[rich_sasha]

US engineering and attention to detail are, I agree, vastly different to the Soviet ones.

But concern for quality of environment for others vs corporate profit? Hmm not sure. The initial overuse of water resources in the West, endless stories of top soil and water table irreversible pollution with one chemical or other, or the reports that gas and oil companies had a full perspective in global warming in 1990s...

I'd agree, there possibly is an amount of water you could safely divert, and it is this kind of study that would determine it, but I'm not sure if the end result would reflect a sustainable solution.

[dsr3]

That's a very good point! The feasibility studies could solve the engineering question but social/economic (not as in cost-benefit, but in which group/organization/corporation will have more priority) is much more harder to solve.

But in my personal guess, a strong NGO/political activism by CA could influence the canal for the better. After all, construction of such canal, aside from having the support of the Federal Government, would requires an interstate compact/agreement. California would probably impose a decent environmental standard. Furthermore, Southeast states would also impose a strong limitation on the waters they will agree to divert. Unlike China, US States has strong sovereignty on matter like this and it would probably lead to some kind of equilibrium on the 'sustainable' water diversion rate.