Below are the narratives found in the Qur’an pertaining to Nuh (عليه السلام):
I had certainly sent Noah to his people, and he said, “O my people, worship Allah; you have no deity other than Him. Indeed, I fear for you the punishment of a tremendous Day. The eminent among his people said, “Indeed, we see you in clear error.” [Noah] said, “O my people, there is not error in me, but I am a messenger from the Lord of the worlds.” I convey to you the messages of my Lord and advise you; and I know from Allah what you do not know. Then do you wonder that there has come to you a reminder from your Lord through a man from among you, that he may warn you and that you may fear Allah so you might receive mercy.” But they denied him, so I saved him and those who were with him in the ship. And I drowned those who denied My signs. Indeed, they were a blind people. [Q7:59-64]
From the above passage we are not clear whether the flood was global or local. We are told that those who denied Nuh (عليه السلام) were drowned and those who believed him were saved in the ship. According to the verse, those who did not deny him were not drowned. Let us look further:
And I had certainly sent Noah to his people, [saying], “Indeed, I am to you a clear warner that you not worship except Allah. Indeed, I fear for you the punishment of a painful day.” So the eminent among those who disbelieved from his people said, “We do not see you but as a man like ourselves, and we do not see you followed except by those who are the lowest of us [and] at first suggestion. And we do not see in you over us any merit; rather, we think you are liars.” He said, “O my people have you considered: if I should be upon clear evidence from my Lord while He has given me mercy from Himself but it has been made unapparent to you, should we force it upon you while you are averse to it? And O my people, I ask not of you for it any wealth. My reward is not but from Allah. And I am not one to drive away those who have believed. Indeed, they will meet their Lord, but I see that you are a people behaving ignorantly. And O my people, who would protect me from Allah if I drove them away? Then will you not be reminded? And I do not tell you that I have the depositories [containing the provision] of Allah or that I know the unseen, nor do I tell you that I am an angel, nor do I say of those upon whom your eyes look down that Allah will never grant them any good. Allah is most knowing of what is within their souls. Indeed, I would then be among the wrongdoers.” They said, “O Noah, you have disputed us and been frequent in dispute of us. So bring us what you threaten us, if you should be of the truthful.” He said, “Allah will only bring it to you if He wills, and you will not cause [Him] failure. And my advice will not benefit you – although I wished to advise you – If Allah should intend to put you in error. He is your Lord, and to Him you will be returned.” Or do they say [about Prophet Muhammad], “He invented it”? Say, “If I have invented it, then upon me is [the consequence of] my crime; but I am innocent of what [crimes] you commit.” And it was revealed to Noah that, “No one will believe from your people except those who have already believed, so do not be distressed by what they have been doing. And construct the ship under My observation and My inspiration and do not address Me concerning those who have wronged; indeed, they are [to be] drowned.” And he constructed the ship, and whenever an assembly of the eminent of his people passed by him, they ridiculed him. He said, “If you ridicule us, then we will ridicule you just as you ridicule. And you are going to know who will get a punishment that will disgrace him [on earth] and upon whom will descend an enduring punishment [in the Hereafter].” [So it was], until when My command came and the oven overflowed, I said, “Load upon the ship of each [creature] two mates and your family, except those about whom the word has preceded, and [include] whoever has believed.” But none had believed with him, except a few. And [Noah] said, “Embark therein; in the name of Allah is its course and its anchorage. Indeed, my Lord is Forgiving and Merciful.” And it sailed with them through waves like mountains, and Noah called to his son who was apart [from them], “O my son, come aboard with us and be not with the disbelievers.” [But] he said, “I will take refuge on a mountain to protect me from the water.” [Noah] said, “There is no protector today from the decree of Allah, except for whom He gives mercy.” And the waves came between them, and he was among the drowned. And it was said, “O earth, swallow your water, and O sky, withhold [your rain].” And the water subsided, and the matter was accomplished, and the ship came to rest on the [mountain of] Jūdiyy. And it was said, “Away with the wrongdoing people.” And Noah called to his Lord and said, “My Lord, indeed my son is of my family; and indeed, Your promise is true; and You are the most just of judges!” He said, “O Noah, indeed he is not of your family; indeed, he is [one whose] work was other than righteous, so ask Me not for that about which you have no knowledge. Indeed, I advise you, lest you be among the ignorant.” [Noah] said, “My Lord, I seek refuge in You from asking that of which I have no knowledge. And unless You forgive me and have mercy upon me, I will be among the losers.” It was said, “O Noah, disembark in security from Us and blessings upon you and upon nations [descending] from those with you. But other nations [of them] I will grant enjoyment; then there will touch them from Us a painful punishment.” [Q.11:25-48]
Here we see that Allah (ﷻ) mentions to Nuh (عليه السلام), ‘No one will believe from your people except those who have already believed’, indicating that the disbelievers were all from the nation of Nuh (عليه السلام) and only the disbelievers were drowned.
Nuh (عليه السلام) was then told to get on the ship/boat with his family, the believers (who were very few), and two of each animal. This may indicate that every animal was to be gathered and hence, the flood has to be global; however, this is not necessary. Allah (ﷻ) could have instructed him to gather the animals that were in his area or were his own. The every animal in the verse is not necessarily all-encompassing as some land animals can survive well in water as well. Hence, one must be careful when interpreting every very openly here.
When the ship/boat started sailing upon waves like mountains, Nuh (عليه السلام) could see his son and called out to him to join him but he responded that he would take refuge on a mountain. This shows that the waves of the sea were very high and their like mountains do not mean that they were as high as the tall mountains but that they resembled mountains in shape when they developed and flowed.
The resting of the boat/ship on mountain of Jūdiyy may give one an impression that the waves were very high and reached on mountain tops. However, there are two points to note here – 1) the Qur’an does not mention the height of the mountain, and 2) it does not mention that the boat/ship landed on top of the mountain and it could be even fifty or hundred feet or any other level above the ground. One may climb a mountain but not go all the way to the top and may end the adventure somewhere in between; similarly, the boat/ship could have stopped somewhere near the foot of the mountain.
The ship could have landed on the mountain on a place something like this (as pointed by the red arrow) or higher or lower.
All this would indicate that the flood was local in nature. However, let us carry on with the text.
And I had certainly sent Noah to his people, and he said, “O my people, worship Allah; you have no deity other than Him; then will you not fear Him?” But the eminent among those who disbelieved from his people said, “This is not but a man like yourselves who wishes to take precedence over you; and if Allah had willed [to send a messenger], He would have sent down angels. We have not heard of this among our forefathers. He is not but a man possessed with madness, so wait concerning him for a time.” [Noah] said, “My Lord, support me because they have denied me.” So I inspired to him, “Construct the ship under My observation, and My inspiration, and when My command comes and the oven overflows, put into the ship from each [creature] two mates and your family, except those for whom the decree [of destruction] has proceeded. And do not address Me concerning those who have wronged; indeed, they are to be drowned. And when you have boarded the ship, you and those with you, then say, ‘Praise to Allah who has saved us form the wrongdoing people.’ And say, ‘My Lord, let me land at a blessed landing place, and You are the best to accommodate [us].’ ”Indeed in that are signs, and indeed, I am ever testing [My servants]. Then I produced after them a generation of others. [Q.23:23-31]
This particular passage is similar to the one before and the lessons learnt from it are similar as well. Even from it, we get the impression that the flood may have been local instead of global. However, let us continue reading:
And I certainly sent Noah to his people, and he remained among them a thousand years minus fifty years, and the flood seized them while they were wrongdoers. But I saved him and the companions of the ship, and I made it a sign for the worlds. [Q.29:14-15]
Nuh (عليه السلام) being a sign for the world may indicate that the flood was global; however, it is not decisive because Isa (عليه السلام) and his mother have also been called as signs for all peoples (Q.21:91) yet he was sent only to Bani Israel. Another passage below reads as follows:
Indeed, I sent Noah to his people, [saying], “Warn your people before there comes to them a painful punishment.” He said, “O my people, indeed I am to you a clear warner, [Saying], ‘Worship Allah, fear Him and obey me. Allah will forgive you of your sins and delay you for a specified term. Indeed, the time [set by] Allah, when it comes, will not be delayed, if you only knew.’ ” He said, “My Lord, indeed I invited my people [to truth] night and day. But my invitation increased them not except in flight. And indeed, every time I invited them that You may forgive them, they put their fingers in their ears, covered themselves with their garments, persisted, and were arrogant with [great] arrogance. Then I invited them publicly. Then I announced to them and [also] confided to them secretly. And said, ‘Ask forgiveness of your Lord. Indeed, He is ever a Perpetual Forgiver. He will send [rain from] the sky upon you in [continuing] showers and give you increase in wealth and children and provide for you gardens and provide for you rivers. What is [the matter] with you that you do not attribute to Allah [due] grandeur while He has created you in stages? Do you not consider how Allah has created seven heavens in layers and made the moon therein a [reflected] light and made the sun a burning lamp? And Allah has caused you to grow from the earth a [progressive] growth. Then He will return you into it and extract you [another] extraction. And Allah has made for you the earth an expanse. That you may follow therein roads of passage.’ “Noah said, “My Lord, indeed they have disobeyed me and followed him whose wealth and children will not increase him except in loss. And they conspired an immense conspiracy. And said, ‘Never leave your gods and never leave Wadd or Suwa‘ or Yaghūth and Ya‘ūq and Nasr. And already they have misled many. And, [my Lord], do not increase the wrongdoers except in error.” Because of their sins they were drowned and put into the Fire, and they found not for themselves besides Allah [any] helpers. And Noah said, “My Lord, do not leave upon the earth from among the disbelievers an inhabitant. Indeed, if You leave them, they will mislead Your servants and not beget except [every] wicked one and [confirmed] disbeliever. My Lord, forgive me and my parents and whoever enters my house a believer and the believing men and believing women. And do not increase the wrongdoers except in destruction.” [Q.71:1-28]
Earlier, and here as well, we see that Allah (ﷻ) refers to the people as his people i.e. people of Nuh (عليه السلام) whereas here we see that Nuh (عليه السلام) prayed to Allah (ﷻ) to not leave upon the earth from among the disbelievers an inhabitant. From what is apparent is that Nuh (عليه السلام) prayed for the destruction of every disbeliever on earth. This goes to show us that his people were the entirety of the people of earth and they were more or less based in the same locality not far from each other or this could mean that all the disbelievers during his time were from his nation only and other nations, if any, were believers. On the other hand, do not leave upon the earth may not necessarily mean the entire earth because we see in Q.2:11 that the hypocrites of Madina were told to not create chaos on the earth (ard) whereas it did not mean the entire earth. Ard does not only mean earth but also means land. Hence, the prayer of Nuh (عليه السلام) could be to punish all the disbelievers on the land that he was on.
Mankind started from Adam and Hawwa and was initially not as spread out as it is today. Nuh (عليه السلام) and his people were based in a certain location from where the disbelievers were destroyed and only the believers remained. Alternatively, it could be that there were other people and nations on earth but they had not disbelieved and hence were not affected by the flood; this way, the message of Nuh (عليه السلام) would not be for them as they were believers and would have had their own prophets later down the line. Hence, the flood of Nuh (عليه السلام) could be both global and local in the sense that it covered entire humanity of the time killing every disbeliever of the time while not affecting the entire planet earth as the disbelievers were located centrally in one nation. Allah (ﷻ) does not punish anyone unjustly as He says in the Qur’an:
وَمَا كُنَّا مُعَذِّبِينَ حَتَّى نَبْعَثَ رَسُولاً
And never would I punish until I sent a messenger [Q.17:15].
تَكَادُ تَمَيَّزُ مِنَ الغَيْظِ كُلَّمَا أُلْقِىَ فِيهَا فَوْجٌ سَأَلَهُمْ خَزَنَتُهَآ أَلَمْ يَأْتِكُمْ نَذِيرٌ – قَالُواْ بَلَى قَدْ جَآءَنَا نَذِيرٌ فَكَذَّبْنَا وَقُلْنَا مَا نَزَّلَ اللَّهُ مِن شَىْءٍ إِنْ أَنتُمْ إِلاَّ فِى ضَلَـلٍ كَبِيرٍ
It (i.e. hell) almost bursts with rage. Every time a company is thrown into it, its keepers ask them, “Did there not come to you a warner?” They will say,” Yes, a warner had come to us, but we denied and said, ‘Allah has not sent down anything. You are not but in great error.’ “
وَسِيقَ الَّذِينَ كَـفَرُواْ إِلَى جَهَنَّمَ زُمَراً حَتَّى إِذَا جَآءُوهَا فُتِحَتْ أَبْوَبُهَا وَقَالَ لَهُمْ خَزَنَتُهَآ أَلَمْ يَأْتِكُمْ رُسُلٌ مِّنكُمْ يَتْلُونَ عَلَيْكُمْ ءَايَـتِ رَبِّكُمْ وَيُنذِرُونَكُمْ لِقَـآءَ يَوْمِكُمْ هَـذَا قَالُواْ بَلَى وَلَـكِنْ حَقَّتْ كَلِمَةُ الْعَذَابِ عَلَى الْكَـفِرِينَ
And those who disbelieved will be driven to Hell in groups until, when they reach it, its gates are opened and its keepers will say, “Did there not come to you messengers from yourselves, reciting to you the verses of your Lord and warning you of the meeting of this Day of yours?” They will say, “Yes, but the word of punishment has come into effect upon the disbelievers [Q.3:71].
وَهُمْ يَصْطَرِخُونَ فِيهَا رَبَّنَآ أَخْرِجْنَا نَعْمَلْ صَـلِحاً غَيْرَ الَّذِى كُـنَّا نَعْمَلُ أَوَلَمْ نُعَمِّرْكُمْ مَّا يَتَذَكَّرُ فِيهِ مَن تَذَكَّرَ وَجَآءَكُمُ النَّذِيرُ فَذُوقُواْ فَمَا لِلظَّـلِمِينَ مِن نَّصِيرٍ
And they will cry out therein, “Our Lord, remove us; we will do righteousness – other than what we were doing!” But did I not grant you life enough for whoever would remember therein to remember, and the warner had come to you? So taste [the punishment], for there is not for the wrongdoers any helper [Q.35:37].
From the Qur’an we learn that Allah (ﷻ) does not punish people without sending warners to them; the people destroyed are provided ample opportunities to mend their ways before they are punished. Hence, we come to the conclusion that either the entirety of mankind was settled where Nuh (عليه السلام) was based or that the only disbelievers on the earth at the time were from his people who were destroyed.
The Qur’an differs from the Bible
Plenty of misconceptions arise due to reliance on the Bible and some Muslims subconsciously do that as well. One of the purposes of the Qur’an is to correct what the previous scriptures got wrong i.e. what the people changed in them resulting in those books to become altered, corrupt, and eventually man-made.
Muslims do not believe in 6,000 or 10,000 year old humanity. Consider the following Hadith:
لَمَّا خَلَقَ اللَّهُ آدَمَ مَسَحَ ظَهْرَهُ فَسَقَطَ مِنْ ظَهْرِهِ كُلُّ نَسَمَةٍ هُوَ خَالِقُهَا مِنْ ذُرِّيَّتِهِ إِلَى يَوْمِ الْقِيَامَةِ وَجَعَلَ بَيْنَ عَيْنَىْ كُلِّ إِنْسَانٍ مِنْهُمْ وَبِيصًا مِنْ نُورٍ ثُمَّ عَرَضَهُمْ عَلَى آدَمَ فَقَالَ أَىْ رَبِّ مَنْ هَؤُلاَءِ قَالَ هَؤُلاَءِ ذُرِّيَّتُكَ فَرَأَى رَجُلاً مِنْهُمْ فَأَعْجَبَهُ وَبِيصُ مَا بَيْنَ عَيْنَيْهِ فَقَالَ أَىْ رَبِّ مَنْ هَذَا فَقَالَ هَذَا رَجُلٌ مِنْ آخِرِ الأُمَمِ مِنْ ذُرِّيَّتِكَ يُقَالُ لَهُ دَاوُدُ
“When Allah created Adam He wiped his back and every person that He created among his offspring until the Day of Resurrection fell out of his back. He placed a ray of light between the eyes of every person. Then He showed them to Adam and he said: ‘O Lord! Who are these people?’ He said: ‘These are your offspring.’ He saw one of them whose ray between his eyes amazed him, so he said: ‘O Lord! Who is this?’ He said: ‘This is a man from the latter nations of your offspring called Da’ood [Tirmizi vol. 5, book 44, Hadith 3076].
In a 6,000 year old civilization, Da’ood (عليه السلام) can never be from the latter nations. However, if the civilization is 40,000 years old or 200,000 or even 500,000 years old, then he does fall under the latter nations. There is nothing in the Qur’an or the Hadiths that ask us to believe in a civilization of a few thousand years. Moreover, the Qur’an, being a book of guidance and not being a story book, does not go into unnecessary details such as dates and times, who married whom and how many wives and children he had and so on. Therefore, we do not know whether Nuh (عليه السلام) lived 40,000 or 200,000 years ago, for instance. What we do know is that he called out to his people, who were either the entire human population of earth at the time or were the only disbelievers at the time and those who disbelieved him were destroyed by the flood.
Does this mean that Nuh (عليه السلام) was sent for entire mankind and if so, that contradicts Islamic teachings as only Prophet Muhammad (ﷺ) was sent for entire mankind?
When a prophet is sent to his people, he is to be obeyed by them. In the case of Nuh (عليه السلام), his people, if they were the only people on earth, were just like in the case of Adam (عليه السلام) where he and his children were the only people on the earth at the time. Alternatively, it could also be that there were other people and nations on earth but they had not disbelieved and hence were not affected by the flood; this way, the message of Nuh (عليه السلام) would not be for them as they were believers and would have had their own prophets later down the line. Hence, this does not contradict the fact that the Prophet (ﷺ) was sent for all mankind, which is scattered and diverse.
The story of Noah and the flood is clearly established by the Qur’ān as being an event that took place early in the prophetic history of Adam’s descendants. There is no conclusive evidence in the Qur’ān or the Sunnah regarding the geographical extent of the flood or how much of the total human population were affected. What is clear from the texts is that all of Noah’s people who remained behind perished in the flood and that the Children of Israel and all of the prophets whose names are mentioned in the Qur’ān are from the descendants of those who boarded the Ark.
Indeed, Allah knows best.
References and footnotes:
 In Sahih al-Bukhari book 37, Hadith 3, we find the following narration:
” مَا بَعَثَ اللَّهُ نَبِيًّا إِلاَّ رَعَى الْغَنَمَ ”. فَقَالَ أَصْحَابُهُ وَأَنْتَ فَقَالَ ” نَعَمْ كُنْتُ أَرْعَاهَا عَلَى قَرَارِيطَ لأَهْلِ مَكَّةَ ”
“Allah did not send any prophet but shepherded sheep.” His companions asked him, “Did you do the same?” The Prophet (ﷺ) replied, “Yes, I used to shepherd the sheep of the people of Mecca for some Qirats.”
We know from this that Nuh (عليه السلام) had also herded at some time in his life and hence, the instruction of Allah (ﷻ) to gather the animals in pairs could be for the purpose of future economic well-being of Nuh (عليه السلام) and his people and not that just like mankind was saved, animal kind also required saving. Allah knows best.
This hypothesis is backed up by another Hadith (Sahih al-Bukhari book 60, Hadith 131) where Allah (ﷻ) grants pregnant animals to three people after which their property grows many-folds. The purpose of loading the animals in pairs on board the ship/boat could be the same. Allah knows best.
 Recommended reading: Excellent article series on Noah’s Flood and the Qur’an