Elon Musk has a boring company.
Use a combination of covered canals ( to reduce evaporation loss) and tunnels. If the average construction rate can be targeted at 10 miles per week per construction set, with 4 construction sets working, then even with only 60% efficiency that’s 100 miles per month or 2-3 yrs to complete. OF course the whacko’s will try to tie it up in court for 30 yrs. Declare it a national emergency and fast track everything and Trump can have it done in his next term.
And it is a national emergency because...?