Do good fences make good neighbors?

 Took a short walk up Boyle Ravine this morning and came across this "fence."  It was apparent that is purpose was to prevent fallen branches and other debris from clogging the culvert under the dirt service road.  That makes sense from a water management standpoint.  If the culvert got clogged, water would build up upstream from the road.  Eventually it would overflow and break through the road and flood residences downstream.  But building the road in the first place invited the problem. There are many complicated issues with managing Boyle Ravine which was threatened by the huge fires at the end of last summer.  However, for me, on this casual walk, it stimulated memories of Frost's poem, Mending Wall, in which the narrator questions his neighbor about why do we have this wall between us anyway.  Every winter "something" tries to tear it down.  he question is posed several times and the neighbor responds the same every time: "Good fences make good neighbors." That neighbor probably never visited the USA/Mexico border.

One stirred memory usually leads to another.  I grew up among New England's stone walls, so I remember why they were built, and used to enjoy running across the tops of them until one day I tripped and smashed my forehead on my way off the wall.  But walls mean something different to me now.  As fourth-grade engineers, we used to enjoy building little dams across streams and raising the water level a few inches to maybe a foot. One day we found a spot on a stream with high banks and thought we'd try to build a taller dam, just to see if we could.  When the water depth reached at least three feet, after a long afternoon of rock work, the dam burst and flooded a neighbor's corn field.  We were very frightened of getting caught and ran quite a ways before we were pretty sure no one was chasing us.  An experience with power over nature.  For some people, there's never enough power and hubris.  Thus, we have the Oroville Dam fiasco.  Now I mostly see dams, fences, and walls as dividers between peoples. I also remember in high school days crossing from Vermont into Canada dozens of times with no more inspections than a quick look at my driver's license.  Gone are the days.
Not too long ago, I crossed easily into Tecate, Mexico, and even Tijuana.  I wouldn't even try it today.