While not exactly similar to North America continental divide, traversing from the Yangtze river to the North would require traversing some hilly or mountainous area. [0] mentions that there is some uphill location that required pumps.

At this point, there is no feasibility studies on the NA East-West water canal. There is no idea on how efficient it is vs desalination (in terms of energy), its ecological impact, and the required cost for the design and construction.

My main idea is that we should not dismiss the idea and that the Army Engineering Corps should at least do feasibility studies on it*. A proper feasibility studies could unveil the true challenge, benefits, and disadvantage (rather than anecdotal guess) of the water canal.

I am not exactly familiar with the NA Southwest and Southeast but the canal could possibility bring other benefits, such as reducing the heat in the region and opening up new land for farming and irrigation. It could have a trigger a new economic growth while at the same time, reducing flood risk at the Southeast. There is also a possibility that the this could trigger a transfer of wealth (in terms of payment for water, technical skills etc) from the relatively prosperous south West Coast to the Southeast, reducing inequality. Of course, I am not eliminating the possibility that the canal could be a white elephant and trigger untold ecological and natural disaster, but unless a feasibility studies is conducted, we never know.

*US Government, or at least the Federal Entity, are already doing multiple kind of planning and research for dizzying array of contingency. Why should the same mindset is not applied for possible infrastructure development?