Despite a last minute call for volunteers, high heat and humidity, a late delivery and a rock pile that was not nearly as close to the creek as I had hoped — 5 tons of rock have been added to the deflector immediately upstream of the bridge pool. Fred Dewees, brand new club member Steve Buck, and I waited an hour for the delivery before we started carrying and tossing stones.  A little later, Ed Collier got the word and pitched in with fresh muscles just at the right time.  Everyone worked hard, but we were able to finish the job in less than 2 hours of working time.

When the work was proposed, I was told we would need 5-6 tons of stone.  I erred on the safe side and got 5.  Although I am glad we didn't have any more to move with just the four of us, I think we are going to need another 5-10 tons of stone before we will be finished with this deflector.  The angle between the bank on the downstream side and the point of the deflector in the stream should be 60 degrees or less.  I am going to measure it out, but I don't think we are there yet.

Several people have asked what the deflector is supposed to do.  To get a precise answer, I consulted the book Better trout habitat: a guide to stream restoration and management by Christopher J. Hunter, Tom Palmer, Ellen Meloy, Montana Land Reliance (Trust):

The partial barrier to water flow deflects current towards the opposite bank.  By partially blocking flow, the deflector causes water to back up or pile up to some degree, which results in increased water depth and velocity. The water scours a pool just downstream and opposite the deflector. A portion of the stream's sediment is deposited in the lee of the structure.  Thus, a bar forms downstream, and on the same bank as the structure.

In this case, I think it should also reduce errosion of the bank downstream and adacent to the deflector.  Below is a picture of the work site after the rain we had from Hurricane Bill.  As you can see, more stone is needed to bring the new newly added area up to the appropriate level.

	1. Written by Zach Pryor on 02-02-2010 09:23 - Guest
	Hi Greg,    I've been involved in the construction of many channelizers throughout the freestone streams in central PA. Generally, when loose stone is added, no matter what the size, it tends to "disappear" rather quickly and it's effectiveness is lost after only a few periods of high water. I usually build a "framework" of logs (landscaping timbers or telephone poles work well) to keep the rock fill where it belongs. The timbers are drilled and staked with rebar (4' deep or so). Once your timbers are down, the interior of the channelizer is filled with stone. Fencing (chain link works well) is sometimes used to cover the rock fill and keeps the entire system in place, no matter how high or fast the stream may get. These channelizers can last for many years with little or no upkeep...just a note:)

	2. Written by Greg on 09-02-2009 20:14 - Guest
	I know the type of cribbing you are referring to - we have built more than a few devices anchored as you describe. All of our in-stream projects are designed by a PFBC Habitat Manager and permitted by the PA DEP. I don't know why, but this plan did not call for any cribbing.

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