Remember that the beaver's dam is not efficient from a human standpoint. The sucker leaks along it's entire length and when a slug of water from a thunderstorm hits, the dam is overtopped along it's whole length. To maintain it's integrity the whole beaver family works on it 24/7, though mostly at night. Also, the beavers are constantly thickening and elevating it. So over time, the dam will flood a larger and deeper area. In a flat floodplain such as I am describing the beavers often build networks of dams cascading into each other with enclosed pools at slightly different elevations. So it is, no question, a multivariate problem.

I think your solution isn't too far off, though completely unrealistic. I'd rather sit in a tree at night with a .22 than dig that many trenches with a shovel and pick-axe.

I assume that the number of pipes decreases with the pipe diameter as some sort of power function. What if I went to a 10" or 12" pipe? How about if we assumed that the dam is only 75% efficient? 50% efficient?

How much do I have to pay you for this? I might have to change my screen name.

B