So a very tiny dam that probably will fail at some point (which might not be bad).

But it might be enough to reclassify the project from a new construction to something else that doesn't require negotiating so many permits.

Beaver dams are like step dams. The bad ones people talk about are the huge dams which alter the environment drastically often creating artificial lakes.

Beaver dams on the other hand slow down water flow to some extent and alter the direction of water flow slightly. These smaller natural dams are so good for little species to thrive.

Human made dams are not always comparable with bever dams, to say the least. The wildlife have learned to coexist with beavers. Human dams on the other hand can be a lot larger, not allow for emigration, drain large areas and van themselves be drained.

So, lakes are bad? Nothing lives in, around, or on lakes, right?

I am responding simplistically, because truthfully, it is simple. Dams replace one healthy, vibrant ecosystem with another.