Thursday, 14 April 2016

Benmore Dam- the Business End

Catch-up

We wanted to do one more tiki-tour before we left Omarama. A trip to check out the mighty Benmore Dam which was only about 15km down the road from us, on SH83 heading towards Kurow. 

We'd checked out the smaller dams and hydro canals that zig-zag across the MacKenzie Basin many times over, we'd visited the power stations at the top and bottom of the Tekapo Canal and the three on the Ohau Canal, we've been to both sides of the canal at the top of Lake Benmore, so now it was time to check out the business end of Lake Benmore.

It's not long down the road before we come over a rise and see a lake ahead of us. This is Lake Benmore, not the main body but an arm that heads west just before the dam. Lake Benmore is New Zealand's largest man-made lake; it's 74.5 square kilometres with a 116 kilometre shoreline. It holds 1.5 times more water than Wellington Harbour.


Tucked into the corner of this part of the lake is Sailors Cutting, with a very popular campground, boat ramp and a sheltered boat harbour.


We turn off at Otematata- a town, like Twizel, that grew as a result of the camp that formed there in 1957 to house the workers constructing the dam. At the height of it's growth in 1964, the town had a population of 4,166. The dam was commissioned in 1965. Otematata now it has around 250 permanent residents with a large increase over summer as holiday makers set up camp nearby and around the shores of Lake Aviemore, which is downstream from Benmore.

We pull into a gravel patch below the dam- here's a panoramic shot which is 4 photos stitched together- I make work for myself, I should just use my phone for pano shots.


The Benmore Spillway is about 500 metres long and 55 metres wide on average, it can discharge an amount of water 10 times the amount of the river flow. water flowing down the spillway is deflected at the bottom into a wide arc to dissipate its energy before entering the river.


We headed up to the lookout, stopping to take the obligatory photo at the entrance to the power station.


I was a little disappointed with the trees growing below the lookout as they hadn't been chopped or trimmed so the 270 degree view was interrupted at regular intervals with pine tree spires.


I managed to avoid them by zooming in on the Waitaki River below the dam, the dam wall road is at the bottom of the photo. Isn't the colour scheme amazing? Typical Central Otago country. And yes the water was that colour, imagine what the view would be like in autumn when all that green would be a brilliant shades of gold. 


The lake behind the dam wall, there's even a tiny house boat tucked into the willows in the corner below us. 


We drove across the dam wall. Correction. David drove across the wall, I walked...


...so I could take photos looking down over the penstocks...


...and along the wall. Check out how huge that is, there are cars parked down the bottom there, to give you some perspective.


Benmore Dam is 110 metres high, 832 metres long at the top (no wonder it took so long to walk it), 448 metres at the bottom, and 11 metres wide at the top.


Benmore Dam is one of the largest earth dams in the Southern hemisphere and the power station is New Zealand's second largest hydro power station (after Manapouri which we visited early in our journey), with a generating capacity of 540 megawatts (720,000hp). 


David decides I'm walking too slow and drives back over to pick me up, giving me a chance to grab another photo for the blog header. Actually, he realises that it's a long way over, and it's hot outside, so comes back over to collect me.


The top of the spillway- wouldn't it be great to see that flowing. The spillway can cope with 3,400 cubic metres of water per second. Imagine riding that in a kayak or wake board.


There's another lookout beside the spillway on the far side, the shutes really are huge. Again, you can see a vehicle parked up on the top for a size comparison. The driver of the vehicle was working away somewhere deep inside the spillway workings, banging and crashing about. He also had his radio playing real loud. 


Large pylons marched away up the rocky hill behind carrying off their valuable booty. 


Benmore straddles two provinces; the spillway is on the Canterbury side of the Waitaki River and the powerhouse on the Otago side of the river. Further down the river is wide and there are many whirlpools, eddys and shallow bays reaching back into the willows. 


We carry on down the north side of the river...


Right round both sides of the lakes and along the river are dozens of interesting camping spots. Small and large grassed areas, some right beside the road, others tucked behind trees and right on the waters edge. There are also plenty of permanently parked caravans waiting patiently for their owners to return either for the new fishing season &/or summer. 

Of course most of the best spots have been taken by permanents but there are still more than a few ideal spots to park up for a few days. We will have to return here with the 5th-wheeler when the fishing's good.


It's not long before the river turns into the next lake, Lake Aviemore, another man-made lake with a dam at the bottom, all part of the overall Waitaki hydro scheme. The lake wasn't that appealing on our visit, as a howling gale was whipping straight down the lake.


I spotted a sign on the other side of the road, and we pulled up to take a look. Deep Creek looks just like it says, a very deep pool; there's boat access and it reaches way back up a narrow ravine behind. Obviously a creek must feed it, up the back somewhere.


Finally we're approaching the Lake Aviemore dam and Aviemore Power Station.


We cross over the dam and I can see off in the distance the third man-made lake of the scheme; Lake Waitaki. Water from the three MacKenzie Basin lakes; Tekapo, Pukaki & Ohau, pass through eight power stations on its journey from the Southern Alps to the Pacific Ocean, there's just one more power station after Aviemore and that's Waitaki at the end of the next lake. All eight power stations are operated from a control centre in Twizel.


We head for home, up the south side of Lake Aviemore....


...with one last stop to take a photo of this lovely old woolshed. 


Hmm......I'd love to do a tour taking woolshed photos....



4 comments:

  1. We were at Lake Benmore just after Warbirds, & we walked across and back on the dam road. One day I'll return to ride my 36" wheel unicycle.
    Fabulous place to spend some time.
    Your research of places and thoroughness is most impressive.

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    1. Thanks Jimu, it's a pretty impressive power station isn't it. Perhaps you could time your unicycle ride with the next spillway release- either ride the spillway and/or busk for the visitors! :)

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  2. Nice to see you visited my hometown, I grew up in Otematata as Dad was an operator at Benmore Power Station - that was back before the stations were all automated and run out of Twizel. A great place to grow up with all those lakes, rivers and hills to play around in. Spent many a time visiting Dad at the Power Station, even had a few Xmas/New Years dinners there when Dad was on shift work - power generation didn't stop for the holidays!
    By the way - Deep Creek has a walking track that heads back into that ravine for about an hour or so - I walked it many years ago in summer but it would be lovely to do in autumn.

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    1. Hi Lisa, it sure would have been a great place to grow up, I loved the rugged hills and the smaller pools and wetlands around the lake edge. I saw that track at Deep Creek and thought we'll have to return when we had a bit more time and the colours had turned.

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