Tailwater · Mixed · Northern California, US

Lower Mokelumne River

Still water on the Mokelumne River near Lodi, California, with trees and a small boat reflected on the surface.

Short, cold tailwater below Camanche Dam, run by East Bay MUD rather than the Bureau, and it punches above its weight for wild rainbows holding over clean gravel.

Tomorrow · About as good as it gets
Czech Nymph
Forecast · Tomorrow
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.
75% projected
Today's fly
Czech Nymph
Czech Nymph
Conditions on the water · Tomorrow
Estimate
Level
Dry recently
No gauge reading
Water temp11.5°C
ClarityClear
Weather20°C
WindN 6 km/h
Pressure1015 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

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

Water temperature for Rainbow Trout
Ideal
12°C est.ideal 10–18°C
0°14°28°
How to fish it · for Rainbow 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
Good — water temperature is right today, though time of day could be better.
Likely species
Mayflies
Caddisflies
terrestrials
Hatch timeline · tomorrowPeak at 11am

12pm(now) — Western Blue-Winged Olive

Stage: On emergersApproach: Emerger or dryActivity: 82%
Also:Black Midge46%
Peak emergence window7 food groups active

Peak activity at 11am — Western Blue-Winged Olive (Western Blue-Winged Olive, Peak emergence window)

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.

Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 with Pro.

Start free trial

14-day free trial. Cancel anytime.

Evidence
Records-basedModerate confidence

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

Through the year
0–3 scale · September 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
Western Blue-Winged OliveHatch
2
3
3
3
3
3
3
3
2
Pale Morning DunHatch
2
3
3
2
TricoHatch
2
3
2
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2

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

Ranked for today
Rainbow Trout fly box
Permits & access
Permit required — see local rules.
  • Open all year; barbless, with low-flow / steelhead closures — check CDFW
  • ESA-listed steelhead present: handle with care
  • Flow tracks Camanche releases.
What's coming
Plan ahead
5-day outlook
Other water nearby · 2
Lower American River
49 km
Rainbow trout
Lower Stanislaus River
55 km
Rainbow trout
Gallery · 2
  1. Still water on the Mokelumne River near Lodi, California, with trees and a small boat reflected on the surface.
    Symmetry
  2. Terrain map of the venue
    Terrain map
About this water

Short, cold tailwater below Camanche Dam, run by East Bay MUD rather than the Bureau, and it punches above its weight for wild rainbows holding over clean gravel. It also carries ESA-listed Central Valley steelhead, so those fish get a wide berth and a gentle hand. It's a drift-boat and wade fishery best in the cooler months — blue-wings and midges in winter, caddis as it warms, and the familiar egg bite behind the autumn salmon. Flow is whatever Camanche sends down, so the weather upstream barely enters into it.

  • Mixed
Conservation note

Holds ESA-listed Central Valley steelhead. We surface their presence only — no catch score, no go-get-'em. Treat any you encounter as the rare thing they are.

Water quality · US Clean Water Act
  • Aquatic life: Impaired
  • Fish consumption: Impaired
What this classification means

Fish consumption: Consumption advisory (Metals Other Than Mercury) — fish for sport, not the table.

EPA ATTAINS assessment unit 'Mokelumne River, Lower (in Delta Waterways, eastern portion)' (CAR5440000019980818095133), 2024 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Oxygen Depletion, Metals Other Than Mercury, Mercury, Total Toxics. 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) · CAR5440000019980818095133

The full read · show the working · for Rainbow Trout · confidence 75%
How the 79 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time45 × 13%5.9
Pressure75 × 7%5.3
Insect activity59 × 12%7.1
Conditions total= 79
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
Apple MapsGoogle Maps
Seasons & zones
  • Trout 1 January → 31 December
Related guides
Euro Nymphingsubsurface methods
Casting instructors near here
Booking & contacts