Good news, the shuttle is realy short and easy but the access is not. You must get access from Porinui Station, as they control the gate the area. Also, a 4WD would be handy; otherwise some walking is in order. Poronui Station PH: +64-7-384-2080.
First series of rapids including the crux are just below the Red Hut. Scouting on river right is recommended, as boat scouting is difficult. First rapid is an easy slide, which leads into a class IV+ rapid. This is comprised of a slide and a couple of 1-2m drops, that have quite a narrow line. Flat pool for about 200m follows.
Next rapid is an easy slide, followed up with a sticky drop on river right. Portage/scout on river right. Following this is a shallow boulder garden with some small drops which leads into the confluence to the Mohaka River. After that is a few hundred metres to a class III rapid. Directly after that is the take out at the hut.
To get the TAKE OUT: Take the Napier Taupo Highway (SH5) east of Taupo for 25km. Take a right onto Taharua Road. Drive down the 20km till you get to an automatic gate, continue driving to till you get to a bridge crossing Taharua River. Take the left turn just before it. Once you get to the Red Hut, continue down the 4WD track, and make sure to take the turn down the right hand side track to a hut on the Mohaka River. There should be a class III rapid next to the hut.
To the PUT IN: Put in is at the Red Hut, next to the Taharua River.