Nelson Historical Society Journal, Volume 2, Issue 1, 1966
In the 1842 map it was spelt Tipahi, and it has also been Tepahi. I cannot trace the origin of this name.
The nearest I can find in local history is the name of a Maori Te Pehi or Tippahu, who visited England in the 1820's. His daughter married Captain Blenkinsop, a whaler at Cloudy Bay, in 1831. The Captain is said to have bought the Wairau from the Maoris for a cannon, and had a deed to prove it. His widow sold the rights in this deed to Colonel Wakefield in 1839 and the New Zealand Company's rights to the land in the Wairau was partly based on this.