Wairua Falls completely dry with all water diverted to make hydroelectricity.
Whangarei Volcanic Field erupted basalt lava off and on over the last 4 million years. Eruptions produced scoria cones and lava flows. Wairua Falls cascade over the side of a 500,000 year old lava flow from Whatitiri Shield Volcano. These basalt flows dammed the Wairua River and created the huge Hikurangi Swamp upstream. The Wairua Falls are dry for a lot of the time because the water in the river is diverted down a race to drive a small hydroelectric power station that was built here in 1920 to provide electricity to the Portland Cement Works.
Why are the Wairua Falls often dry?
At this location the river falls over the side of the lava flow and erodes out softer rocks that were once the side of the valley that lava flowed down.
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174.084280729294
Directions/Advisory
Carpark at end of Wairua Falls Rd, off Mangakahia Rd, is right next to the lookout over the falls.
Watch out for backing and turning cars in the carpark.
Middle Pleistocene, erupted about 500,000 years ago.
Zealandia Evolution Sequence
Pākihi Supergoup: 5 million years ago – present
Links
See Hayward;B.W.;2017. Out of the Ocean into the Fire. History in the rocks;fossils and landforms of Auckland;Northland and Coromandel. Geoscience Society of New Zealand Miscellaneous Publication 146;336 p. Fig. 12.25.;