Tauranga-based TrustPower has outlined plans to divert between 30 and 40m3/sec from the river through an expanded Wairau power station. The water would then be conveyed through 46km of interconnecting canals and penstock pipes to five small power stations located at regular intervals between Birch Hill and Marchburn.
TrustPower has been negotiating with landowners affected by the scheme for several months and plans to file for resource consents later this month.
TrustPower proposes to leave a residual flow of between 10 and 20m3/sec in the river, but conservationists say 30m3/sec would be the minimum required to maintain a sustainable fishery.