Genesis 8:5

The waters continued to decrease until the tenth month; on the first day of the tenth month the tops of the mountains were seen.

Genesis 7:11

In the six hundredth year of Noah’s life, on the seventeenth day of the second month, on that same day all the fountains of the great deep [subterranean waters] burst open, and the windows and floodgates of the heavens were opened.

Treasury of Scripture Knowledge

Summary

And the waters decreased continually until the tenth month: in the tenth month, on the first day of the month, were the tops of the mountains seen.

Decreased continually

Bible References

Decreased continually

Genesis 7:11
In the six hundredth year of Noah’s life, on the seventeenth day of the second month, on that same day all the fountains of the great deep [subterranean waters] burst open, and the windows and floodgates of the heavens were opened.