The Columbia River tribes are probably the only groups that can afford to build nature scape hatcheries. It is much more complicated than just finding an underutilized stream, as you have indicated. The Nez Perce tribe has built a nature scape chinook hatchery. Anyone interested can check the link below for the details. The second link relates to initial results of the program. Nature scape hatcheries make nice parks, if nothing else. The Weaver Creek spawning channel in BC is a fish tourist destination to view spawning salmon.

Nez Perce Hatchery

Hatchery Chinook