Not very deep, the pool was fed by a waterfall just below a pond. Several 2-3 inch bluegill had washed downstream and were trapped in a relatively confined area. Laying on the bottom, the water snake was virtually invisible and it made several attempts to nap a passing bluegill. It didn't take too long for "Bob" the water snake (named by school kids last year) to catch a meal.
The water snake brought his catch into an area surrounded by roots, sticks, and leaves where the fish, even if it escaped, would be trapped and the water snake would be hidden from its own predators. A leisurely meal followed as the snake prepared to eat what was indeed a big gulp.