Tailwater · Mixed Metamorphic · Maryland, US

Gunpowder Falls

A rocky pool on the Gunpowder Falls river surrounded by autumn foliage, with a large boulder in the foreground.
Today · About as good as it gets
Pheasant Tail Nymph (18-20)
Forecast · Today
About as good as it gets
On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
90% projected
Today's fly
Pheasant Tail Nymph (18-20)
Pheasant Tail Nymph (18-20)
Conditions on the water · Today
Live gauge
Level
Falling
0.33 m
Dropping after lift
Water temp11.2°C
ClarityClearing
Weather11°C
WindN 26 km/h
Pressure1020 hPa
Rain · recent3.1 mm
Rain · ahead0.0 mm

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

Water temperature for Brown Trout
Ideal
11°C est.ideal 10–16°C
0°14°28°

A dam sets this river's temperature, not the weather, so it can shift several degrees within hours when the release changes. It also warms as it runs away from the dam.

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.
Why this works
Excellent — water temperature is right today, though insect activity could be better.
Likely species
Mayflies
Chironomids
Damselflies & dragonflies
Gammarids
Hatch timeline · todayPeak at 12 Uhr

12 Uhr(now) — Eastern Blue-Winged Olive

Stage: On emergersApproach: Emerger or dryActivity: 63%
Also:Black Midge38%
Peak emergence window5 food groups active

Peak activity at 12 Uhr — Eastern Blue-Winged Olive (Eastern Blue-Winged Olive, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

Supporters see the full sub-surface read.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 4 as a supporter.

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Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
2
2
2
2
1
SulphurHatch
2
3
2
Trico (Eastern)Hatch
2
3
3
2
Eastern Blue-Winged OliveHatch
2
3
3
3
3
3
3
3
2
Eastern Summer BWO (Drunella)Hatch
2
3
3
2

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

Ranked for today
Fly box · Brown Trout
Permits & access
Permit required — see local rules.
  • Maryland licence required; catch-and-release wild trout regulations on the tailwater reach — verify current MDNR rules and the fly-fishing-only sections.
What's coming
Plan ahead
5-day outlook
Gallery · 2
  1. A rocky pool on the Gunpowder Falls river surrounded by autumn foliage, with a large boulder in the foreground.
    Autumn Along the Gunpowder
  2. Terrain map of the venue
    Terrain map
Water quality · US Clean Water Act
  • Aquatic life: Not assessed
What this classification means

EPA ATTAINS assessment unit 'Gunpowder Falls' (MD-02130805-Gunpowder_Falls), 2024 Integrated Report. Aquatic Life use: not assessed. This is a Clean Water Act assessment-unit classification (the US analogue of WFD), not a live reading.

Status is for the Clean Water Act assessment unit covering this reach.

EPA ATTAINS (Clean Water Act) · MD-02130805-Gunpowder_Falls

The full read · show the working · for Brown Trout · confidence 90%
How the 85 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity51 × 12%6.1
Conditions total= 85
Can you trust it?
Water temperaturelive gauge readinggauge
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 1 January → 31 December
Related guides
Euro Nymphingsubsurface methods
Booking & contacts