Not a big irrigation lake. A small off-creek storage near Lithgow and Wallerawang, built to feed the Mount Piper and Wallerawang power stations rather than to make a fishery; the creek catchment on its own is not the point, water is moved in, and the lake you fish is a managed pondage. Steep quarried edges, a dam wall you may walk across inside the fence but not fish from, a timbered and grassed shoreline elsewhere, and depth close to the bank. There is no boat to skip the empty water. You walk, you pick a bank, and you fish what you can reach.

Satellite observation shows the dam first filling in the spring of 1992 and sitting near full through most years since, with a long-run average around seven-tenths of its full area because the early years and three deep drawdowns pull it down. In 2017 and again in 2024 the lake fell to under half its area, and in the autumn of 2026 to a small fraction of it, refilling within months each time. When the dam is down the fish are concentrated, the banks you can reach are different, and the edges are mud; when it is full the timber and the grass come to the water.

Rainbow trout and brown trout, stocked every season. NSW DPIRD’s stocking summaries record both released into the dam in each year from 2019 to 2026, rainbows in the larger numbers, and the timeline is drawn on this page. The department manages it as a trophy fishery and says so. That is the authority talking, not a survey count; the fish you catch will tell you more than this page can.

A clear tableland lake grows the small stuff: mayfly and midge over the weed and in the lanes, damsels along the margins, and off the timbered shore the beetles, ants and grasshoppers that a fish tight under the bank is waiting for in a summer afternoon. Yabbies and small fish in the deeper water are what the big browns grow on.

All year, in daylight, under the department’s hours. Nothing here is gauged for anglers, so you are reading the water and the sky for the level rather than a number before you leave.

Warm, still evenings from November to March are when a lake this size shows fish on the top, and the last hour of light is the hour. Midday in summer, look for shade and deeper water along the wall and the quarried banks. If the wind is up, the windward shore is usually the one with food in it. Autumn and winter are the deep, slow months: cold water, fish down the drop-offs, a sinking line and patience, and the big browns of the stories.

You are fishing a small, clear lake from the bank, with no wading and no boat, so the retrieve and the line density are how you get to the fish. A five or six weight is more use than a four in the wind. A floating line for the edges and the evening rise; an intermediate and a fast sinker for the drop-offs. Carry enough leader that the fly can drift without the fly line sitting in the lane.

When fish are on the top, a visible dry is the job: an Adams in the size of the food, or a Klinkhammer for the sippers, drifted without drag along the bank and over any rise you can cover. Beetles, ants and a hopper are the daytime shapes on the timbered shore, and a pale moth at dusk is the hour a lot of people wait for. When the surface is quiet, a Woolly Bugger in olive or black on a sinking line along the drop-offs, retrieved slowly with long pauses, or a slim Pheasant Tail hung under a dry over the weed. Change depth before you change pattern.

This is not a place to spray the gaps. One honest cast along a bank you have approached quietly beats ten from a skyline, and on a shore-only lake the fish are often closer to your feet than to your backing knot.

This sits on private property. NSW DPIRD, anglers and the landholder negotiated access for anglers only, and the landholder can refuse that access at any time. A pin on a map is not permission.

The only entry the department names is the Willow Vale Road car park, then a walk in. No vehicles, motorbikes or pushbikes on the landholder’s country, no camping, no fires, no dogs. You may walk over the dam wall inside the fenced boundaries, giving way to vehicles by moving to the lake side of the road, still inside the fence; fishing from the wall is not permitted. Read the current DPIRD Thompsons Creek Dam page before you leave. The conditions of entry are part of keeping the water open, and they can move.

If something goes wrong, call 000 first. The department’s access page also names a landholder emergency contact; use whatever is printed there on the day, and describe where you are from the signage at the car park. It is a confusing place to pinpoint from a phone, and the quarried banks are steep and slick when the level is down.

NSW DPIRD classifies Thompsons Creek Dam as an artificial fly and lure trout dam under the Central trout-waters guide. It is open to fishing all year under fly-and-lure-only rules, with up to three hooks per line permitted where those hooks are artificial flies or lures. Fishing is shore-based only, and it is permitted only from one hour before sunrise to four hours after sunset. The usual NSW freshwater size, bag and licence rules apply on top.

Do not take bag or size numbers from memory. Check the current NSW freshwater synopsis and the Thompsons Creek Dam access page before you fish.