How to Fly Fish During High Water or Runoff: Pro Tips

Spring and early summer bring a surge of energy to our rivers — snowmelt from the high country barrels downstream, swelling flows, and turning once-clear water into a swirling mix of sediment and foam. For many anglers, this annual runoff signals a break in fishing. But for those in the know, high water is not a barrier — it’s an opportunity.

As a professional fly fishing guide who's spent countless days on swollen rivers, I can tell you that some of the most productive days of the season can come during high water. It all comes down to adjusting your tactics, reading the river differently, and making fly selections that match these dynamic conditions.

Let’s break it down — technique, fly selection, water choice, and mindset — so you can confidently hit the river when others are packing it in.

Understanding High Water Behavior

First things first — high water changes everything for trout. Their prime holding lies are no longer in the middle of the river where current speeds are too fast to feed efficiently. Instead, fish seek refuge along the banks, behind structure, in side channels, and in eddies where they can conserve energy and ambush food as it funnels by.

The river is essentially reset — your usual go-to spots might now be unfishable or blown out, but new opportunities open up where fish are pushed into accessible, shallow water. The key is to look for soft seams, edge water, and slower side channels where trout feel safe and have access to food.

Where to Focus: Targeting Productive Water

During high flows, ignore the deep mid-river runs and fast chutes. Instead, work these areas:

1. Inside Bends and Banks: These offer slower water where fish can hold with less effort. The bank-side seam between fast and slow water is a prime feeding zone.
2. Back Eddies and Sloughs: These are calm pockets where food collects. Don’t overlook these — trout often stack up in these slower areas, especially if they’re near cover or depth.
3. Behind Structure: Big boulders, submerged logs, or any midstream obstruction can create a bubble of soft water behind it. These are classic ambush spots.
4. Side Channels: During high water, side channels become more active. Trout may move into these areas for both food and cover.
5. Flooded Banks or Willow Lines: Yes, even submerged grass and willow roots can hold fish. If it’s knee-deep, has decent visibility, and is moving slowly, fish it.

Remember: fish are looking for safety first, then food. Your job is to find those sanctuaries and put your flies in the zone.

Fly Selection: Think Big, Bright, and Bold

When runoff muddies the water and increases volume, you’ve got to dial up the contrast and visibility of your flies. This is not the time for dainty #20 midges. Go bold and buggy.

Here are some of my go-to patterns:

Nymphs:

• Pat’s Rubber Legs (Stonefly patterns) in black, brown, or coffee/black – size 6–10
• Tungsten Prince Nymphs or Copper Johns – red, chartreuse, or copper – size 12–16
• San Juan Worms / Squirmy Wormies / Wire Worms – pink, red, wine or Brown – size 6 –12
• Flashback Pheasant Tails or Hare’s Ears – size 12–16
• Egg patterns – especially in orange or peach during spawning periods

Streamers:

• Conehead Woolly Buggers in black, olive, or white – size 4–8
• Thin Mints
• Double Gonga, Rusty Trombone for meat chuckers.

Dry/Dropper Setups:

On the days after the water peaks and begins to clear, try a Chubby Chernobyl in purple or tan (size 8–12) with a nymph or worm dropper about 18–24 inches below.

Fly Color Tip:

In stained water, color matters. Think contrast and visibility:

• Black: Highly visible against stained backgrounds.
• Purple: An underutilized color that works in all conditions.
• Red/Pink: Deadly for worms and eggs.
• Olive & White: Great for streamers when fish are chasing.

Rigging and Techniques

1. Heavy Nymph Rigs:

Use a 2–3 fly nymph rig with ample weight (either split shot or weighted flies). A large indicator (like an Oros or Thingamabobber) helps with visibility and flotation. Fish deep and slow — don’t be afraid to add weight until you’re ticking bottom.

2. Tight-Line / Euro Nymphing:

When visibility is at least 12–18 inches and you're fishing close, euro nymphing can be deadly. The direct connection helps detect subtle takes in soft water near the bank.

3. Streamers:

Use a sink-tip line or weighted flies, and fish them slowly. High water fish aren’t looking to sprint — they want an easy meal. Focus on casting upstream and retrieving slowly down seams and along structure.

4. Dry-Dropper Along Edges:

When flows drop slightly and the clarity improves, work edge water with a large foam dry and a dropper nymph or worm. Fish may suspend higher than you think in these soft zones.

Gear Adjustments

• Leader/Tippet: Go heavier. 3X or 4X is often fine — fish aren’t line-shy when the water's dirty.
• Wading: Safety first. High water is no joke. Avoid deep crossings, use a wading staff, and always have a belt on your waders.
• Wading Position: Fish from the bank when possible. Many high water trout are within a rod’s length of the shore.

Mindset: Embrace the Change

Fishing high water isn't about replicating your favorite summer techniques — it's about adapting and using what the river gives you. Sure, it may look intimidating at first glance, but once you learn to read the new structure and use bold patterns to your advantage, you’ll find fish willing to eat and relatively untouched by pressure.

Some of my most rewarding guide days have come during runoff, putting clients on trout in places they never thought to fish — literally at their feet, inches from the bank, in water that looks like chocolate milk.

Final Thoughts

Runoff season doesn’t mean fishing is over. It just means fishing is different. With the right flies, smart tactics, and a little creativity, you can turn a swollen river into a playground of opportunity.

So next time you see that USGS gauge spike, don’t cancel your trip — gear up, adjust your game plan, and go make it happen.

See you on the water.

Tight lines!