Periodic rise and fall of Lake Wakatipu 18 Nov 1877
On Floods in Lake Districts and Flooded Rivers in general, with
Methods adopted for their Prevention and Control by H. P.
HIGGINSON, Mem. Inst. C. E. - read before the Wellington
Philosophical Society, 2nd February 1878.
Transactions and Proceedings of the New Zealand Institute 1877

While at Queenstown, on Lake Wakatipu, during last November, a
heavy rainfall was experienced, which, together with the melted
snow on the main ranges, caused a rapid rise in the level of the
lake. On Saturday morning, the 17th November, the rain-guage at
Queenstown registered .66 of an inch, which fell during the
previous night; and on Sunday morning an additional 1.61,
making 2.27 inches during forty-eight hours. The rain being
from the north-west melted the snow with great rapidity,
causing an immense rush of water into the lake, the level of
which rose over two feet in the two days.

While watching the water rising on the morning of the 18th, I
observed that a mark which I had placed on the shore became
rapidly covered and shortly afterwards exposed again, the surface
of the lake being at the time perfectly calm, not a ripple
ruffling it.

As I found it difficult to account for this, I made more
careful observations for upwards of an hour, the result of which
was that I ascertained there was a rise and fall of three inches
in the level of the water at intervals of five minutes, which
was maintained with perfect regularity. This rise and fall was
extremely gradual, so that it was quite imperceptible on the
smooth surface. After 1pm a breeze sprang up, preventing a
further continuance of my observations. I was unable at the
time to account for this disturbance satisfactorily, but was
inclined to attribute it to a slight earthquake, possibly too
faint to be noticed.

In conversation with Mr WORTHINGTON, the Meteorological Observer,
the next morning, I mentioned what I had remarked. He informed
me that he had himself noticed the same rise and fall on a
larger scale, after one of the heaviest floods experienced;
consequently it at once pointed to the floods being in some
manner the cause, though at first sight it seemed impossible
for any flood to have such an effect on a body of water nearly
fifty miles in length and of great depth.