2010 Update:
The Pool Reports have not been updated for 2010 as it has been a very dry summer season with only two minor floods over 200 m3/s in May and no material changes to the pools.
During May & June in particular the Hydro Pool has been a most consistent performer yielding many big brown trout over 5 pound.
(Most have been hooked on a wet line using an olive woolly bugger…) i.e.:
Another Tongariro Trophy – the trout that is…
Congratulations to David Larner from Clarendon (South of Dunedin) with his trophy 13.9 pound (6.3 kg) Brown jack, over 30 inches (78 cm) long, Hydro Pool, 21 June.
(Now being mounted by Rick Jenkins at Taupo. Rick says this is one of the best conditioned browns he has seen for many years.)
2009 Update by Tongariro Fishing Guide Andrew Christmas
Hydro Pool 
(Looking up river to the Hydro Pool from the pathway along the true LHS above the Koura Street swing bridge)
Hi all,
Once again the week has rushed past and I find myself wondering which pool I should try and tell you all about and letting you all in on secrets that I have picked up over the years. Choosing a pool to report on is not that straight forward as I have to have been in there recently so I can give an accurate up to date report of it and part of me wants to keep it for myself if it is fishing well. But here at TRM we don’t believe in secrets and the only and the best way to get know a pool is to get out and try it out. That’s why I don’t mind telling you about one of my favourite town pools – the Hydro.
Looking up river from RHS towards the Hydro Pool beach on other side)
The Hydro must be one of, if not the most popular and well known pool on the Tongariro and will feature in most books and magazines dating back to the early days, even before Ross and Pip’s time. It has always been well known and well respected for it’s wetlining qualities. In the early days when the Tongariro was becoming famous this pool helped put the river on the map and gave the Tongariro the famous name it has now. Over the years, like all the Tongariro pools, it has slightly changed with different parts silting up and other parts becoming deeper but in general it has held its shape and character well. Many stories have been told on the bank of this pool and many huge fish have been captured, I never get tired of chatting to the old boys that can no longer walk far as they have stories that will be forever lost if not heard now.
(Looking down river from true LHS)
I guided the Tongariro this week as usual and had some good luck in the Hydro, so what I am about to let you know about now is very recent news and is right up to date. The photos of Angela below and her first ever trout were taken just on dark in the head of the Hydro – not a bad brown for her first fish. (Note from Ed. Sorry Angela – I lost your photo!) Great to see these fish still holding in the Tongariro – the Hydro being a great place to target brownies in.
(Car park in Kutai Street is very convenient to walkway to Hydro Pool and makes this pool a popular choice)
The Hydro pool is a long pool which can accomodate many anglers and offers great opportunities for both wet liners and nymphers with the best wetlining being from the head of the pool all the way to the tail and the best nymphing being from half way up the pool and continuing right the way to the start of the Never Fail pool above. Half way down the pool there are some huge boulders which are scattered right up under the cliff and with a good cast and a heavy set of nymphs you will pick fish up seeking cover behind these. If you are a magician with the wet fly swinging a Wooly Bugger or Yellow Rabbit past these rocks you will usually fool fish into striking out resulting in a solid hook up. Traditionally this is a wetlining pool and even today you will find more guys wetlining than nymphing, but the head is definitely best attacked with a set of nymphs or glo bug. A lot of fish can be caught out found sitting on the gravely lip where they are waiting to shoot on up the faster water and enter the Never Fails and/or Kamahi.
(DoC notice at swingbridge indicates access to and position of Hydro Pool)
Access to the Hydro is awesome. You can drive down Kutai Street and park the car at the turning circle to access the true left bank. From here the entire pool can be fished. A long cast is sometimes beneficial to hit the other bank and even then wading out to your hips made be needed. The only way to fish the true right would be to either walk across the Major Jones swing bridge and turn right as if you were walking up to Kamahi and drop over the bank and into the hydro. Alternatively you can wade across the other side if you know what you are doing and are a confident wader. About half way down just behind the boulders there is a sand bar and if you proceed with caution you can shuffle your way across and access the true right of the Hydro. In the past there has been ropes and all sorts of things to get to this side but they have been removed. The fishing is not that great over there and it is a fairly limited cast due to high banks and overgrown native cover so to be honest I would prefer to stay on the car park side and fish with everyone else. I have only ever seen a handful of guys on the other side and they have not been guaranteed fish after all their effort.
(DoC notice above the Hydro Pool on the river walkway along the LHS)
Another important part of the pool to target is the stream that runs in on the true right bank, called the Mangawhitiwhiti. This is a main spawning stream for the Tongariro brown trout. Wetliners seem to love this spot and you can comfortably wade almost to the confluence of it and throw your wet hard against the bank and allow it to swing right through the main lie. Looking down off the bank you can quite often see browns sitting in here waiting for the right time to make the jump and head up into the shallow stream for spawning.
(Looking across the pool from the LHS towards the mouth of the Mangawhitiwhiti)
Like the rest of the river there are no secret patterns with wet flies or nymphs it really is just a case of being in the right place at the right time and chucking that fly in such way that they can’t resist. My advice while fishing this water is to talk with your fellow anglers and make sure everyone is clear on which way guys are moving as wetliners can get snarky with nymphers going through their traditional wetlining pool.
The Hydro does have it’s fair share of snags and fishing fast sink tip lines you will pick them up but at least you know you are getting down to the fish. These snags are generally large rocks so pulling into them and letting go again will generally get them to jump back out. If you keep finding these problems just try retrieving a little faster to get that fly off the bottom a wee bit. Most of the snaggy structure seems to be at least half way down the pool and at the mouth of the Mangawhitiwhiti but they are by no means reason not to fish this water as it is very productive.
All in all this water is usually very productive and exciting during the spawning runs and really is a social place to be if you like having a chat as much as you enjoy fishing itself.
Where the existing track ends down the bank, take a wading pole and turn hard left – to carefully wade and stumble across the riffles to the island.
On the RHS is a delightful pool being targeted by Guides for some reason… they even come down in rafts to fish this pool…If you stand still on the bank you can even smell the fish in this oh so inviting pool. Take a wading pole.
From the island there is easy access up to Kamahi – a beautiful pool where one of our inmates landed a superb ten pound brown jack on a five weight rod after a 35 minute struggle on his first visit.
Hydro Pool 2005 Report
For the Hydro pool we quote from an experienced angler (report August 9 by Ian Shackelford) who mentioned how he caught 16 fish throughout the river during a weeks fishing, how it was hard with very clear conditions and spooky fish (we have all been there) then commented – the Hydro was far and away the best pool. He used beaded h&c combo size 8 & 12 for 85% of hook ups. He summarised the relative performance of the Hydro perfectly.
It is within easy walking distance (in waders) heading south up the Tongariro river side walking track past the swing bridge. Alternatively, parking is close by at the end of Kutai Street. The usual procedure is to ask those ahead of you where you should join the procession as often nymphers are mixed up with wet liners doing the famous Tongariro shuffle, to the amusement of tourists watching.
From interviews with Hydro devotees – use what ever you are most comfortable with. John is sure fish sense it if you appear hesitant. You need to send a clear message of confident determination down the trace to project an image of controlled aggression, let them know their time is up, they have to bite that lure.
Always hesitate before you enter the Hydro. The fish wait and relax more out of the current in the less turbulent water so are often easier to hook there. Constant casting pressure and thrashing the water forces them into the deeper gut across under the high bank just beyond reach of most. So once again (borrrring) we plead.
The common fault is excessive enthusiasm from keen anglers who wade in too deep and scatter trout resting in the lie and spook them to make it very hard. (Yes, I know Stella has been saying this for years too.) It still happens every day. Follow the guides who always fish their feet first and cover all the water – close in first, then middle for diddle, then far out, then move. Forget trying to reach the opposite side. Wading from the LHS of Hydro is easy.
These pool reports were supposed to identify any differences after the big 2004 flood. The Hydro has certainly changed and is much shallower. This is evident by anglers now wading right across. Fortunately the productive ability appears unaffected. Perhaps the fish move through a little quicker and rest higher up the RHS in the old Boulevard, below the high bank. The irresistible attraction of the Hydro to trout are new spawning smells oozing from the confluence of the Mangamawhitiwhiti Stream. It is well known for producing trophy browns early in the season. It can also be fished – with difficulty, roll casting techniques and a landing net essential – from the RHS on either side of the M…. Stream.
New DoC signs erected at May 2007 to guide anglers and walkers past Hydro Pool up towards Stag Pool.