PENSTOCK LAGOON

For several years now, Penstock has been Tasmania’s most heavily-fished stillwater, and it’s not too hard to see why. Despite the heavy pressure from anglers, this shallow, fertile lake still turns on some excellent fly fishing on the right day.

The trout fishing fortunes of Tasmania’s lakes rise and fall with the vagaries of the island state’s seasons. Changing water levels and boom-to-bust cycles of food abundance impact on the numbers, condition and catch-ability of Tassiw trout. As a result, different waterways have their red-letter years and also their below par ones. Keeping an ear to the fishing grapevine helps visiting anglers stay on top of these shifting patterns, reducing the time spent flogging less productive spots. That can be critically important when you only have a short time to spend on the beautiful Apple Isle.

One waterway whose trout fishing star has been in the ascendancy  for a few years now is shallow Penstock Lagoon, on the Central Highlands, not too far from Arthurs Lake, and only 20 minutes drive from the township of Miena, on the shores of Great Lake.

During a visit to Tasmania one recent spring, Jo and I fished Penstock on several consecutive days, and this lake effectively saved a trip that was plagued by unrelenting gales and otherwise lacklustre fishing. While certainly not sheltered from the incessant south westerly winds that cursed our stay, Penstock offered enough willing fish to help us temporarily forget these trying conditions. We can only imagine what a total delight this little gem must be in less demanding weather!

Penstock Lagoon was constructed in 1916 to supply water to the now decommissioned Waddamana power station. The shallow, man-made lake has been renowned as a first class trout fishing venue ever since.

No longer used for power generation, Penstock’s water levels tend to remain reasonably constant, only fluctuating slowly over time with variations in seasonal rainfall. These relatively static levels tend to promote healthy weed growth and a rich fauna of aquatic insects and small native fish. This helps explain why Penstock has become such a blue-ribbon fly fishery.

With very limited opportunities for resident trout to spawn successfully, Penstock requires regular restocking with both browns and rainbows by Tasmania’s proactive Inland Fisheries Service (IFS). Today, the lake is managed as a fly-only fishery, with a strictly-enforced daily bag limit of three trout per angler and a minimum legal length of 420 mm for those fish. The lagoon is also closed to all fishing from the end of April until the beginning of August, and fishing is not permitted in the adjoining canals upstream of a pair of white posts. (Note that these were the rules at the time of writing. Regulations do change from time to time, so check before you fish! And remember that you’ll need a current Tasmanian fishing licence, unless you fall into one of the exempt categories. Click the Local Regulations tab below for more details.)

This small highland waterway offers a surprising range of angling environments, from shallow, marshy and reed-lined bays (mostly along the western side) to forested, rocky shorelines frequently exposed to energetic wave action (primarily on the eastern edge). All of these banks lie well within reach of walking or wading anglers, and there’s public foot access right around the lake, as well as parking and camping areas along the more easily accessible western side. However, a lot of the most consistent fly fishing actually takes place out in the middle of the lagoon, which is rarely more than a few metres deep and carries luxuriant weed beds that extend almost to the surface in some places.

These open lake waters are best fished from a drifting boat, typically using a drogue or sea anchor to slow and direct the drift. A drogue is almost essential in anything other than very calm conditions, and the best style of drogue for the job is the type commonly used by keen Tasmanian lake fishers, consisting of a rectangle of shade cloth or something similar with chain strung along the bottom edge and pool noodle fixed at the top for floatation. These nifty bits of kit can be deployed on various lengths of rope and angled to quarter across the breeze.

Fishers mostly cast their offerings ahead (downwind) of the drifting vessel, picking up fly line as the boat closes on the fly or flies. “Loch style” fishing with a “team” of up to three flies, each rigged about 1.5 m apart on a long leader, is especially effective here. One of the most exciting options is to rig a buoyant, bushy dry pattern as your uppermost fly, with a weighted nymph at the point (end) of the leader and something like a stick caddis in between. Small, dark flies often seem to work best on Penstock.

When the mayfly duns are hatching in profusion (as they often do from November until March, especially on overcast, breezy days), it pays to revert to a single dry fly on a fairly long, fine tippet and cast this at individual rising fish… There are few more rewarding and exciting ways to catch trout!

While most of the trout in Penstock are fairly modest specimens weighing from 400 g to 1 kg or so, don’t be lulled into a false sense of security. There are also some absolute thumpers in this waterway, and if a 3 kg rainbow inhales your fly, you’ll have a real fight on your hands! Even at their more commonly encountered average weights, Penstock’s fish seem to be especially lively and spirited representatives of their breed.

In addition to the fly-only rules and premium fishery regulations already described for Penstock, some specific boating restrictions also apply to this lake. To begin with, there’s a blanket speed limit of five knots covering the entire lagoon. In addition, a 50 m wide designated boating corridor exists down the centre of the lake, clearly marked with buoys. It’s strongly recommended that all vessels travelling under petrol power confine themselves to this central corridor, switching to electric power, oars or paddles whenever moving outside of the corridor to fish. There’s also a marked area encompassing Beginners’ Bay, adjacent to the famous Lady’s Walk, where no form of motorised propulsion (including electric motors) may be used at any time. Boaters are also encouraged to stay well clear of any wading or walking anglers.

As mentioned, this is a very shallow lake. Great care should be exercised when negotiating the channel from the concrete boat ramp in the north western canal out into the main basin to the start of the boating corridor, especially if water levels are down.

Basic etiquette should also apply at all times. Observe the drift patterns of other vessels and don’t “drop in” ahead of them to fish water they’re obviously intending to work on that drift. Apply a bit of common sense. Although only about 2 km long and well under a kilometre wide, it’s perfectly feasible for a dozen or more small craft to work separate drift lines at any given time without adversely impacting upon each other’s sport.

On its day, Penstock Lagoon can be one of the most delightful and rewarding trout lakes in all of Tasmania’s Central Highlands, and it’s definitely one of the island state’s premier fly fishing spots these days. It’s also one we’ll be factoring into our plans for any future forays across Bass Strait.