I found this trail one of the best in Waitakere region. It could be quiet challenging after a rainy period. Lots of river crossings and some awesome views. There is a big fallen rock in front of Mokoroa falls, an awesome place to have a light lunch before heading back.
Unlike other walks this one starts downhill
Since I didn't want by boots wet, I walked half the way barefoot
Mokoroa falls
More information: http://tramper.co.nz/?view=object&id=2418