Genesis 8:5

and the waters have been going and becoming lacking till the tenth month; in the tenth month, on the first of the month, appeared the heads of the mountains.

Genesis 7:11

In the six hundredth year of the life of Noah, in the second month, in the seventeenth day of the month, in this day have been broken up all fountains of the great deep, and the net-work of the heavens hath been 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 the life of Noah, in the second month, in the seventeenth day of the month, in this day have been broken up all fountains of the great deep, and the net-work of the heavens hath been opened,