Freestone · Mixed Sedimentary · Otago

Pomahaka River

Pomahaka River terrain map

The Pomahaka is one of West Otago's best-kept brown-trout rivers — a friendly Clutha tributary with long glides and runs and a reliable afternoon mayfly hatch, fished much like the Mataura.

Poor · Brown Trout
Hare & Copper Nymph · 12-16
Closed season
Season reopens 1 October. Plenty of other water available now.
Closed — confidence not applicable today.
What moved it
  • Flow26.9 m³/sLast reading 6h ago
  • Water temp8.2°C
  • ClarityClear
Today's fly
Hare & Copper Nymph
Hare & Copper Nymph12-16
High-confidence seasonal pick
Conditions on the water
Live gauge
Flow
Steady
26.9 m³/s
Last reading 6h ago
Water temp8.2°C
ClarityClear
Weather4°C
WindN 12 km/h
Pressure1013 hPa
Rain · recent0.7 mm
Rain · ahead1.8 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

How these readings are sourced

Weather-only: no live gauge wired. Colours after rain — best falling and clearing.

Water temperature for Brown Trout
Cool — slow
8°C est.ideal 1016°C
0°14°28°
How to fish it · for Brown Trout
When
Nymphing can work through most of the day.
Where
Cover mixed depths.
Method
Start with tight-line nymphs and adjust if fish rise or drift higher.
Kit
9 ft #4 rod, floating line, 12 ft tapered leader to 4–5 lb fluoro tippet.
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 3 active hatches hour by hour with Pro.

Start free trial

14-day free trial. Cancel anytime.

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds with Pro.

Start free trial

14-day free trial. Cancel anytime.

Evidence
ModelledModerate confidence

Modelled from regional ecology — no survey or occurrence data for this water yet.

Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
2
2
2
1
1
2
2
Deleatidium / NZ Mayfly DunHatch
3
3
3
3
2
2
3
3
3
Burrowing Mayfly / Green MayflyHatch
3
2
2
Caddis / SedgeHatch
3
3
3
2
2
3
Cased Caddis / CreeperHatch
3
3
3
2
2
3
3

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

Ranked for today
Brown Trout fly box
Permits & access
Permit required — see local rules.
  • Otago Fish & Game — a Fish & Game licence is required
  • Check the current Anglers Notice
  • Check Clean Dry (didymo present)
  • Respect private-land access.
What's coming
Plan ahead
5-day outlook
Other water nearby · 1
About this water

The Pomahaka is one of West Otago's best-kept brown-trout rivers — a friendly Clutha tributary with long glides and runs and a reliable afternoon mayfly hatch, fished much like the Mataura. Time your day to the rise, sight-nymph the runs between hatches, and add summer terrestrials. Best low and clear.

Under the surface

The Pomahaka winds out of the Umbrella and Old Man ranges through the tussock and farmland of West Otago to join the Clutha, an unhurried river of gravel runs, willow glides and a famous afternoon mayfly rise. Brown-trout water of real quality, less pressured than its bigger neighbours.

Wading: Slick gravel, didymo, colour after rain

Hatches & food

Fish & Game name mayflies and caddis as the predominant invertebrates in the river's food community, but the source gives no defensible emergence window — useful for fly selection, not for timing a rise.

  • River
  • Mixed sedimentary
  • Unconfined
  • Pool riffle
  • Glide
The full read · show the working · for Brown Trout · confidence 75%
How the 0 is built — score × weight = contribution
Temperature68 × 28%19.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity39 × 12%4.7
Conditions total= 72
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
Warmer water — toward the 10–16 °C ideal band — would lift the temperature score.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
  • Trout 1 October30 April (upper) / year-round (lower)

    Otago Fish & Game licence required. Legal status: guidance_not_permission.

Related guides
Booking & contacts