A Guide to Lake Karapiro

A typical long, skinny hydro lake, Karapiro is the lowest lake on the Waikato River.

Completed in 1947, the dam blocking the river is reached from the village of Karapiro, just off State Highway 1 south of Cambridge.

The top end of the lake is about 30 kilometres upstream, where the tailwater from Arapuni Dam enters. At this end the water level is well above the lower dam and there is a significant flow. The lake has an interesting 90-degree bend at Horahora, marking the point where a couple of million years ago a major earthquake lifted the riverbed, changing the Waikato’s direction and destination from the Firth of Thames on the east coast to the west coast at Port Waikato.

Karapiro is an important recreational zone for the Waikato area – it is used for powerboat racing, rowing, water skiing, camping, duck shooting, sailing, swimming, picnicking and fishing. As a fishery it is not heavily utilised, especially in the lower 25 kilometres of water, which is where most of the other activities take place. We will discuss the tailwater below Karapiro Dam, as well as the lake itself.

Below Karapiro Dam

The water below the dam is unobstructed right through to the Tasman Sea at Waikato Heads.

Sea-run trout follow the whitebait upriver in early spring, and it’s not unusual for trout to congregate below the dam, where they are visible from the road on top. It’s possible to fish this water from the banks under the dam. However, there is limited back-casting space, making spinning the way to go.

A little further downstream access is available on the true left bank (across the dam from State Highway 1) by walking down the steep road through the old quarry. I advise wearing a lifejacket here – the bank drops away quickly and the current is strong.

Some anglers arrive in boats from Cambridge and pull them up on the shingle while fishing the banks along this stretch. Be aware that the river can rise quickly when the dam starts generating, so don’t get too far from the boat and be sure to wear a life vest.

Spinning is popular in this area, although flyfishing with a lure works well and dry-fly fishing with caddis imitations after dark is probably the most productive. Brown trout, in particular, smash the flies as they are skidded across the surface.

I had the immense pleasure of fishing this stretch of water with one of the very few experts, Richard Wagstaff. We put my boat in at Cambridge (because Richard had sacrificed a third propeller on his boat to the vicious Waikato rocks the weekend before) and carefully negotiated the treacherous water upstream. On the way Richard pointed out gentle eddies, sheltered drop-offs and backwaters where he had caught fish. There are fish all through this run, but getting your terminal tackle to the fish is the challenge.

We tied up to a tree below the quarry. Richard had checked the flow and it was about 270 cubic metres per second (cumecs). Although there were quiet places to fish, the water level was too high to get the boat into most places where it could comfortably be secured.

Richard cast a sinker on a spinning rod with a Rabbit fly, while I used a Woolly Bugger on a fast-sinking fly line. No success. We crossed the river and tied up to the other side, my guide suggesting I wade and nymph the edge. Four browns and three rainbows took the tungsten-beaded nymphs in an hour and a half, their well-conditioned bodies flashing in the sun as they struggled against the rod. I kept a fin-clipped rainbow, which was full of caddis nymphs.

While we fished here the water dropped a metre, exposing the terrain that had been covered when we first arrived, making the fishing even better – and the potential for outboard mortality worse.

Richard reckons the best fishing is when the flow is around 160 cumecs. Everyone I spoke to who has fished this water stresses the dangers. The water can rise fast too, and it’s easy to get trapped or possibly have a poorly-secured boat drift away while fishing from the shore. We kept our life vests on, even when fishing (although I asked Richard to take his ‘lucky’ blue one off when I photographed him).

Further downstream we tied up to yet another tree and fished a pool where the current gently swirled around, bringing a steady supply of brown beetles to the fish rising in the centre of the eddy. We had less success here, the trout co-habiting with massive carp, their multi-coloured bodies making them obvious in the fairly clear water. Schools of mullet grazed on the bottom, their sharp tails and silver bodies remaining in position until I almost stepped on them, triggering a mass evacuation.

Some boats troll the water between Karapiro Stream at the southern edge of Cambridge and the dam, working the edges where the current is slowest. Trolling downstream is effective. Apparently this water is also jigged, but I have not spoken to anyone who has used this method. Whirlpools and sunken logs dog this section of the river, and good boats with strong motors and skilled drivers are required. I miscalculated a rapid on the way down and put another ding in my skeg.

The dam to the Little Waipa mouth

A massive volume of water is included in this section, which is over 20 kilometres long. All the water sports on the lake take place in this area, except for fishing! That’s not quite right – there are fish right through the lake and this section does get fished, however finding where the fish are takes time, so many anglers move on to the easier fishing. Of course, when the anglers are away the fish will play, and the best evidence of this is Ewen Pilcher’s story in the sidebar on page 22.

Ewen fishes this area frequently and his comments are similar to Fish & Game Wildlife Officer, Ben Wilson’s. Ewen works his way up the lake, fishing from the promontories and anywhere a stream enters. He has developed a series of spots at which he spends half an hour to an hour, depending on how the fish are responding. A spot that regularly responds well is off the pontoons used by the rowing skiffs.

Ben has successfully fished the lake from the shore at points south of the Horahora Bridge.

“Fish from any point,” Ben says, “Especially if it is rocky and drops into deep water”.

There are some great looking spots along this stretch of water. If you’re boat fishing, try trolling or jigging the edge of the lake from the Horahora Bridge down to the Karapiro Domain. It will probably fish best in the cooler months, especially at night or early in the morning. Both sides hold fish, so work the water between three and five metres deep; where the drop-offs are deeper than this, get as close to the shore as possible and only fish if there are signs of fish on the fish-finder.

Little Waipa Mouth to the Arapuni Dam

This section of water generally holds the best fish, according to Ben. Many anglers fish off the mouth of the Little Waipa, especially during winter nights when fish are making their spawning runs. A boat is pretty well essential here – the broad weed beds won’t allow much in the way of a cast from the shore. Around 1500 rainbow trout are released from the mouth every year, and every so often brown trout are also released.

In my experience, the better fishing starts where the water is still flowing. There is about half a kilometre of water that trolls well, finishing at the trolling limit – a sign marks this point. Trolling with black and gold or green and gold Tasmanian Devils with a large fly – such as a Green Orbit or Red Rabbit – a metre ahead of the Devil often works. Keep just off the banks, far enough to avoid losing gear on the snags that are on both sides – easier said than done.

Just above the trolling limit, the fishing from the shore is good. Fish always sit along the edge on the Horahora Road side. Either retrieve a lure-type fly or nymph the edge. A spinner will work and I’m sure a dry fly would be effective in summer. Access is really limited, but there are a few little points that will accommodate an angler. If fishing from a boat above the trolling limit, it must be anchored.

There is a section of fast, shallow water just below the spillway that can be negotiated in a boat. However, it is difficult to secure the boat, except at the top, where a lure can be cast out and allowed to swing in the current very effectively.

There is reasonable access from the shore on the true left bank, and some anglers beach their boats and walk upstream to reach good water. It’s easiest to spin here, generally by casting into the deeper water between the visible rocks and letting the current swing the lure down and across.

Upstream of the spillway is where the good fish are. A boat can be used to get into the pools here, but it’s a little like the water below the dam: fast and unpredictable. There are a couple of good pools in this section, and the good news is that Fish & Game and Mighty River Power have negotiated to put in access trails to the Brandenburg Pool and other fishing spots.

The track starts on the road between the powerhouse and the dam. The trails along the lake edges will be lengthened over the next few years and we can expect better access to this great water. Anglers should appreciate the contribution Fish & Game has made to the future of our sport with this initiative.

The best fishing up here tends to be after dark, when the flows through the dam drop. The caddis throughout the Waikato River are prolific, and skidding caddis imitations across the surface in the dark can be very productive.

Finally, although only 10% of the trout in the lake are estimated to be browns, about 30% of those caught are over 4.5kg (10 pounds)!

My first ‘brownie’

Ewen Pilcher is a regular visitor to Karapiro’s waters and knows there are some great fish lurking in its murky depths. The following is how it all started…

“It was April 1998 and I was taking a ‘sicky’ (as fishermen do). I thought I’d try Kelley’s Landing at Lake Karapiro, and got down there around 6.30am. I was so new to fishing at the time I didn’t even know whether I was doing it ‘right’ or not.

I started off with a Woolly Bugger, but had no luck. So I changed to a Mrs Simpson, cast a few more times, varying my casts in distance (due to being unskilled at distance casting!), but finally got one right and out it sailed OVER the weedbed that was only some 30 feet in front of me.

I started a slow retrieve. BUGGER! Weed. But as I tried to pull the hook free without losing my only Mrs Simpson, the bloody thing started to move away from me.

Really excited, I was! Nobody else there to ask, “What should I do?”

This hog moved out into deeper water at an alarming rate and I was just trying to remember what Bert (Robinson) had told me: “Keep the line tight, but let it go if it wants to.”

However, when I saw the spindle of my reel coming up I got a bit concerned, and decided to try and slow the monster down. I put extra pressure on the reel and managed to turn it and retrieve line.

After very gingerly getting the trout to shore, I then had to get it onto land. My net was insignificant compared to the fish, so while holding my rod high, I took off my slippers and socks, pulled up my trou, waded in and kicked it as far up the bank as possible. I then jumped on it to make sure it wasn’t going anywhere.

If anyone had seen all this, and my antics afterwards, I would have been committed.

I then took it to my mate’s place to get it weighed (and skite). The brownie hen weighed 12lb 2oz. So yes, I do have a photo of it, and no, I didn’t get it mounted. Instead, I ate it, ’cos I thought it was so easy I could go and do it again, any time. How inexperienced is that?


 This article is reproduced with permission of
New Zealand Fishing News

2009 - by John Muphy
Re-publishing elsewhere is prohibited




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