The river's name is eventually supposed to be corrected as part of a treaty settlement process with Rangitane and Kahungunu but as of 2021 the river's official name remains Waingawa.

[1] Its origins are close to Pukeamoamo / Mitre, the highest peak of the Tararua Range.

Once out of the ranges it flows in a straight line southeast across the Wairarapa Valley to join the Ruamahanga River at Te Whiti by Wardell's Bridge.

The Waingawa River is the southwestern boundary of the town of Masterton.

Masterton's water is piped from the Waingawa through a Masterton District Council treatment plant on the river about 10 kilometres west of the town.