It is worth mentioning up front that the wall hasn't even been started, but rather just worn sections are being upgraded and replaced.
Leaving aside the money involved, what is happening here in Tucson (or at least the local area, like Douglas) is that the local supply of water - never really adequate to begin with - is being consumed for concrete. And that is just for the footers.
So you can also expect the cost of beef to go up, as it is becoming impossible to keep cattle watered in a good chunk of the state.
This article is from September, prior to the full effects being realized. Leaving aside the worries about archaeology and local interest, the quantity of water being taken is huge by our standards, and will also damage the aquifer itself.
https://tucson.com/news/local/ancien...898f45619.html