Tailwater · Mixed · Massachusetts

Swift River

Swift River venue image

The Swift below Winsor Dam is the most technical trout water in Massachusetts and one of the most famous small tailwaters in the East — a cold, gin-clear river bleeding the bottom out of the Quabbin Reservoir, fishable every day of the year and crowded for good reason.

Prime · Brook Trout
Sulphur Comparadun · 16-18
Primelive now
About as good as it gets
River steady at a fishable height. On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
90% confidence
What moved it
  • Level0.66 mLast reading 21h ago
  • Water temp10.3°C
  • ClarityClear
Today's fly
SC
Sulphur Comparadun16-18
High-confidence seasonal pick
Conditions on the water
Live gauge
Level
Steady
0.66 m
Last reading 21h ago
Water temp10.3°C
ClarityClear
Weather19°C
WindSW 6 km/h
Pressure1016 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

Live readings — water temperature is an estimate where the gauge does not record it.

Water temperature for Brook Trout
Ideal
10°C est.ideal 1016°C
0°14°28°
How to fish it · for Brook 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 time of day could be better.
Hatch timeline · todayQuiet day

Hatch predictions

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

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 2 with Pro.

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Evidence
ModelledModerate confidence

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

Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
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
Brook Trout fly box
Permits & access
Permit required — see local rules.
  • MA has no closed trout season; Winsor Dam to Route 9 is fly-fishing-only with year-round catch-and-release in the immediate reach below the dam — verify boundaries against MassWildlife
  • A small, heavily pressured, low-clear technical water — finesse and care matter
  • Brook trout are heat-sensitive; the Swift stays cold, but handle wild char gently.
What's coming
Plan ahead
5-day outlook
Other water nearby · 1
Gallery · 1
  1. Terrain map of the venue
    Terrain map
About this water

The Swift below Winsor Dam is the most technical trout water in Massachusetts and one of the most famous small tailwaters in the East — a cold, gin-clear river bleeding the bottom out of the Quabbin Reservoir, fishable every day of the year and crowded for good reason. The top mile or so below the dam is fly-fishing-only and catch-and-release year-round, holding wild and holdover brook trout, browns and rainbows, plus the odd landlocked salmon that drops down out of the reservoir. It is finesse fishing in the extreme: low, clear, even flows; educated fish in skinny water; midges and tiny olives matched on long fine tippet. Cold all summer when freestones nearby are too warm to fish ethically, it asks for stealth, patience and small flies. A delicate, rule-sensitive, pressured classic — about as technical as New England trout fishing gets.

  • Mixed
Water quality · US Clean Water Act
  • Aquatic lifeImpaired
What this classification means

EPA ATTAINS assessment unit 'Swift River' (MA36-09), 2022 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Nuisance Exotic Species. 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) · MA36-09

The full read · show the working · for Brook Trout · confidence 90%
How the 83 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure75 × 7%5.3
Insect activity64 × 12%7.7
Conditions total= 83
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
  • TroutYear-roundYear-round
Related guides
Booking & contacts