Reel Life , Central South Island Region, June 2009.
Graeme Hughes.

Several weeks have passed since the floods of April and May, Although normal volumes have resumed  flows in the Waitaki Valley lakes and Waitaki River remain turbid. While boating the Waitaki River mapping and evaluating historical salmon spawning side streams with NIWA scientist Gavin James, the effects of 1500 cumecs, almost 5 times the mean annual  flow, became evident. Considerable bank protection has been washed away in  many areas  resulting in significant loss of productive grazing land and the fences that bordered them.

In the wake of a 1500 cumec flow, bank protection will be required in many areas of the lower Waitaki River.

Log jams are numerous on low lying islands and at the top of smaller braids.  Most noticeable were the huge piles of uprooted gorse wedged into willows or  obstructing entry to smaller braids. These observations  illustrate clearly the significant increase in gorse infestation of banks and islands of the Waitaki. Many “old man willows” killed by fairway spraying decades ago, familiar navigational hazards to many jet boaters over the year, have tipped over. While some have disappeared completely others lie submerged creating impressive standing waves.

Although the high flows have many benefits, the timing could not have been worse. The salmon spawning at that time would have been at its peak and most redds will have been destroyed. The same can be said for the Hakataramea River salmon. The flood flows coincided with the first year for many that autumn river flows were of sufficient volume to attract salmon into this important spawning tributary of the Waitaki River.  Over the last five autumns low flow conditions have prevented salmon ascending the river to historical spawning grounds. Salmon were observed spawning in the mid reaches of the Haka River in mid April. The spawning effort of these fish  has been wasted due to the untimely flood flows.

The normally docile Hakataramea River in flood mode. 130 cumecs destroyed any salmon redds excavated during April.

One thing is for sure, didymo has taken a severe beating and with reduced sunlight and the continuing flow of discoloured water in the Waitaki River, its inevitable return may well be slower than usual. In the main stem it is difficult to find any evidence of didymo, however in some smaller side streams, on stable substrate, didymo remains, albeit looking “worse for wear”. 

Winter Fishing

The Waitaki Valley lakes including Lake Ohau remain turbid, visibility is reduced  to about 300 to 400 mm and the attraction of winter fishing is somewhat reduced in the lakes and I suspect in the lower river where turbidity  is increased. The lower river is open to fishing below SH 1 for June, July and August. Even though trout will take lures or baits in reduced visibility I’m guessing that  the string of heavy  frosts have reduced the enthusiasm for winter  fishing ventures rather than the grey green colour of the water. During the middle of the day the calm, sunny conditions are picturesque and look quite inviting, however despite these brilliant days, on my irregular trips up the valley I have only seen two anglers out there doing it.

A pre-flood arrangement to winter fish by boat some of the CSI ‘s high country lakes at this time does seem overly optimistic . A recent flight in the high country during the annual Canada goose trend count showed minimal clear water fishing areas are available which is a little surprising considering the  period of time lapsed between flood flows and normal winter flows. This proposed fishing session involves 3 or 4 days  and while common sense would suggest a postponement, the arrangements made several months ago are non-negotiable. High country camping at this time of the year has temperature related challenges, adding water turbidity to the equation casts doubt on this being the most successful of trips. My guest angler, presently on holiday in the high temperatures of Europe, will find the low temperatures and severe frosts  of Lake Ohau more than he bargained for and shaking him out of his sleeping bag in the mornings will be difficult.
As the “chief guide” and responsible for a good catch rate I’m thinking it may be time to open up the tackle box, the one with those lures you buy “just in case” and see if  those high viz’ trolling lures really do work  in  low viz’ lake conditions.

So many lures (and a selection of new ones to try) and so few days to use them. A selection of “eye popping” trolling lures that lake trout in coloured water will be unable to miss and hopefully unable to resist.

Salmon Spawning

The poor visibility in the Waitaki River prevented a whole of river aerial salmon count which was scheduled for the 27th May.  In the Hakataramea River, the flood flows of 130 cumecs dropped quickly and at 6.3 cumecs, just above the annual mean, it was running clear. A foot survey of the lower river in early June showed encouraging numbers  of fresh run salmon moving upriver from the Waitaki.
An aerial count on the 11th  of June revealed the following:

 Hakataramea River Salmon Count (Aerial) 11th June 2009.

 
The numbers of Hakataramea salmon observed late in the season were encouraging, over double observed in the previous year. On the 30th May 2008, 103 salmon were counted in the same area of river. 

On the return flight I surveyed a short stretch of Waitaki River, a well used spawning area and where the river was generally shallow.

Waitaki River
Above State Highway 82 Bridge from Kurow Holiday Park river frontage to top of J Nicol’s property. (true right bank)  “Kurow” 260 I 40, 095 063 to 092 065
(Distance)  750 metres 

Live fish Dead fish
  85  2
River discoloured, visibility reduced to approx 400mm, river flow at 320 cumecs.

With the late run of salmon exceeding expectations, perhaps the total run will have been better than had been anticipated. 

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