At a Glance
The Motukawa Scheme makes use of 99 metres (m) of elevation difference between the Manganui and Waitara Rivers to drive three generating sets, the last one was added in 1938.
In recent years, we have made significant efficiency enhancements. In 2005, we installed a 200 kW turbine in the Motukawa water race, taking advantage of the natural fall in the supply race system. In 2007, we installed pumps to lift water about 4m out of the Mangaotea Stream into the Lake Ratapiko supply race. These improvements added to the scheme’s power output — and help make better use of the natural resource.
An upgrade project, which was completed in 2012, enhanced the efficiency of the Station by 15%. Our state-of-the-art computer fluid dynamics modelling, suggested an 8-10% efficiency gain will be achieved. The upgrade will also mean our equipment is set to perform for many years to come.
Environment and recreation
As part of our environmental commitment we have installed a fish pass at our intake weir on the Manganui River, which allows migrating species to swim both up and downstream past the weir. The fish pass is stepped to allow for easy passage, and has had extensive riparian planting completed to alongside and upstream to improve water quality. We also run a successful trap and transfer programme for Longfin Eel during migration seasons.
We gained new Resource Consents in 2001, consents will again be due for renewal in 2022.
Lake Ratapiko is the hydro-storage lake for the scheme, and is also a popular recreational lake which is home to the Jet Boating New Zealand Taranaki Branch, and the New Plymouth Water Ski Club. Both groups host regional and national events on the lake.