Perhaps we are over complicating this. A thirty six inch piece of very stiff music wire with a float at one end and a center pivot. The high and low point of the float should duplicated on the far end of the music wire.


The weight or load of the wire will be offset or neutralized by using a center pivot. Certain foams float with almost no detectable ingress into water. The only thing I can think of that is negative is the possibility of turbulence. Otherwise it should easily give you the peak levels.


This should allow at least a reasonable insertion into the end of a closed channel. You would want to be back in the channel at least a foot I suspect. Calibration is fairly easily accomplished. With a piece of paper or whatever secured close to the free end. You can easily pre calibrate it probably. Once it is set up. Since there is no loading on the foam from the wire. You can find the level of immersion of the foam from it's own mass. It should be small. Almost nothing for common sense purposes.

Foam even appears to have difficulty breaching the surface tension of water. If it's mass is distributed well. Drop a piece of foam on water in a wind and watch it go. There is an issue with this problem. As the water gets closer to the end of the channel it accelerates. That is why the level drops. It will be progressive from some point back in the channel. You post your results from the measured distance back up the channel. There are a few kinks in this approach though. If a lot of wind is exiting the channel at the same time.

Another thought was a series of tubes at different lengths. Grouped together with a compact but heavy base. Even vertical straws slid in along the bottom of the channel again with perhaps a stiff piece of music wire. The last straw in the arrangement with water in it is you max flow height. You want to design it so it presents the least frontal cross section to the flow possible. Personally I think the second choice of the two may be both easier and perhaps helps with the wind in the channel.

This problem could perhaps be solved with only one piece of information. It just is not there or I am missing it. Unless there is a water meter on the input. Whoever gave out this problem may have the answer. My guess is they are more interested in how an attempt is made to solve it. Or the methology if you wish.