We have a nice man made lake in Winston-Salem NC, called Salem Lake. There is a walking/biking trail around it, about 7 miles long and a lot of people use it daily for their exercise. The original damn was getting old and a few years back city decided to replace it with a new damn. It took them about one extra year to replace it than was originally advertised, but it is back now and lake at its full level.
I took this photo couple years ago about one month or so after they drained the lake. The surface was all clay like slimy dirt, and it broke into this shapes, similar to what you see in some deserts after they have rain. Walking on it was very tricky as it was a bit soft and if I applied to much pressure, the clay was giving up and my shoe was going into it, not something I wanted to do. And yeah, those cans grabbed my attention from the trail above the lake, I think that is why I climbed down to the bottom of it, to take this photo.
A few weeks later this whole area was overgrown by wild vegetation and it was like that until they filled it back with water. Those cans might very well still be down there, waiting to be discovered by archeologists a few thousand years from now.