Go northeast on 38 from Harlan KY for just under a mile and you’ll see these tunnels.
We didn’t know what to make of them, so, when I got back, I did a little research. They’re an Army job. Finished in 1992, these four tunnels divert the Clover Fork of the Cumberland River away from downtown Harlan, where there had been a history of flooding, into Martin’s Fork. The tunnels here are at 36.85526, -83.31546. The one the left carries the most water, normally. The actual input portals are at 36.85125, -83.31086, about 2,000′ away to the northeast going under Ivy Hill. The four tunnels minimize the possibility that one will get clogged up with debris in a flooding situation. Those who canoe or kayak say that these tunnels are safe, with smooth bottoms and moderate flow. The rock around the tunnels has been sprayed with concrete to stabilize it. You never know what’ll turn up in Kentucky.