Te Rerekawau Falls (also known as Kaiate Falls) is actually a set of waterfalls - a three-tiered upper falls and an attractive lower falls. It was also formerly known as Shag Falls because there used to be a shag colony nearby the lower falls, which is probably how it got its Maori name. By the way, shag in this context is a type of cormorant bird that dives from the sky to catch its prey. It is not the Austin Powers interpretation of the word.
For more information on this waterfall such as...
maps
directions
detailed descriptions
refer to A Guide to New Zealand Waterfalls (Story Nature Press).