The Domaine des 3 Lacs du Soleil is a private three-lake complex at Trept in the Nord-Isère, about an hour from Lyon, and the Grand Lac is the fly-only reservoir — the other two waters are for bait and coarse fishing and are not what a fly angler comes here for. The Grand Lac is stocked with rainbow trout as the main target, with perch and black bass both present and both managed as no-kill, which is the sort of mature policy that used to be unheard of in French commercial fisheries and is now slowly becoming standard at the better venues. The water is alluvial and warms up in summer more than an upland reservoir does, so the early season (March–May) and the autumn shoulder (September–October) are the productive windows. This is the closest serious fly-only commercial fishery to Lyon and it functions as the Rhône-Alpes equivalent of Coyolles: your reliable weekend casting venue when the rivers are out of shape.
Good late spring conditions for Domaine des 3 Lacs du Soleil
Useful ripple, fishable wave. Worth a session if the wind holds.
Conditions are not ideal but fishable at Domaine des 3 Lacs du Soleil. Flat calm means fish may be spookier — longer leaders and subtler flies will help.
Conditions on the water
Some readings unavailable — check directly before fishing.
The brief
The plan
Start with Medium nymphs (12-14) on a As per local method. If that does not produce, switch depth or speed before changing the pattern entirely.
If fish refuse on top, drop to a buzzer under an indicator at different depths.
Keep an eye on changing conditions — wind shifts and cloud breaks can trigger short feeding spells.
Bank fishing near inflows, dam walls, and weed beds. Move to find feeding fish.
What's on, when
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Top pattern + the box
Why today scores what it does
- late spring conditions with clear skies and calm wind.
Precipitation
Who this water suits
Domaine des 3 Lacs du Soleil, on the water
Field guide · contributor-editedWhat this water is
The Domaine des 3 Lacs du Soleil is a private three-lake complex at Trept in the Nord-Isère, about an hour from Lyon, and the Grand Lac is the fly-only reservoir — the other two waters are for bait and coarse fishing and are not what a fly angler comes here for. The Grand Lac is stocked with rainbow trout as the main target, with perch and black bass both present and both managed as no-kill, which is the sort of mature policy that used to be unheard of in French commercial fisheries and is now slowly becoming standard at the better venues. The water is alluvial and warms up in summer more than an upland reservoir does, so the early season (March–May) and the autumn shoulder (September–October) are the productive windows. This is the closest serious fly-only commercial fishery to Lyon and it functions as the Rhône-Alpes equivalent of Coyolles: your reliable weekend casting venue when the rivers are out of shape.
- Fishery
- Alluvial
How to get to the water
Where the rules change
- TroutYear-round → Year-round
Licences, sorteo, the rules
- Commercial fly-only on the Grand Lac (the other lakes are bait/coarse only)
- Day tickets required
- Black bass and perch no-kill.
Domaine des 3 Lacs du Soleil
The Domaine des 3 Lacs du Soleil is a private three-lake complex at Trept in the Nord-Isère, about an hour from Lyon, and the Grand Lac is the fly-only reservoir — the other two waters are for bait and coarse fishing and are not what a fly angler comes here for.
Good late spring conditions for Domaine des 3 Lacs du Soleil
Useful ripple, fishable wave. Worth a session if the wind holds.
Conditions are not ideal but fishable at Domaine des 3 Lacs du Soleil. Flat calm means fish may be spookier — longer leaders and subtler flies will help.
Some readings unavailable — check directly before fishing.
A reasonable day here, though cloud isn't quite in the sweet spot.
Start with Medium nymphs (12-14) on a As per local method. If that does not produce, switch depth or speed before changing the pattern entirely.
If fish refuse on top, drop to a buzzer under an indicator at different depths.
Keep an eye on changing conditions — wind shifts and cloud breaks can trigger short feeding spells.
Bank fishing near inflows, dam walls, and weed beds. Move to find feeding fish.
- late spring conditions with clear skies and calm wind.
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
- Commercial fly-only on the Grand Lac (the other lakes are bait/coarse only)
- Day tickets required
- Black bass and perch no-kill.
The Domaine des 3 Lacs du Soleil is a private three-lake complex at Trept in the Nord-Isère, about an hour from Lyon, and the Grand Lac is the fly-only reservoir — the other two waters are for bait and coarse fishing and are not what a fly angler comes here for. The Grand Lac is stocked with rainbow trout as the main target, with perch and black bass both present and both managed as no-kill, which is the sort of mature policy that used to be unheard of in French commercial fisheries and is now slowly becoming standard at the better venues. The water is alluvial and warms up in summer more than an upland reservoir does, so the early season (March–May) and the autumn shoulder (September–October) are the productive windows. This is the closest serious fly-only commercial fishery to Lyon and it functions as the Rhône-Alpes equivalent of Coyolles: your reliable weekend casting venue when the rivers are out of shape.
- Fishery
- Alluvial
- TroutYear-round → Year-round
The Domaine des 3 Lacs du Soleil is a private three-lake complex at Trept in the Nord-Isère, about an hour from Lyon, and the Grand Lac is the fly-only reservoir — the other two waters are for bait and coarse fishing and are not what a fly angler comes here for. The Grand Lac is stocked with rainbow trout as the main target, with perch and black bass both present and both managed as no-kill, which is the sort of mature policy that used to be unheard of in French commercial fisheries and is now slowly becoming standard at the better venues. The water is alluvial and warms up in summer more than an upland reservoir does, so the early season (March–May) and the autumn shoulder (September–October) are the productive windows. This is the closest serious fly-only commercial fishery to Lyon and it functions as the Rhône-Alpes equivalent of Coyolles: your reliable weekend casting venue when the rivers are out of shape.