Spate · Granite · West / South Mayo, IE

Carrowniskey

Carrowniskey terrain map

A short south Mayo spate river running off the slopes of Croagh Patrick and the Sheeffry Hills to the sea near Louisburgh.

Prime · Atlantic Salmon
Cascade · 8-10
Primelive now
Prime conditions — go now
River steady at a fishable height. Settled and taking. Work it methodically.
85% confidence
What moved it
  • LevelProxyvia Erriff
  • Water temp12.8°C
  • ClarityClear
Today's fly
Cascade
Cascade8-10
Regional salmon default — river-specific evidence is thin.
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Erriff
Water temp12.8°C
ClarityClear
Weather18°C
WindSE 54 km/h
Pressure987 hPa
Rain · recent13.2 mm
Rain · ahead10.1 mm

No gauge on this water — conditions are inferred from Erriff. The trend transfers, the absolute level does not.

Water temperature for Atlantic Salmon
Ideal
13°C est.ideal 10–16°C
0°14°28°
How to fish it · for Atlantic Salmon
When
Morning into early afternoon.
Where
Pool tails, steadier runs, and any water with pace.
Method
Fish a sensible line-and-fly combination for the height and pace of water.
Kit
13 ft #8/9 double-hander in spate, 10 ft #8 single in low water. Floating line plus a fast-sink tip. 12–15 lb fluoro tippet.
Why this works
Excellent — water temperature is right today, though river flow could be better.
Likely species
Hatch timeline · todayPeak at 2pm

Hatch predictions

Today's headline hatch shown — see all 12 active hatches hour by hour as a supporter.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds as a supporter.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 as a supporter.

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Evidence
Survey-backed · regionalHigh confidence

Backed by regional invertebrate surveys; no sampling on this exact reach yet.

Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Salmon runRun
1
2
2
2
2
1
Sea trout runRun
1
2
2
1
March BrownHatch
2
3
2
CapererHatch
2
3
3
2
Heather FlyHatch
2
2
Autumn DunHatch
2
3
2

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

Ranked for today
Atlantic Salmon fly box

Connemara/Mayo low water: a lightly-dressed shrimp on a floating line with sink tip, sized down from 8s in cold spring water to 12s and 14s as summer water warms and clears. Where the current runs faster, a slim tube or hairwing swung through tracks better than a shrimp.

Permits & access
Permit required — see local rules.
  • Western district
  • IFI managed in part; part of the river held privately by the Harman family
  • Shrimp (natural and artificial) is prohibited
  • State rod licence required.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
About this water

A short south Mayo spate river running off the slopes of Croagh Patrick and the Sheeffry Hills to the sea near Louisburgh. Part of the Ballinakill coastal district. Sea trout and grilse enter on the summer spates; the river dries to a trickle in July drought. Roonagh Lough, on the system, also offers fishing for both species when conditions allow. Part of the river is held privately by the Harman family; the rest is club and IFI water with day permits available locally. The setting is exceptional — the reek of Croagh Patrick above, Clew Bay below — but the fishing demands water. Given the right conditions, fish move fast through the system and are fresh. A river to visit opportunistically rather than plan a trip around, but one worth knowing for its quality when conditions align. For 2026 this is a catch-and-release fishery under the Wild Salmon & Sea Trout Tagging Scheme — all salmon and grilse must be returned.

Hatches & food

EPA monitoring confirms mayflies, stoneflies, caddis, aquatic diptera and gammarus are present across the Carrowniskey's WFD reaches. This is food-presence evidence from kick sampling only, with no confirmed emergence timing or dependable hatch.

  • Granite
Water quality (WFD)
  • Ecology: Unknown
  • Chemical: Unknown
Why this score · for Atlantic Salmon
  • Temperature10030% weight
  • Flow6025% weight
  • Clarity9520% weight
  • Feeding Time8015% weight
  • Pressure8510% weight
Directions
Seasons & zones
  • Salmon 1 April → 30 SeptemberC&R
  • Sea trout 1 June → 30 September

Sea trout: Variable seasonal (2026)

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