Next the students position the log across the current forming a small dam. 

Rocks are added to secure the log in place.

Rejuvenating a silted-in trout stream is hard work!  Yet every year the students repair another section of the stream.

Here, with help and supervision from employees of the Pennsylvania Bureau of Forestry, the students carry a log to the stream.

The finished product.  The steam will naturally form a plunge pool under the waterfall providing a "hole" for trout to live and feed.  The waterfall also helps to oxygenate the water. 

Note:  The foam on the upstream (right hand side of picture) is naturally occurring by-product of the tannin in the water.