THE WAITAKI FISH LADDER

New Zealand Herald, Volume LXXII, Issue 22071, 29 March 1935, Page 15

THE WAITAKI FISH LADDER

Sir, —Your items at varibus times of late in connection with the fish ladder at Waitaki are interesting, and I am sure anglers in general are grateful ..for this news. As a youth I lived for many years near two splendid trout and salmon rivers in the west of Ireland. Since those far-off days I have been keenly interested in these fish and fishing. I have spent many happy and instructive hours watching salmon on the "run". Their efforts in negotiating what was called " The Salmon Leap" on one of these rivers never ceased to secure nw undivided interest; I spent many hippy hours watching these fish makina their way from the lower reaches of the river up this "leap" to the higher and so to the lakes from which it flowed. The "lean" was nearly 60ft. in height, the river tumbling down from above through huge boulders in three main cascades and several smaller ones. From your description of the ladder at Waitaki I would say that there was a much greater flow'at the "leap". The fish came to the swirling pool at the bottom and with a short rush up thov went some 14ft. to 15ft. into the first hole, scarcely resting there until tliev made their way in splashing rushes through the short lengths and so up the other , .and long cascades. It was the sj)eed with which most of the fish got to the top. Once having started on their rush to surmount the obstacle in their way they made little delay. It certainly was a wonderful sight to see the big gleaming fish leap such a height with such agility, [{everting now to the lndder at Waitaki and endeavouring to compare the means created there to allow the fish to continue their "run" up river with the "leap" I write of, it seems to me that the fish in the Waitaki following the river up to the dam and there meeting with a series of rushing <iutlets and spill-way fall are non-< fjlussed as to their next movement. Salmon are not, in my opinion, as venturesome in exploring as trout, and I am of the opinion that it is trout that have gone up the ladder at Waitaki. I think if the builders of the ladder had made the steps of the ladder of greater breadth, that is, from sjide; to side, and the stons of greater i height, say, 6ft to Bft., and more at the lower end, with perhaps a little more water, the fish would have been more ready to accept it as a certain route to the place of their desire. It seems to nie that the attempt, laudable in every way that it is. is too simple. The "leaps" are too short, and compared with the amount of water which allowed them passage up to the foot of the ladder the quantity allowed to flow down the ladder is not encouraging enough to tempt the fish into an endeavour to try that way, The velocity of the flow is too gi'feat at the outflow from the turbines or spillway, but not great enough at the ladder. I do not claim to be an authority on this matter, and am simply comparing a real and an artificial "leap." Salmon Leap.