It would be the first large generation project in Hawke's Bay since the Waikaremoana Hydro Scheme, established in 1929.
Esk Hydro had a Run Of River design, different from the conventional hydro-electric stations because it did not have a sizeable reservoir.
Instead water was diverted into pipes leading to downstream pelton turbines.
Trustpower has said all resource consents were in place and the scheme's design was environmentally-sensitive because no waterway would be dammed and the powerhouses and intakes were compact.
Unison was due to begin building the connecting line to Tutira later this month which would connect to Unison's existing 33 kV line between Tutira and Tamatea.
The project was initiated by the owners of the land on which the two streams flow more than 10 years ago, with Trustpower acquiring the rights to the scheme five years ago.
It was expected to have an annual output of 15GWh and would be commissioned in June next year.
TrustPower had 36 other power schemes in New Zealand and was listed on the New Zealand stock exchange. An electricity retailer as well as generator, it was majority owned by Infratil, which was also a publicly-listed New Zealand company.patrick.osullivan@hbtoday.co.nz