water level meter

We weren’t sure if the water was going to go back down (so that we could resume our family swim day), so I put together a little make-shift water level meter in a calm part of the river. When I started, all ten rocks were high and dry. A few minutes later, the bottom three were much damper.

A few minutes later still and I had to add more rocks:

We decided it was a lost cause for the day after that: