We probably need the wall on our side, but that means we need a way for animals, and our own people, to get through to the other side to access the river.
There are places where the river’s changes have actually left american soil on the far side of the river now, and those people sometimes use boats for access to their own country — so we need to account for that if we build a wall.
What we need is a barrier that prevents unwanted people from easily accessing our country. You build a solid wall, people can still just go around the ends in either the pacific ocean or the gulf.
And given that California is a sanctuary state, and they have the beaches easily accessed by Mexicans through the Pacific ocean, we’ll clearly need better coast guard enforcement to keep boats from reaching that shore.
We should put up cameras all along the border, and let americans monitor them,.
Irrigation pipes, problem solved.