Mangorei Power Station  The Mangorei Power Station is a hydroelectric power facility near Mangorei in Taranaki in New Zealand which makes use of water from the Waiwhakaiho River (which is often written as Waiwakaiho) and the Mangamahoe Stream catchments. Of the first 14 publicly available electricity supplies in New Zealand, seven were in the province of Taranaki. Most of these were hydroelectric schemes, utilizing the seasonally consistent water supply provided by Mount Taranaki’s many streams. This development was driven by the demand for electric lighting by both town and rural dwellers plus farmers wishing to power their new electric shearing sheds, milking machines and separator. In the late 19th century the New Plymouth Borough Council decided to investigate its options for constructing a hydro-electric power station to supply the town with electricity as well as providing a water supply. The nearby Waiwhakaiho River was identified as a suitable source of water. In 1898 a completion was held to design a scheme. The completion was judged by respected engineer Richard Liron Mestayer (1843 - 1921). The council decided not to proceed with any of the schemes put forward and instead engaged Mestayer in 1901 to design his own scheme, which was subsequently accepted. His design called for an intake on the Waiwhakaiho River from which water was conveyed to a powerhouse first by a tunnel that passed under the Mangamahoe Stream to a forebay on the hill, from which a diameter steel penstock conveyed the water down to a manifold outside of the station from where the water was split to supply two turbines. Mestayer's design was accepted, which lead to a construction contract being issued on 13 July 1903 to McWilliams and Andrews to build the scheme. The tunnel was dug from the outlet, from a side drive about 16 chains (322 metres) from the outlet, and from a deep shaft about 21 chains (422 metres) from the outlet. From the side drive and also from the shaft the tunnel was driven in both directions. The alignment of the tunnel was laid out on the surface by Sladden & Palmer, Civil Engineers and Surveyors, and then transferred to the bottom of the shaft by means of heavy plumb bobs suspended from the top by very fine wires, with the plumb bobs themselves hanging in buckets of water to dampen their movement. The line thus transferred was produced in both directions by means of a theodolite.