On 1 Sep 2006 18:31:58 -0700, "
wrote:

Impressive. Where is this? It looks as if it has been used a lot and
I wonder about the economics of this vs a lock system.

I was wondering about the lock alternative also. I'm guessing that
either the terain precluded a lock for some reason ot that the height
of the dam would have necessitated a cascade of locks which might have
had the effect of limiting boat length. The only other possibility
that I can think of is that making the river navigable was an after
thought.