Lake Disappear

By April 7, 2016 No Comments

Te Mata farmer Andrew Buchanan sometimes sees a beautiful” lake on his 1800-acre sheep and beef property — and other times doesn’t.

It’s not that he’s delusional or has poor eyesight:  Lake Disappear, as it’s aptly called, comes and goes every year depending on the rainfall.

“If we have four or five inches of rain tonight, for instance, it would start it off (filling up again),” Andrew told the Chronicle last Sunday.

The lake forms when there’s more water than can drain out of a sinkhole in its southwest corner, and for much of the year it’s a “substantial” two-kilometre long stretch — up to 15 metres deep — on which Andrew and his family have in the past enjoyed jet-boating and sailing.

“I find it beautiful,” says Andrew of the now-you-see-it, now-you-don’t lake. “And it’s good for duck-shooting too.”

The lake is just over 20 km from Raglan and four kilometres beyond Bridal Veil Falls. The south end can be seen from Kawhia Road and the north end — when it is full — from the point at the end of Plateau Road on the Pipiwharauroa Trail, which climbs from near the Bridal Veil Falls up to the Te Uku wind farm.

And though described by Wikipedia as “intermittent”, the lake can remain sometimes for 12 months, Andrew’s been told by a local. “But it’s mostly gone by January,” he reckons.

Andrew says the land agent who sold him the property 20-odd years ago made sure he pointed out the then dry alluvial flats that would fill up during prolonged heavy rain. “So I couldn’t sue him for the loss of land,” he jokes.

Longtime local Sheryl Ker — who these days lives in Bankart Street — also knows all about the disappearing lake, one which coincidentally she recently revisited with the weekly walking group the Raglan Ramblers.

“It’s amazing!” she says of the phenomenon. Sheryl and her four siblings grew up there, the land farmed first by her grandparents, then her parents and finally by her brother Ian White before being sold to a neighbour and then on to Andrew.

Sheryl remembers geologists coming to the family farm to see for themselves the area known as the Pakihi Valley which fills up and drains through the limestone sinkhole.

She remembers eeling with her brothers and sisters in the creek there and loving it, but says that for safety reasons they were “not allowed to go to the hole” near the roadside. “It’s a big hole and the water whirls around like when a plug’s pulled out of a sink.”

The water then goes underground and re-emerges one kilometre on – on Giles Lusty’s farm – where it joins Te Maari Stream and runs into Aotea Harbour.

Wikipedia explains that the wetland-cum-lake was formed about two million years ago when lava and ash came from a vent on Whatipu, just over a kilometre away, and blocked the Pakihi Valley. The Pakihi Stream found its way underneath the large enclosed basin, but cannot drain fast enough in wet weather so the hollow fills up and becomes a lake.

True to its name, if there has been little rain the lake drains away and simply disappears.

As regular mid-week Rambler John Lawson observes: “It’s unique … there’s not too many areas like it around the world.”

A similar phenomenon happens with a placid mountain lake in central Oregon in the United States. It similarly lives up to its name, Lost Lake, by draining away down a lava tube each spring only to reappear on schedule with the onset of winter.

Edith Symes