4. The third bowl 16:4

All the fresh water sources (springs, rivers, lakes, etc.) become blood in this plague (cf. 8:11; Exod. 7:24; Ps. 78:43-44). If the water is literal water, should we not understand the blood as literal blood too? People cannot exist long without any water to drink. However other cataclysmic changes follow that will evidently make water available again (cf. vv. 17-21).