Dupage River 6/18

[ronk]

Fished a cupl hours in 3 areas.Caught a 14"er in the first few casts on a bluegill fly. Figured that was a good omen but that was the only fish I hit.Just as this year's hi murky water kept the algae at bay earlier this Spring it has also kept the weeds from being as bad as they've been in recent years by this time.They are on the increase however and as Summer wears on likely will become as bad as ever.The water is still hi and murky but falling and clearing at least until the next rain due in a cupl days.

The main reason for this post is the appalling increase in the amount of silt in the river.When it first started becoming noticeable a few years ago it was largely confined to slackwater areas.It now exists throut the entire main branch even along shorelines having a good currentJust about everywhere you step off shore you step into silty mud of varying depth and if you're foolish enuf to step off in a slackwater area you risk the fate of one of those prehistoric beasts in Labrea.What I don't understand is where all the silt is coming from.I've waded just about the entire main branch from the confluence of the east/west branches and have never seen any evidence of anything that could account for such a massive accumulation of silt.Just about everywhere I've seen there's been vegetation buffering the shorelines etc. Does anyone have any ideas of the source(s) of all this silt? Could it be washing down from either or both of the branches?

[Jim Kast]

Sounds like my few hours on the Dup today. 1- 4" rockbass!

[Norm M]

The water table is saturated and with all the rain the runoff is moving into the water quicker carrying more silt with it instead of soaking into the ground. The higher flows are dumping the load anywhere the current slacks even a bit . The leads to wider distribution of the silt load in non traditional areas.

 

Guess what will prolly take root in the silt .

[ronk]

The water table is saturated and with all the rain the runoff is moving into the water quicker carrying more silt with it instead of soaking into the ground. The higher flows are dumping the load anywhere the current slacks even a bit . The leads to wider distribution of the silt load in non traditional areas.

 

Guess what will prolly take root in the silt .

 

Norm,

Thanks for your response.While you have a good point the silt has been increasing for the past 5 years or more during years of average to below average precipitation.

[Norm M]

Urbanization is prolly the biggest culprit. Tear everything up, lots of loose soil . Add more blacktop and concrete which doesn't allow the water back into the ground but increases the amount and the speed in which the precipitation moves into the rivers.

 

Instead of buffer zones of tall grasses to slow things down you have lawns allowing quicker access to the water. Less long grasses and fewer trees also mean more banks liable to erosion.

 

Add in farmers cropping to the edge to grow more grain to take advantage of the rising prices. Less money for the CREP program and it prolly pays better to grow grain to to put aside into CREP .

 

More potential sources of silt , more silt in the flow even with lower levels of precipitation.

[ronk]

Your right ,Norm.Those thin strips of vegetation along the banks must not be enuf anymore.

 

 

[Steve S.]

Throw in the various construction projects along or over the river. Erosion control measures are normally in place, but when high water comes they become ineffective. That can generate a lot of silt. There is a bridge reconstruction ongoing at the moment near my house, and another one planned for a major road. I'm sure there will be some impact on this stretch of river once the projects are complete.

[Tim Smith]

Erosion control measures are normally in place, but when high water comes they become ineffective. That can generate a lot of silt.

 

I think Steve may have something here. Most sediment moves in major floods.

 

Ron, I'd be very curious to know how the algae sets up this year in the Dupage and Kankakee as the water goes down. Later in the summer we got lower rates of algae accumulation in our statewide surveys.

 

Maybe that was due to the faster growth rates and more grazing by animals eating algae or something else.

 

Maybe it will help keep things less clogged. Maybe not.

[ronk]

I think Steve may have something here. Most sediment moves in major floods.

 

Ron, I'd be very curious to know how the algae sets up this year in the Dupage and Kankakee as the water goes down. Later in the summer we got lower rates of algae accumulation in our statewide surveys.

 

Maybe that was due to the faster growth rates and more grazing by animals eating algae or something else.

 

Maybe it will help keep things less clogged. Maybe not.

Tim,

The algae in the Dupage is a coldwater type.It appears in Spring when the water's cold provided it's clear too and begins to disappear in late Spring/early Summer only to be replaced by 2 varieties of long skiinny weeds.The algae retuns again in Fall as the water cools but isn't as bad as it is in Spring.At least that's the way it was last year.This year the algae was well contained by all the rain keeping the river higher and murkier than last year when the algae was really thick enuf to actually make wading difficult.Never saw it that bad before. Between the weeds the algae and the silt it's become one sick river.The Fox is now the least screwed up river of the 3 in our region. Who'd a thunk it?