Although Tuhoe and Kahungunu were hostile to one another, Pourangahua maintained good relations with both as a taha rua ("friend to both sides").
This blocked the river and caused the land behind the hills to flood, creating Lake Papuni.
Pourangahua rowed over in his canoe and performed magic spells which forced the two hills apart, creating the lake's outlet.
J. H. Mitchell suggested that this story preserves memory of an earthquake that caused a landslip to block the river.
The wharenui of Erepēti marae, which is located in Ruakituri and belongs to Ngāti Hingānga, is named Pourangahua after this ancestor.