If the pretender ever actually tries to build anything on the border, then the real fun starts

[lindysalsagal]

https://www.businessinsider.com/can-donald-trumps-build-wall-mexico-2016-3

First, a 1970 boundary treaty governs structures along the Rio Grande and Colorado River at the Mexican border. It requires that structures cannot disrupt the flow of the rivers, which flow across Texas and 24 miles in Arizona and define the US-Mexico border, according to The International Boundary and Water Commission, a joint US-Mexico agency that administers the treaty.

In areas where the border is defined on dry land across New Mexico, most of Arizona and California, structures have to be built so the wall doesn't obstruct natural run-off routes or otherwise induce flooding. Building in those areas can be complicated and costly. In sensitive sand dunes in Southern California, for instance, a "floating fence" had to be built to allow the natural movements of the dunes.

Then, there are the conservation issues. Groups such as Defenders of Wildlife and the Sierra Club sued over parts of the existing partial fence. And, federal regulations could prevent or at least significantly delay or increase costs of construction in certain areas.

Numerous fact-checking organizations have taken issue with Trump's estimate that the wall would be built for $10 billion to $12 billion. And they have rejected his contention that the wall could be funded by reducing the US trade deficit with Mexico. Figures released by the Army Corps of Engineers and the Congressional Research Service indicate that the total cost of the 650-mile fence has been $7 billion. And that doesn't include maintenance and upkeep.