In a restored wetland, sediments and turbidity are lower below beaver dams than above. Why is this?

Question

In a restored wetland, sediments and turbidity are lower below beaver dams than above. Why is this?

Answer 1

Below the dam is still water sediment in still water falls to the riverbed. Above the dam the water is flowing and the sediment is being continuously mixed in the water.  Turbidity is the clearness of the water so above the water is more turbid from all the sediment in the water and thus is less turbid below from the lack of sediment. As a side note- sediment is the number one pollutant of water.

Answer 2

the dam slows the water down (reduces turbidity) and it filters the water (less sediment)

Answer 3

The slower the water moves the more material falls out of the water.

Answer 4

Here's an experiment for you:  pour a bunch of sand or dirt into a glass of water and stir vigorously for a couple minutes.  How does the water look while you're stirring?  Now leave the water alone for about 10 minutes.  How does it look now?  Now carefully pour the water into another glass and do the same thing (stir for a couple minutes and then let it sit for about 10 minutes).  were your results any different?  The first glass represents the moving water of the stream or river when it's being stirred, and the calm beaver pond after it sits.  The second glass represents the moving water below the beaver dam when it's being stirred and any calm areas in the water flow after it sits.  Does this suggest anything to you?