Revelation 16:4
And the third angel poured out his vial upon the rivers and fountains of waters; and they became blood.
Cross-references
Revelation 16:5
Parallel
In Rev 16:5, the angel of the waters declares God's justice for turning water to blood, directly responding to this bowl.
Revelation 8:11
Parallel
Rev 8:11 also affects rivers and springs with a third trumpet judgment, but turns them bitter rather than blood.
Exodus 7:20
Typology
Ex 7:20 records the first plague turning Nile to blood, directly prefiguring this end-time judgment on water.