Imagery: Esri, Vantor, Earthstar Geographics

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Penstock Lagoon

Stillwater

1.47 km²

Water area

Species recorded

142

Stocking releases

A small, shallow, fly-only premium fishery on the Central Plateau — a square kilometre and a half of weed beds that grow mayfly by the million, wild browns and stocked rainbows, sight-fishing the western margins early, duns from November, wet-fly teams from a drifting boat all season, and fifteen years of IFS stocking drawn on the page.

Penstock Lagoon began life in 1916 as the storage and intake for the Waddamana power station, and when the station was decommissioned the lagoon stayed, a square kilometre and a half of shallow highland water over weed beds so rich that the mayfly hatches off them are the reason the lake is famous. Inland Fisheries Service manages it as a fly-fishing-only premium fishery, with a high minimum size and a small bag to match, and because spawning is limited here it tops up both the browns and the rainbows with regular stocking; the record on this page runs from 2010 and stands at well over a quarter of a million fish. The fishing follows the water. Early in the season, with the level high, the browns sight-fish in the shallow weedy margins of the western shore. Through spring they chase galaxias along the rocky shores and a wet fly along the rocks takes them. From November the mayfly and caddis come off the weed in numbers and the fish switch onto them for the rest of the season, with dries and dark nymphs through the hatches. And all season a team of wets from a drifting boat is productive, which is how much of Penstock is fished. It is small, shallow, full of submerged timber, and its weed beds are fragile, so the boating rules are strict and worth reading. Its level peaks in spring and holds steady through the year, and Hydro Tasmania and IFS manage it between them for the fishery rather than for power.

Target species

Brown Trout

Rainbow Trout

No live gauge

There’s no gauge on this water. Check recent trip reports.

Season

Regulations

Driving directions

Water and habitat

A square kilometre and a half of shallow water on the plateau off Waddamana Road, made in 1916 as the intake for the Waddamana power station and kept as a fishery since the station closed. Weed beds over most of it, submerged timber and rocks, a shoreline that runs from weedy marsh to forested rocky bank, and a level that peaks in spring and stays fairly stable the rest of the year under Hydro Tasmania’s management. The weed is the fishery: it grows the mayfly and caddis in numbers that the plateau’s other waters do not match for their size, and it is fragile, which is why the boating rules are what they are. Satellite observation of its wet surface goes back to 1987.

Fish and forage

Brown trout and rainbow trout, wild fish topped up by IFS because natural spawning is limited. The stocking timeline on this page runs from 2010 and holds around a hundred and forty thousand rainbows and a hundred and thirty thousand browns across more than a hundred and forty releases, which is a premium fishery being kept full rather than a put-and-take lake being restocked; the two-fish bag and high minimum size say the same thing.

The mayfly is the forage of the year from November on, with caddis beside it, both hatching off the weed beds. Galaxias along the rocky shores in spring, damsels through summer, and the small stuff of a weedy lagoon between hatches.

Observed

Stocked

Brown Trout

Salmo trutta

Shannon Paragalaxias

Paragalaxias dissimilis

When to fish it

Early season, with the level high, is sight-fishing to browns in the shallow weedy margins of the western shore. Spring is wets along the rocky shores where the trout chase galaxias. From November the mayfly and caddis start and dry-fly fishing comes into play, and IFS says the fish stay on them for the rest of the season. Throughout, a team of wets from a drifting boat is productive. On a dull, humid day in the hatch months, be here or at Arthurs; on a bright windy one, the western shore and a wet fly. The lagoon closes for the winter; check the current IFS Fishing Code for the date before you plan a late trip.

THE YEAR ON THIS WATER

Sight-fishing the western margins

Fly · Aug–Oct

Early season, water high, browns in the shallow weedy margins of the western shore. Look, then cast.

Galaxias on the rocky shores

Food · Sep–Nov

Spring. Trout chase galaxias along the rocky shores and a wet fly or small streamer is the answer.

Mayfly and caddis

Food · Nov–Apr

From November the weed beds hatch mayfly and caddis in numbers, and the fish switch onto them for the rest of the season.

Wet-fly teams from a drifting boat

Fly · Aug–Apr

Productive all season. Damsels and Woolly Buggers when nothing shows, dark mayfly nymphs and dries through the hatches.

How to fish it

Early, walk the western margin and look before you cast; a small Pheasant Tail or an unweighted nymph ahead of a browsing brown. Along the rocky shores in spring, a Woolly Bugger or a small streamer stripped back to imitate a galaxias. Through the hatches, a dark mayfly nymph or a Klinkhammer as the fish bulge, and a parachute Adams or a highland dun pattern once they are taking duns on top. From a drifting boat, a team of wets on a floating or intermediate line with a damsel or a Bugger at the point, all season. A five or six weight and a long leader; the fish here have been fished for.

Access and safety

Off Waddamana Road, with the single ramp at the northern end of the western shore by the canal, a landing beside it to help launching and boarding, and signed parking a short walk from the water. A foot-access easement runs around the eastern shore ten metres above full supply level. Two designated campsites on the western shore; camping or caravanning is capped at fourteen days. Named starting points include both dam walls, Beginners Bay and Break O’Day shore.

Boating rules protect the weed beds and the boats. A marked twenty-five-metre corridor guides petrol-powered boats from the ramp end down to the Lilly Pond at the southern end; outside it, manual or electric propulsion; Beginners Bay is manual only; a five-knot limit applies over the whole lagoon and trolling is not permitted. The lagoon is shallow with submerged timber and rocks. The two inlet canals above their marked posts are closed to fishing.

Regulations

Inland Fisheries Service manages Penstock Lagoon as a fly-fishing-only premium fishery. It states a high minimum size, a small bag with a cap on larger fish within it, a season that opens and closes on set dates each year, and a standing closure on the two inlet canals above their posts. Trolling is not permitted and a five-knot limit applies. An inland angling licence is required.

Take the numbers and the dates from the current Tasmanian Inland Fishing Code and the IFS A to Z page for the lagoon before you fish. They move, so read them there on the day you go.

Access restricted

TAS

A low wake speed limit of under 5 knots applies across the whole of Penstock Lagoon in Tasmania, to avoid damage to the lagoon's fragile weed-bed habitats.

Tasmanian Government (Inland Fisheries Service), under the Inland Fisheries Act 1995 and Inland Fisheries Regulations 2019

Read the rule at source ↗

Prohibited

TAS

Trolling from a boat is not permitted at Penstock Lagoon or Little Pine Lagoon in Tasmania.

Tasmanian Government (Inland Fisheries Service), under the Inland Fisheries Act 1995 and Inland Fisheries Regulations 2019

Read the rule at source ↗