The wall shown in the picture is from an ongoing project, however Mulvaney specifically stated the new money would allow them to purchase more of this type of wall to continue the project.
He also explained this wall is levee wall that is needed along waterways. The reason for the slats is to allow water to flow through when there is a flood. It’s what the Border Patrol wanted installed, because it is the most effective.
Additionally, enforcing immigration policy is our responsibility. If we determine we want a wall, we should pay for it. If President Trump can get Mexico to fund it, then bonus. I wouldn’t expect my neighbor to pay for my fence, well unless he offered.
The reason for the slats is to allow water to flow through when there is a flood.
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That is also the prefence of the Border Patrol so they can see thru to what is on the other side.
Mulvaney alluded to that a couple of times in his presentation.