This looks like directions to open a "water valve"
which is what led to the TMI problem and others, if memory serves.
It looks like Homer's head...
Someone should check when the original image was posted last year and see if it was about the time some vague threats were discussed regarding the Hoover Dam.
I did a brief search on yahoo and pulled up something at ATS from last summer (sept) but didn't find anything at FR, but seem to remember the same discussion. (lat long)
You don't need a plane for a bridge. You can fly "up" to a dam. Lake Mead is the Las Vegas water supply. But you would need some serious explosive to breach that. . .
"the water the water the water"