Guest Blogger: Joe Dellaria, Woodbury MN

Let’s look at the three different days described earlier in the series to see how water visibility influenced where the fish were caught. Recall that these three days occurred over three consecutive weeks on the same section of my favorite river while using the same or very similar flies.

Day 1: High Water Visibility (i.e. you can see the bottom clearly in two or more feet of water)

  • Time-first week of March

  • Weather-clear and sunny

  • Water-low and exceptionally clear

The first outing of the year started at midday and the water was clear. I could see the bottom in about four feet of water. I caught 13 fish. Ten took the #16 bead-head nymph. Three fish were caught on the larger mini-streamer. Fish were basically in their typical holding areas. Since it was a sunny day and the water was very clear, the fish were holding against obstructions in two to three feet of water. Some of the fish came in shallower water in riffles where the surface disturbances caused by the current and the rocks in the riffle decreased water visibility. The takes showed as subtle pauses on the strike indicator.

The three larger fish all came late in the outing. The sun was lower in the sky. These fish were all holding near the head of a riffle. The takes were obvious. The float indicator jumped four or more inches as the fish aggressively took the larger fly. Because the light was lower the water visibility was medium, the fish moved into shallower feeding lanes. They were there for one reason, meat! They pounded the mini-streamer. It almost makes you laugh when the float indicator jumps that much.

As you can see, even during an outing, conditions might change. Early in the outing it was sunny and bright and the water was exceptionally clear. These are high water visibility conditions. The fish only took the smaller fly with a gentle sip in deeper water. Later, under lower light the fish moved shallower and were hammering the larger fly. Initially they could not hold in the shallower positions because of the light and high water clarity (i.e. high water visibility conditions). As the light dropped the shallower feeding lanes became acceptable as the water visibility dropped to medium.

Day 2: Low Water Visibility (i.e. you can see the bottom clearly in less than 1 foot of water)

  • Time-second week of March

  • Weather-cloudy with a gentle rain

  • Water-high and cloudy

The second outing was after a flash run-off. The water was close to a foot higher than usual and the bottom could be seen clearly in under a foot of water. In addition, it was overcast with a slight drizzle. These are low water visibility conditions. Most of the fish came on the larger mini-streamer in about one foot of water or less. The fish were concentrated near the sides of the river having less current.

Because the river was up nearly a foot, the current speed on the “slower” side of the river was still quite brisk. The takes were aggressive. Many of the fish had the entire mini-streamer in their mouths. The overcast skies and cloudiness of the water made it possible for these fish to move into shallower water to feed. The fish pounded the larger fly. This is typical of low water visibility conditions.

Years ago, I learned the value of low water visibility caused by cloudy water on a normally clear stream. It was mid-summer and I was working my way towards my favorite hole. The goal was to time my arrival at the hole just as the sun was going down and I had plenty of time. I was casually casting up and across the stream. Normally the stretch of river I was fishing was unproductive at that time of day. However, it had rained in the morning so the water was cloudy. You could clearly see the bottom in about a foot of water but you could easily discern boulders in the water in about two feet of water.

I picked out a boulder roughly in the middle of the river and cast several feet in front of it and started stripping the fly back in six- to eight-inch pulls. The fly was just in front of the boulder and about to go around it when one of the biggest trout I had ever seen on the river lunged at the fly. The fish caught me completely off guard and I jerked the fly right out of his mouth before he could close it.

Unbelievable! I had never seen a fish by that boulder before. This time conditions were perfect. The water was hazy and it was cloudy producing low water visibility. That was sufficient to induce this fish to move shallow and feed. From that day on I always cast that boulder no matter what. But I usually raise or hook a fish only under lower light conditions.


Day 3: Medium Water Visibility (i.e. you can see the bottom clearly in 1 foot to less than 2 feet of water)

  • Time-third week of March

  • Weather-cloudy with a gentle rain

  • Water-slightly high and just a little cloudy

The final outing described was after the water had cleared substantially. The bottom was visible in about two feet of water and it was overcast. The water level was almost normal. In this case, the slight haze in the water and the overcast skies produced medium water visibility where fish move into shallower feeding lanes. The fish were either sitting tight to an obstruction or at the head of a riffle. Almost all of the fish came in less than a foot of water and took the larger fly. They were very aggressive hits. While I caught fewer fish, the average size was well above my average for that river.

Each of these days had very different water visibilities and water levels. Good numbers of fish were caught on each outing. However, the fish were taken from very diverse types of cover. Under high water visibility conditions (water was clear and it was sunny), the fish were caught in deeper areas with either an obstruction or an edge to create their holding spot. Low water visibility conditions (high water, low water clarity, and overcast) the fish were scattered on the edges of the river and did not relate to obstructions. Finally, under medium water visibility conditions (normal water height, slightly hazy water, and overcast) led the fish to hold in shallower water next to obstructions. The combination of water level and water visibility clearly modified the where the fish fed and the aggressiveness of the fish.


    1. Hi Joe,
      I like your name! Let me know when you determine what you think. I would encourage you to read the last two segments as they will pull together some other observations.
      Tight Lines,
      Joe Dellaria

  1. Thank you for putting in the leg work by recording your findings with specifics and sharing those findings. I’ve had roughly the same results, but never recorded the specifics. This research helps make sense of what I have experienced and provides perspective on what will happen given the specifics on water clarity and levels.

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