river mouth were about 201,000 and 188,000 tonne respectively, Since then the Matahina dam has acted as an effective barrier to the seaward movement of sediment by the Rangitaiki River, with equivalent post-dam values have dropped to 65,000 and 10,000 tonne.

[9] This trapping of sediment has halted or substantially reduced the downstream historical rising river bed and coastal progradation of the Rangitaiki plains.

This fall of the river level encouraged further agricultural and horticultural development in this area following the end of World War I.

[7] To assist in controlling floods settlements and productive land downstream of Te Teko is protected by a system of stopbanks (also known as floodbanks).