Mangahao River

An Exercise in Discretion

Solo weekend trip

So much for plans. The idea was to leave a car at the Ohau River Road end (Poads road, off Stratton Road southeast of Levin) then get dropped off at the upper Mangahao Reservoir behind Shannon to tramp up the Mangahao River past the hut, over Girdlestone Saddle to Te Matawai Hut for the night; next day up to Arete then out via Waiopehu Track to the car.

I dimly recall visiting the area in 7th Form to do the Northern Crossing, and my mother informs me we camped at the upper reservoir when I was in nappies.  In other words, it's high time to get reacquainted.

Saturday

We're up at 5am and ready to leave Wellington but the plan takes its first hit when one of the cars has a flat battery.  It turns out the last time we filled it up with petrol was 6 months ago so hardly surprising really.   After a jump start we're away half an hour late.  It's light by the time we cross the cute wee bridge at Poads Road and leave one of the cars. 

Shannon is next and we head into the hills past the 126 GW Mangahao power station and the white water canoeing course.  Over the top of the first ridge we realise it's a lot further in then expected and the petrol is low.  So back we go. 

The road in is well formed with a few roughish spots but fine for any car.  It's about 21K from Shannon to the road end over two ridges and past two reservoirs before reaching the upper reservoir.  The mist is hugging the hills and shrouds the other side of the first reservoir.  The occasional shower wanders through.

At 0950 the warmth of the car is exchanged for a sudden dump of rain as I head into the bush.  The DoC sign indicates 5 hours to the Mangahao Flats Hut and up to 10 hours to Te Matawai.  If I want to make it before dark I better get a move on.

The track is rough, rooty and muddy in spots.  A layer of slippery black leaves cover the ground making footing tricky.  From the map the track looks like it follows up beside the river but knowing Tararua tracks, this means it is going to be ducking and diving up and down spurs and into side creeks; which is exactly what it does.

There are four bridges between the dam and the hut which help mark progress.  The second swing bridge crosses the main river and is relatively new (the old one still hasn't been taken out but is blocked off by magic "make-it-safe" plastic tape).

The first real look at the river reveals it is a lot bigger than I was expecting.  I keep a weather eye on it during the morning as the track will be crossing it further up valley.  

In the steep sided valley the sides of the track are a bit crumbly in places and there is quite a bit of clambering required.  On the flat sections tree roots twist across the ground trying to find a toe hold in the stony ground.  This all makes for interesting travel and a couple of rolled ankles; on the same foot worse luck.

Further up the valley a few flats open up, one even has a picnic table; they would be very pleasant stops on a hot day.  

Harris Creek is a bit over half way and it's very high, I seem to be making good time and sure enough it's about 1215 when the Mangahao Flats Hut suddenly appears. Something large moves off into the bush but I don't get a glimpse, I suspect a deer as I've seen no pig sign and haven't smelled any goats.  

The hut is a good size and clean.  Hemmed in by bush it looks down across a small flat to the river.  A quick break to write in the log and a bite before heading on.  It appears that no-one has been here since 13 May.

The track continues up beside the river crossing occasional side streams.  Each one is a welcome sight as it means that much less water in the main river as the crossing point gets nearer.  Glimpses of the Mangahao River shows it is still big and fast flowing.  I manage to catch an eye on a branch which fortunately doesn't knock the contact lens out but is annoyingly sore (and spectacularly bloodshot the next day).

There's one big side stream which at first glance looks dicey, however it's a bit wider down stream so a quick bush bash finds a suitable spot and a handy rock midstream gives something to grab onto.

It's about 2k to the main crossing and one look gives the answer ... nah.  There's no way I'm going into that on my own.  Bush bashing up river shows it is steep with white water rushing over large rocks and the map confirms that I'm not likely to find anything better within a reasonable distance.  Down stream provides no better news.

I figure that it doesn't pay to think about the transport aggravations that are contingent on the decision to cross or not.  It's a bit of a pain but turning back is the right call.  There's no time pressure so it's a more leisurely pace back to the hut. And the rain starts in earnest. 

Back at the first stream, water is now lapping over my mid-stream rock.  I find a suitable branch, remove coat, loop the PLB over my neck and undo waist and chest straps. It's actually an easy crossing but with the main river a few metres away I'm not taking any chances. [A couple of less than ideal calls here - should have left the hip harness done up and it can be risky crossing too close to the confluence with another (especially larger) river - should have tried up stream first]

Back at the hut four early-20 year olds from Palmerston North (and Ohakea) are in residence.  It turns out they arrived at the road end just as Sally was leaving.  They are friendly and chatty and have brought mountains of food, drink and games.  The two women are students and they seem to have been friends from school days.  They invite the solo old (surely not!) tramper to join games of Monopoly cards and Five Crowns while it gets dark outside.  The hut fills with smoke from the fire.
  

Sunday

The morning is misty and with a fair amount of rain in the night there's no point heading back up river to see if a crossing is possible.  The task for the day is to get into cellphone coverage in order to call for a pick up.  This means heading back to the road end and climbing a ridge (either Puketurua track or to Burn Hut) or walking out.  I figure that walking out is the best bet; if there's no coverage on the ridge I've just wasted time and effort.

The other party are just starting to stir when I head out into the saturated bush.  The rain comes and goes and it's quite dim under the trees. The river has certainly not dropped overnight.

The four bridges pass and finally the upper reservoir. There is a lot of water where there wasn't any before.  At about 11.35 it's taken about 2hr45 to get to the road end.  On the road it is initially a jog on the flat and downhills then just on the downhills and finally just walking the long kilometres into town.  Cellphone coverage doesn't come in until a couple of kms short of the power house.  

The walk gives the opportunity to study the hydro set up.  The top dam regulates water flow into the lower Mangahao Reservoir where a tunnel takes water out of that catchment and into the Tokomaru Reservoir in the upper catchment of the Tokomaru River.  Another tunnel takes water from there through the hill and I reckon about 160m down to the power house.

The Mangahao River drains naturally from the 2nd reservoir north and east joining the Manawatu River just before it flows through the gorge.   The Tokomaru River heads north and east before swinging west and south to join the Manawatu River a few kilometres from Shannon.  Water from the power house joins the Mangaore Stream which enters the Manawatu River just down from the Tokomaru confluence.  So the water all ends up in the same place but takes completely different paths on the way.

Apart from the rain the only other things of note are a track marker for Te Araroa (the walkway that runs the length of the country) and the only car on the road; driven by a miserable .... that doesn't stop to pick up a wet tramper 6km from the power house.

In the end there are no lifts and I walk all the 21+ km to the Horseman Cafe on the main street of Shannon, arriving about 2.15 (coincidentally taking about the same time as we took to walk the St Claire half marathon in Marlborough last year).  A hot chocolate revives spirits and it's not long before my infinitely patient driver arrives for her second foray to Shannon in as many days.  Next stop Poads Road and maybe just a quick nip into Levin to visit the Swazi shop.

Although the main aim of the trip wasn't realised and the weather was a bit damp, it was good to get a look at and feel for this part of the Tararuas.  And I didn't mind the rain so much.  There's definitely scope for another trip or two into the area but I think I'll be looking to try that river crossing with someone else.