The Hebrew word אָרֶץ (erets) can mean "earth", "land", or "ground" (Strongs H776). For example, in Genesis 2:13, the river Gihon winds through the whole land (אָרֶץ) of Cush.
This word, אָרֶץ, is used throughout the flood account, where all major English translations take the account to be referring to the whole earth.
E.g., Gen 7:24:
The waters flooded the earth for a hundred and fifty days. (NIV)
And the waters prevailed on the earth 150 days. (ESV)
And the floodwaters covered the earth for 150 days. (NLT)
Since Bible translators are highly educated and all the major English translations seem to agree on this point, I assume there must be clear indications in the text that the author of the passage intended the flood to be understood as covering the whole earth rather than the whole land.
What are the compelling indications in the text itself that this is how the word אָרֶץ should be translated in this passage?
Note: I am not asking for scientific or theological arguments about the interpretation of this passage, but for arguments from this text itself.