• Climbing the hill to the lake. It wasn't this snowy when we started!

  • The true outflow of the lake.

  • Rachel on the lake shore. Sorry, no cute penguins in the background.

  • The watershed. Sadly not in the lake.

  • The lake - an interesting mix of frozen and open water.

  • Loch Nan Eun map.

Bifurcation Lake

The OS map of Glenshee contains the following curiosity:

Loch Nan Eun map.
Loch Nan Eun map.

Yes, a lake (apparently) with two outlets! The Southern one flows into Glenshee and eventually to the sea at Dundee, while the Eastern one flows towards Braemar and eventually to the sea at Aberdeen. Geeky hydrologists (my wife) get excited about this sort of thing because it’s impossible to determine where the watershed is: it’s somewhere in the middle of the lake! So naturally, we had to go and have a look for ourselves.

Happily it was a much better (colder) day than yesterday, when we only managed to brave the horizontal sleet for a couple of hours before retreating to the hotel and spending the afternoon exploring the charms of Blairgowrie. Today started cold and frosty but dry. We headed up the glen from our hotel, before discovering that there was a small problem with our plan: a series of very cold streams to ford. Every time our feet warmed up from one, we seemed to arrive at the next, and in combination with the dusting of snow on the ground, warming up our feet took quite a while!

Climbing the hill to the lake. It wasn't this snowy when we started!
Climbing the hill to the lake. It wasn't this snowy when we started!

After a bit we ended up on a steep wet trail beside the river, and in a driving snowstorm. Visibility was zero in the stronger gusts, but we pressed on regardless, excited (no, not really) by the thought of the hydrological marvel ahead. The snow got deeper, our feet got colder, and the blizzard got worse, but eventually we hauled ourselves up the last slope and reached the edge of the lake, at which point the snow miraculously stopped and we had a break in the cloud with our first view of blue sky all day. Timing!

The lake - an interesting mix of frozen and open water.
The lake - an interesting mix of frozen and open water.
The true outflow of the lake.
The true outflow of the lake.

Since we’d arrived close to the southern outlet, we knew that one flowed in the right direction, so we set off around the edge of the lake to the Eastern outlet. The lake was beautiful, with open water in the centre and ice around the edges except where small streams flowed in. After floundering around in peat hags for a bit, we reached the Eastern shore to discover that sadly there isn’t normally a bifurcation there. The “outlet” was actually an inlet for perhaps 25 metres before turning into a stream flowing in the opposite direction. I suspect the lake would need to be about three metres higher than it was to flow in both directions. What a disappointment! Rachel’s inner hydrologist was inconsolable, but after bribing her with jelly babies we soon continued (it was too cold to hang around).

The watershed. Sadly not in the lake.
The watershed. Sadly not in the lake.
Rachel on the lake shore. Brrr!
Rachel on the lake shore. Sorry, no cute penguins in the background.

The way back mostly involved sliding down the newly fallen snow, and enjoying the view down the valley that came and went as the snow showers blew through. Despite our disappointment, it was a lovely walk with some spectacular views, and a reminder of something we learned from our Estonian friends Juhan and Eneken: There’s no such thing as bad weather, only inappropriate clothing choices!

3 thoughts on “Bifurcation Lake”

  1. I can just about see a smile in Rachel’s eye in the last picture, so no need for penguins. The jelly babies must have done the job because there’s definitely no smile on the second to last picture ๐Ÿ˜‰ .

  2. Made me laugh! ๐Ÿ˜† Hmm, I wonder if I’m a geek? :geek: Oh wait, I already know I’m one of those, but I never thought I’d find hydrology interesting … I wonder if the water level is a little higher when there is no snow? For example, during the monsoon season (i.e. summer) ?

    1. it would take a fair amount of rain to raise the water level by 3 m…. The real question is whether some of the lake water does indeed bifurcate, via a subsurface route beneath and around the lake…I.e. through the groundwater. That still wouldn’t make it a truly bifurcating lake, but it would mean that the water in the lake could reach the sea either in Dundee or Aberdeen, which is cool.

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