Water Clarity

[DaddyO]

Do you guys have any ideas of what is causing the cloudy / coffee water color on this river?

The last time that I saw this happen was when the Arkansas was higher than the Illinois causing it to wash up into this river. I don't think that is the case this time.

Another time that I saw this happen was when the Corps was installing and testing a new turbine at the Dam.

Aside from the obvious answers of Dirt and sediment, does anyone have any info on what is causing the coloration?

[ness]

Poop?

sorry

[asap52]

I think that the lake is still stirred up from the flood. I know the water that is coming in now is clear but there was so much dirty run off that came into that lake that it just hasn't settled yet. With the dry weather we are experiencing I would think it should start getting a lot clearer towards the middle of July.

Corky

[dgames]

We may not have trout left by the middle of July. Water temps have been getting up to 75 degrees at the gore gauging station when they aren't generating.

[JCWolfe]

Poor fish downstream, I checked yesterday at one point and had a reading of 68 where I was at, upstream from the gauge.

[dgames]

Regarding Daddy'os original question, I believe that is just the remnants of the massive influx of muddy water from the Easter weekend deluge and subsequent smaller flood in mid may.

The lake saw over 100,000 cfs inflow for a day or two with the Easter storm and the lake went from an empty flood pool to full in a matter of days. I think the volume of incoming muddy water just overwhelmed what was in the lake at the time.

[DaddyO]

I haven't been up to the lake. Is it muddy also?

[Bill Butts]

Hey DaddyO and all,

Good and obvious curiosity about the water clarity, since it is normally quite clear.

It was 3 years ago, if I recall correctly, that a similar scenario occured on your tailwater.

Extended weeks of very high inflow from the Upper IL deposited massive amounts of sediment into the lower lake.

Once the sediment settled into the depths of the lower lake, it(the lake) appeared normally clear, but the sediments made a continuing dirty clarity impact in the river below as releases gradually drew the accumulated sediment from the bottom of the lake.

I very clearly recall driving across the dam and seeing beautifully clear lake water, but then being quite disappointed to find the river water very brown murky. This condition did last for some weeks, but I don't recall for how long. So, even after the lake looks clear, it will take quite a while for the river to carry the accumulated sediment out of the lake.

The other issue that is created by this unusually massive high water event is that of water temperature in the tailwater below the dam. As a result of the Corps of Engineers (COE) having to blow incredible volumes of water thru the combination of turbines and flood gatess, lake water is being drained from both the top (flood gates) and nearer the bottom (turbines)of the lake. So, what does that mean?

The water drained off the top of the lake is generally the new inflow and somewhat warm in temperature, whereas the water drained thru the turbines is the usual important cool (trout friendly) water from greater depth, until that cool deep water is diminished or depleted and only warmer water remains. Odd but true.

Going back a few years again, many fishermen will recall that the water temps were so warm 24/7, that the ODWC postponed trout stocking for literally months until sometime in November after water temps consistently stayed cool enough to support trout.

In normal years, the challenge for keeping trout alive in the tailwater is keeping enough water volume flowing to keep the water temp cool enough for them.

I've watched daily flow levels and water temps on the web for days and weeks consecutively, and the clear pattern is very low flow during the a.m. to early to mid p.m., then after the water temp rises 8-12 degrees the COE releases enough water to bring the temp down to a survivable level for the trout. It is a daily cycle. So much of the upper few miles of the tailwater is very shallow, and warms very quickly with intense summer sun on the slow shallow water.

Hopefully, this is fairly clear to anyone who is interested. This year is a very unusual year with the extended high water, but it is not the only type of critical water event that happens in a tailwater trout stream. Fortunately, this unusually high water year is very rare but interesting it is now twice in the past 3 years.

Conditions will get better, but only time will tell how soon.

Great fishing to everyone!

Bill