Disappearing Tarn and somewhere else

On the southern slopes of Mt Wellington, about 4km from The Springs, there is one of the mountain’s more famous features: the aptly named Disappearing Tarn. It lies — when it is there at all — in a curious depression in one of the bigger “potato fields”: a large area of tumbled dolerite rocks and boulders that resembles nothing so much as a turned over field of spuds, only with no soil and with gargantuan spuds. Most of the time the hollow is empty, but every so often after heavy rains and snowfall it fills with clear water only to drain away over the next few days or so.

My brother has never seen the place in its “Appearing Tarn” form and so he and I decided to take advantage of the Show Day holiday and chance a visit today.  The signs were good as we set off along Milles Track, with the path muddy and small creeks tumbling over, under and alongside it. The spring rain was encouraging growth and greening the moss, and the Richea dracophylla was in flower.

The track became rougher as we headed south and then west, and then we came across the potato field (in fact, there are others on the way in, but this one is quite large and has very little growing on it). Some of the boulders in the photo below would be 1-2m (3-6ft) in diameter; very few of them are pick-up-and-carry-able.

We were pleased to see some water in the hollow, although we have been led to understand that it was deeper than this — even swimmable (by foolhardy souls) — a few weeks ago. The water is so clear but it takes on a blue-green colour. The day was overcast and dull, and so all the photographs turned out flat and muted, so it is hard to give you a real sense of the place.

The shot below is from what was probably my most recent previous visit, which was just over 30 years ago. I’ve tried to do a forensic analysis to work out how much deeper it was on that occasion compared to today’s rather shallower Half-Disappeared Tarn, but the angles are wrong and although the boulders are unlikely to have moved, I think the bush has done quite a lot of changing.

There were some lovely little ferns tucked in among the rocks, the native pepper (Drimys lanceolata) was in flower (and if I have seen it in flower before I don’t think I’ve photographed it before), and the backdrop of trees made a contrast to the desolate boulder field. Finally, on our return trip, we spotted a piece of aptly named “Old man’s beard” lichen.

After dropping off my brother, I picked up my parents to continue my determination to have a proper day off. We went for a drive to the Allens Rivulet area, and found one end of the Kaoota Tramway track, which Dad and I have agreed to walk one summer afternoon/evening. Today, however, we just explored the very beginning, with lichen on fence rails, fern croziers doing crozy things, and mossy carpet beneath the trees.