Wairoa water supply dam, Auckland.
by Stereoscopic Society of New Zealand additional members 2022-07-02 22:52
Wairoa water supply dam, Otau valley in the Hunua range. 5/08/09. It has my vertical impermeable (VIB) barrier of clay/silt, on centre line, as opposed to the downstream sloping barrier in most earth dams, to that time, which followed the model of the USA, Cherry valley dam. The benefits of the VIB are, easier construction, less seepage loss, better stability, thus steeper slopes, and less earth fill. Curving the dam was necessary to fit into the complex Otau Valley.
The VIB was then included in design and construction of the biggest of Auckland’s dams, Mangatangi.