Lake Eucumbene Falling

All is not lost when you find Eucumbene dropping, writes Steve.

It’s a week before Christmas, still early summer, when the fabric of the cool evening air is rent by a tormented curse. Black ducks take flight, the evening chatter of frogs and crickets is momentarily silenced. A man clad in khaki waders with rolled-up shirtsleeves ready for action, shakes his fist at the water. His companion, new to Lake Eucumbene and taken aback by the outburst, calls out, “What’s wrong?” The reply is almost spat back. “The bloody lake is falling!”

The sight of a falling lake can strike dread into the heart of the toughest soul. For weeks, you’ve dreamt of this moment: the trip, the check-in at the campsite, the drive to the lake for the first evening fish (arriving just a bit too early) building the anticipation to a crescendo… only to have the bubble explode at the sight of a wide, wet, muddy scar along the shore. Okay, you didn’t check the Snowy Hydro lake levels calculator (or read my blogs) and that may have been an oversight, but surely you were due for a bit of luck? After all, you were coming anyway, weren’t you? It’s the only week you could get leave.

However, all is not lost. Things mightn’t be as bleak as they seem right now. Don’t worry, you’re still going to catch fish.

Eucumbene's rise and fall is marked by sediment layers like tree rings. It's doing one as often as the other, so it makes sense to be tactically prepared.

Eucumbene’s rise and fall is marked by sediment layers like tree rings. It’s doing one as often as the other, so it makes sense to be tactically prepared.

Carp Pond Analogy

There’s little written about the actual ecosystems of our hydro lakes and how they work. In Europe, I once met a carp farmer who managed his lakes like a garden. Each season he drained them, limed them, fertilised them, placed bales of hay to rot and generate nutrients to encourage bugs, and then flooded them. After a short period of stabilisation, the carp were put in and thrived in the man-made soup. He would add hay bales through the growing season to keep the stew bubbling. He had a swampy shallow end of the lake, and a deeper clean end.

On a much-diluted scale (there’s no carp farmer intervening!) this is what happens naturally when Lake Eucumbene rises substantially, complete with the swampy shallow end – Providence and shallow bays like Yens and Buckenderra – and the deep expanses of blue water beyond. No wonder we like a rising lake! When Eucumbene retreats, the ‘pond’ is partly drained and much of the food-chain-feeding vegetation is used up or left behind, high and dry.

Why They Drop?

Many of our greatest Australian trout lakes are hydro lakes, built to generate electricity and divert water for a range of reasons. Fish habitat and the broader aquatic ecosystem comes a distant second to the needs of power generation and moving water around. The lake operators certainly don’t have an abiding interest in fish habitat. Only we, the trout fishers, really care. A minority group. With no say, for example, against the might of the power consumer. A heatwave in Adelaide, a cold snap in Melbourne and on go the reverse cycle air conditioners and someone somewhere, sitting in front of a computer, watching a big glass gauge – or maybe just getting an SMS – identifies the spike in power demand, pulls a lever or presses a button, sends an email or clicks on a link or an icon. The turbines start spinning faster, and the water level drops.

Or that’s what we imagine happens. The actual sequence of events is well hidden under a cloak of top secret commercial-in-confidence bureaucratic mumbo-jumbo. Really?? Note to Snowy Hydro management: we do understand you need to drop your lakes, but we don’t understand why you can’t tell us when you’re about to do it! We know your operational staff have an app that tells them exactly what’s going on and where, and we don’t understand why we can’t have some of that information too?

Lake Eucumbene

Lake Eucumbene is my falling lake focus, because I fish it so often, and it’s my favourite lake in the world. There isn’t big agriculture churning nutrients into the system, just low-intensity grazing land and beautiful pristine national park for a catchment. So from a productivity point-of-view, it’s no European carp pond.

Eucumbene may not be an especially fertile water, but excellent water quality and water temperatures ensure it produces good trout; even when levels are falling.

Eucumbene may not be an especially fertile water, but excellent water quality and trout-friendly water temperatures ensure it produces good trout; even when levels are falling.

On the plus side, when the wind stops blowing, the water quickly settles to tropical island clarity and the lake never suffers from unfishable (even lethal) algal blooms. And its enormous thermal mass ensures that, while surface and near-to-shore water temperatures can vary between 5C and 25C, the deeper water remains at ideal trout temperatures throughout the year.

Trout and a Falling Lake

So why do we hate a falling lake? Well, because trout mostly hate a falling lake! The general view is that natural selection has sorted out the trout that evolved to survive the risk of stranding by seeking out deeper water.
What happens to the trout in a falling lake, where do they go, and how do we catch them? I suppose the first thing our fist-shaking mate at the start of the story should note is, there are no fewer fish today than there were last week before the lake started to drop. We just need to find them and then work out how to catch them.

Shores which slope into deep water but not far from the normally productive shallows, are a good falling lake option for shore-based anglers. (Note the plume of wave washed dirt water, which the trout will cruise the edge of.)

Shores which slope into deep water but not far from the normally productive shallows, are a good falling lake option for shore-based anglers. (Note the plume of wave-generated dirty water, which the trout will cruise the edge of.)

We’ve got an extra piece of information to factor into the equation, specifically that the fish have switched to safety mode. They are as interested in pure survival as feeding, and they are moderately stressed.

The Stages of Stress

When conditions are ideal – like when a lake is rising for example – watching a trout that hasn’t seen you, brings to mind the saying, ‘dance like nobody’s watching.’ At these times, trout can appear almost playful, happily chasing anything that seems to interest them; hunting, nosing into weeds and turning over gravel and small rocks, chasing away certain fish that come into their patch, drifting up to take a surface morsel… I’ve watched countless such fish chase a fly right into the shallows, get really agitated when the fly is lifted out of the water, and then dart about trying to find where it went. Occasionally, these trout nail the fly brutally as soon as I drop it back onto the water.

The stage down from this might be described as, ‘dance like somebody is watching.’ The trout sense something that makes them uneasy – an unusual shadow, shape, vibration… A vague threat. Their body language changes. They visibly stiffen; they might even merge into the depths, hug the bottom, slide under an undercut bank and gently disappear. A trout that would nail a well presented dry a moment before is now uncatchable.

Or is it? Deep nymphing a stretch of river just worked by a dry fly fisher, can often result in several fish caught from the supposedly ‘spooked’ water. The skilled nympher is focused on getting the flies down in the water column; right in front of trout that, since being fished over, are no longer out and about. I even think back to worm fishing off a bridge as a child, watching a school of small trout evaporate in response to my outline, yet placing the wriggling bait right against a rock – and seeing a fish dart out and grab it.

Cold, windy, low, falling lake… but the trout still have to eat eventually, and that’s still a lovely fish! You don’t have to depend on perfect conditions to have success at Eucumbene.

The final state is total flight – the trout just bolt, with the goal of putting as much distance between them and danger as possible.

When we’re talking about trout in a falling lake, it’s the middle state that is typical. The fish are still willing to feed, but they’re operating in a generally cautious state.

Less Blunder, More Blending
So let’s assume my hypothesis is correct; that the residents in our falling Eucumbene are alert but not alarmed. How are we going to approach the problem? Of course, no one reading this is one of those water buffalo we occasionally see storming up and down the shoreline, splashing through ankle-deep shallows or clunking about in the boat. I don’t really need to point out that trout, already mildly stressed and with a heightened alert response, are easier to spook.
Instead, we’re creeping around, trying to keep a low profile, moving as noiselessly as possible, avoiding bow-waves, backlighting and shadows on the water.

Finding the Fish
The next question is where the fish are likely to be and how we are going to catch them? Our targets are not going to be cruising the shallows unless low light and a very decent food reward makes it worthwhile to their nervous dispositions. And even out in the deeper, safer water, they may not be feeding actively, or even at all. I keep the occasional Eucumbene trout and when I’ve cleaned those caught when the lake has been falling steadily for a few weeks, often they have absolutely nothing in their stomachs.

When the water is stable or rising, some of the best places for flyfishing on Lake Eucumbene are the generally shallow areas adjacent to gently sloping shores; and the flood plains of ephemeral creeks that concentrate the scarce nutrient inflows.

However, when the lake is falling, the shallows aren’t your first target. I’m not saying ignore them entirely, but they’re not your priority. Think back to that nymph fisher on the river. The trout are sitting in deeper water where they feel safe, but they haven’t gone too far from their usual hotspots.

When the lake is falling, stay away from the muddy shores.

When the lake is falling, stay away from the muddy shores.

So look for deeper channels, slightly steeper banks, structure, and drop offs near the places you might normally fish. And look for areas that aren’t soft mud! Seriously, wading these shores is no fun, and at times is downright dangerous. Sooner or later you’re going to end up thigh deep in trench mud, or slipping and landing on your backside. Find the steeper shorelines that merge into the clay or gravelly banks. You’ll be able to stand upright, and fish into deeper water.

Getting Down

Now you have to get the flies down to the trout. There are two broad options. The first is to fish a sinking line, the second is to fish with some weight in your flies. Or both.

If you’re confident about the depth you want to fish, or if you really want to fish deep (and I mean more than 3 or 4 metres) a sinking line is the best option. Using a sinking line means you can fish lightly weighted flies that can be stopped without sinking like a stone – maybe that makes them look more natural. On the downside, you pretty much need to keep the fly moving once you’ve reached your target depth or you’ll be dragging the bottom. Sinking lines are a whole masterclass of discussion, but in short there are lines that sink very slowly, right through to lines that go down like a rock. If you want to carry just one, maybe a medium sink rate of 2 to 3 inches per second is a good. (See FlyStream Facts at the end.)

Perhaps surprisingly, a floating line can work too. To get down to the trout with a floater, you need to use weighted flies; more weight than normal. Either use tungsten beads or try your usual flies with split shot added to the leader. Regarding leaders, depending on what length you normally use, think about adding another metre, or even a bit more. The leaders which will sink best are level rather than tapered, and fluorocarbon rather than monofilament. Maybe start with a leader 3 metres long, and work up to 4.5 metres if you’re not catching fish. Stick to what you can comfortably work with – and if long leaders and heavy flies are a real problem for your casting, then go back to a sinking line and shorter leaders.

With a floating line and a bit of weight, we have the option of fishing flies quite deep and more or less static, especially if we use an indicator. Eucumbene trout love a fly that’s static or barely moving. Everyone has a story about a mate who tucks his rod under his arm to apply more sunscreen or put on gloves, only to hook the solitary fish of the session. One good fishing friend, aka ‘The Heron’ recovers his fly once, to my four times – and seems to catch more fish. I’m just not that patient!

Slow, patient retrieves are an excellent option when the lake is falling and the trout - even rainbows like this one - are less active and aggressive.

Deep, slow, patient retrieves are an excellent option when Eucumbene is falling and the trout – even rainbows like this one – are less active and aggressive.

Falling Flies
As for flies, there’s no better time to hang a small weighted nymph, size 14 to 16, or to slow strip a small Woolly Bugger, size 12 to 14, in fiery brown, black and green. A selection of small nymphs should include some with and without bead beads. And there is no way I’d be out on a falling Eucumbene without a Scintilla Stick Caddis.

Even though I’m usually a big fan of bling and flash, in these conditions I always seem to catch more with less. About the most bling I’d go for is a brass bead on an olive-green nymph – which would be my go-to deep water fly to get started. And actually, I often fish two flies deep; a nymph on the point, and a Woolly Bugger on the dropper about 60 centimetres up. If I was only fishing one fly, I would alternate between different nymphs and Woolly Buggers. I would strip a few flies quickly, but mostly I would fish deep and slow.

A beauty on a small black Woolly Bugger, fished deep and slow near the exposed yabby beds at Frying Pan.

And Finally…

A few points to finish with. First, a boat is a real bonus when Lake Eucumbene is falling – obviously for fishing from, but also to check out more spots quickly, and to use the sounder to find fish in deeper water. Secondly, yabby feeders do well when lake levels rise and fall. Lake Eucumbene has immense yabby beds and every time the level changes, the yabbies move around. When they’re migrating, they’re more vulnerable to the trout.

Finally, if you’re a regular, then make a mental map of the characteristics of the lake bed that emerge when the lake is falling; or better still, take some pictures. When the lake rises and all is right with the world once again, it will be handy to know where drop-offs, flooded gullies, soaks, yabby beds, reefs etc are, hidden just below the surface.

When Eucumbene is falling, take advantage of the chance to note he many features and lake contours which may be submerged again next time you visit.

When Eucumbene is falling, take advantage of the opportunity to note the many features and lake contours – which may be submerged again next time you visit.

FlyStream Facts – Sinking Lines
Sinking lines are a whole subject in themselves, but very briefly and simply, sinking lines are rated from 1 to 6, which corresponds to sink rate in inches per second. For example, for a class 2, think 2 inches per second (+/-1 inch) as a very rough guide. I’m always in a bit of a hurry, so I don’t like waiting much more than 30 seconds before getting the urge to twitch my fly. And perhaps not coincidentally, a class 2 line will be at about 2 metres in 30 seconds.
To complicate things, on hot, dry windless days sinking lines can take a few seconds to get under the surface – sometimes they simply refuse! And where the water is moving along a shore on a windy day, or if you’re casting across even a modest inflow from the river, tension on the line puts a belly in it which slows the sink rate and makes it difficult to stay in touch with the fly. Allow for these factors in your sinking line calculations.