Stillwater · Alluvial · Isère / Nord-Isère (Trept), FR

Domaine des 3 Lacs du Soleil

Domaine des 3 Lacs du Soleil terrain map
Fair · Rainbow
Medium nymphs · 14–16
New ruleReported 20 Aug 2026

Severe drought restrictions (alerte renforcée) in force

A préfectoral drought order places this catchment's surface water at alerte renforcée, the second-highest of France's four restriction tiers. Fishing itself is not named in the order, but flows are low and water-use restrictions are in force. Zone: Bourbre (dépt 38).

Arrêté préfectoral n°37806 ↗

Temporary notices from official orders and recent fishery reports — they clear automatically once out of date. Always confirm locally before travelling.

A respectable few hours, if you choose your moments
Water temperature is the limiting factor today, not the wave. Fish dawn or dusk if you go at all, and handle everything with extra care.
46% confidence
limited data

Domaine des 3 Lacs du Soleil is often best in spring through autumn.

What moved it
  • WindSE 14 km/hGentle breeze
Today's fly
MN
Medium nymphs14–16
Search the runs and pockets, dead-drift near the bottom.
Conditions on the water
Estimate
Wind
Gentle breeze
SE 14 km/h
N
SE
from the south-east
Wave20 cm ripple
Water temp22.3°C
Air temp23°C
CloudBroken
Pressure1016 hPa
Rain · recent0.0 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

How to fish it · for Rainbow
When
March–May and September–October
Where
Start with Medium nymphs (12-14) on a slow, natural presentation — check locally for the preferred method. Early in the day, try buzzers on a slow figure-of-eight or a booby on a fast-sink line near the bottom. Rainbows respond to more active retrieves — try short strips between pauses.
The plan
Plan A

Start with Medium nymphs (12-14) on a slow, natural presentation — check locally for the preferred method. Early in the day, try buzzers on a slow figure-of-eight or a booby on a fast-sink line near the bottom. Rainbows respond to more active retrieves — try short strips between pauses.

Plan B

Fish early and late, try deeper during the heat of the day with a fast-sinking line.

Watch for

Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.

Bank

Bank-only venue. Fish from accessible margins, points, weed edges, and inflows.

Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 5 with Pro.

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Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2
Reservoir BuzzerHatch
2
3
3
3
3
3
2
Lake OliveHatch
2
3
3
3
3
3
2
Silverhorns & LonghornsHatch
1
2
2
2
1

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Rainbow fly box
MN
Medium nymphsTop
14–16 · Nymph
Search the runs and pockets, dead-drift near the bottom.
DR
dries
12–16 · Fly
A dependable searching pattern for these waters.
BU
buzzers
10–14 · Buzzer
Static or slow on a long leader — the staple stillwater chironomid.
ST
streamers
8–10 · Streamer
Strip it for fish chasing fry or in coloured water.
Permits & access
Permit required — see local rules.
  • Commercial fly-only on the Grand Lac (the other lakes are bait/coarse only)
  • Day tickets required
  • Black bass and perch no-kill.
What's coming
Plan ahead
5-day outlook
Condition match
64%
Cloud100%
Wind65%
Temp25%

A reasonable day here, though temperature isn't quite in the sweet spot.

Cooler water nearby · 3
Water here around 22°C — probably warm enough to stress Rainbow . These are likely cooler.
Chaley Lake
33 km
~15°C
Brown trout · Rainbow trout
Lac d'Aiguebelette
38 km
~20°C
Brown trout · Char
Lac du Bourget
40 km
~22°C
Brown trout · Char
Why this score
  • Cloud cover (cloud) suits the fishery well.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout Year-round → Year-round
Related guides
Small Stillwater Playbookstillwater tacticsThermal Layers & Troutreading depth and temperaturePyrenees PlaybookFrench rivers
Booking & contacts