As with almost every geographic “biggest” or “longest”, there are seven different ways to tabulate the results. The longest border between two countries would seem to be that between the U.S. and Canada. In total, it’s about 5,526 miles.
A hundred years ago those familiar drought conditions were plaguing San Diego. In 1915, San Diego was a small but growing city and its water needs were also growing. The rainfall records of that year don’t indicate severe drought conditions, and in fact by year’s end there was even more rain than average. But the city fathers were concerned about future needs and were looking for ways to increase the amount of stored water.
The project was informally called The Third Straw. All it took was drilling a 24-foot diameter tunnel through three miles of rock underneath the bottom of Lake Mead. Piece of cake. It did, however, take three years to eat it. The hydraulics of this scheme are, of course, complex, but they went more or less as follows.