Gone are the pyramids’ shiny outer surfaces. The Colossus of Rhodes fell by the sea. Roman armies razed the Temple of Jerusalem, one of the greatest architectural marvels ever.

Dams last less long than most big projects, though longer than Herod’s completed temple. The American Society of Civil Engineers figures that the average life of a dam spans 50 years. The older, the less safe, and the more cracks and holes need filling.

There are a lot of dams in America. And their age is becoming a problem. James Workman, writing for the Property and Environment Research Center in a PERC Report, writes that there are “79,000 high-hazard dams the size of a two-story building or higher” in our country, and “two million smaller dams.” Workman claims that the “number of obsolete, orphaned, or ‘deadbeat’ dams has risen; today 15 percent of America’s National Inventory of Dams are classified as being of ‘indeterminate ownership.’”

It is time to unbuild many of those dams.

How? Workman has come up a nifty exit strategy for businesses, governments and communities that own (or are merely left with) deadbeat dams. “Junk bond” their removal. The dam sites and reservoirs have more value take apart than kept together. So finance the removal on those grounds alone. Leverage environmental set-asides and similar laws and business factors, and get these dams unbuilt safely, for all our gain.

Junk bonds for dams! What a concept.

This is Common Sense. I’m Paul Jacob.