We are either experiencing the turtles leaving the small pond to lay their clutch of eggs or for another reason. It is later than normal for them to be laying eggs, but they just might be doing it towards the end of the season; but maybe it is for another reason.
The only other normal reason to see these big snapping turtles moving out of the water is that they are leaving the pond and looking for a better home … like the bigger pond. The turtles will do this for environmental reasons: like it has gotten too crowded for the number of turtles vs. the food supply. The pond has been in great stress these last few years due to low water because it is filling in. Has this reduced the food supply?