What does the Bible say about why God sent the flood?

In Genesis 6:5-7, it is stated that God saw the wickedness of man was great, and every imagination of his heart was only evil continually. This pervasive evil grieved God in His heart, leading to His decision to send the flood. It's important to note that God was not surprised by man’s sin; rather, He had knowledge of it from eternity and had already chosen a people to save. The flood serves as a critical moment in God's redemptive narrative, illustrating His judgment against sin while simultaneously establishing a covenant with Noah, symbolizing hope for those chosen by Him.