Why cover a well with a large stone?

1 Jacob went on his journey and came to the land of the people of the east. 2 As he looked, he saw a well in the field, and behold, three flocks of sheep lying beside it, for out of that well the flocks were watered. The stone on the well’s mouth was large, 3 and when all the flocks were gathered there, the shepherds would roll the stone from the mouth of the well and water the sheep, and put the stone back in its place over the mouth of the well.

Click to expand...

1. It prevented easy access to the water. Supposedly, the stone could only be removed through a group effort.
2. It provided a measure of security. It was an indication of who owned the water.
3. It minimized evaporation by lowering the temperature inside the well.
4. It kept dirt, debris, and animals from falling into and contaminating the water supply.
5. It prevented wind erosion of the mouth of the well.
6. It prevented people from accidentally falling into the well.