and the water receded steadily from the earth, and at the end of one hundred and fifty days the water decreased. In the seventh month, on the seventeenth day of the month, the ark rested upon the mountains of Ararat. The water decreased steadily until the tenth month; in the tenth month, on the first day of the month, the tops of the mountains became visible. (Genesis 8:3-5)After 40 days of rain, and 110 more days... in the seventh month, on the seventeenth day of the month (the 600th year of Noah's life) the flood finally reached its maximum height.
The seventeenth day of the seventh month marked the 150th day of the flood— the day that the water stopped prevailing upon the earth (Genesis 7:24). On that day, for the first time since the start of the flood, the water decreased in height (Genesis 8:3). On that day, the ark came to a rest (Genesis 8:4).
Between seventh month, on the seventeenth day of the month (Genesis 8:3) and the the tenth month, on the first day of the month (Genesis 8:5) there elapsed two months and thirteen days (or about 73 days). During these 73 days, the water upon the earth decreased steadily. If the view is taken that the 150 days in Genesis 7:24 do not refer to the first 150 days of the flood, then this is the time period in which the 150 days in Genesis 7:24 come to an end (for more info see Chronology of the Flood: The First 150 Days).
After those 73 days were complete, the water had decreased enough for the mountains to be seen (for more info see How Did Noah's Ark Rest Upon Mountains That Were Not Visible?).
Take a look at the chronology of the flood graphic below in order to see the complete chronology of the flood.
The Chronology of the Flood: The Raven and Dove - Genesis 8:6-12
The First Sight Of The Post-Flood World - Genesis 8:5
How God Stopped The Flood (Part 1) - Genesis 8:1-3
The Ark Comes To A Rest (Part 1) - Genesis 8:4
Evidence for a Global Flood: Water Above The Mountains - Genesis 7:19-20
To view a larger version of this graphic click here.