Proposed Solution for Hydroelectric Dams

The other day, I watched 60 Minutes, the TV commentary that dares to tell the truth. They reported on hundreds of millions having been spent to ‘save’ salmon, which have all but disappeared, due to a number of hydroelectric dams having been built along rivers discharging into the Pacific.

Apparently, salmon get trapped in the turbines, on their way to spawning pools up the rivers, and, more than likely, on their way back to the ocean. The authorities went to great length to save the dams. Their feeble attempts to save the salmon are among the most inane I’d ever heard of in my life. It is frightening that the USA authorities can employ that many people whose stupidity borders on wilful negligence.

Surely, an addition of 2 to 3 feet to the dam’s height, to compensate for 2 or 3 new openings in (or around) the dam, would solve the problem permanently, for a tiny fraction of the cost.

The new stepped openings, resembling cataracts, would allow free flow of water for the salmon, while access to the turbines would be protected with wire mesh on both sides of the dam. After a short period of adjustment, the present water level would be maintained, the salmon would have unrestricted access to spawning grounds, and millions and millions of dollars would be saved. Is there something wrong with my reasoning?

PS. Perhaps I should mention that, though now retired, for some 40 years I'd been gainfully employed as an architect in England and in Canada. (RIBA,MRAIC,OAQ)