Psalms 78:44 KJV

And had turned their rivers into blood; and their floods, that they could not drink.
Psalms 78:44, King James Version

In context

43 How he had wrought his signs in Egypt, and his wonders in the field of Zoan:

44 And had turned their rivers into blood; and their floods, that they could not drink.

45 He sent divers sorts of flies among them, which devoured them; and frogs, which destroyed them.