i heard that Noah`s Flood was restricted to a local area, how did God cover the mountains and prevent waters?

The water covered the whole earth. If you read the entire chapter it makes it more understandable. When it says 15 cubits it just means that the top of the mountains were 15 cubits below sea level.

Then the Lord said to Noah, "Go into the ark, you and all your household, for I have seen that you are righteous before me in this generation. Take with you seven pairs of all clean animals, the male and his mate, and a pair of the animals that are not clean, the male and his mate, and seven pairs of the birds of the heavens also, male and female, to keep their offspring alive on the face of all the earth. For in seven days I will send rain on the earth forty days and forty nights, and every living thing that I have made I will blot out from the face of the ground." And Noah did all that the Lord had commanded him. Noah was six hundred years old when the flood of waters came upon the earth. And Noah and his sons and his wife and his sons' wives with him went into the ark to escape the waters of the flood. Of clean animals, and of animals that are not clean, and of birds, and of everything that creeps on the ground, two and two, male and female, went into the ark with Noah, as God had commanded Noah. And after seven days the waters of the flood came upon the earth. In the six hundredth year of Noah's life, in the second month, on the seventeenth day of the month, on that day all the fountains of the great deep burst forth, and the windows of the heavens were opened. And rain fell upon the earth forty days and forty nights. On the very same day Noah and his sons, Shem and Ham and Japheth, and Noah's wife and the three wives of his sons with them entered the ark, they and every beast, according to its kind, and all the livestock according to their kinds, and every creeping thing that creeps on the earth, according to its kind, and every bird, according to its kind, every winged creature. They went into the ark with Noah, two and two of all flesh in which there was the breath of life. And those that entered, male and female of all flesh, went in as God had commanded him. And the Lord shut him in. The flood continued forty days on the earth. The waters increased and bore up the ark, and it rose high above the earth. The waters prevailed and increased greatly on the earth, and the ark floated on the face of the waters. And the waters prevailed so mightily on the earth that all the high mountains under the whole heaven were covered. The waters prevailed above the mountains, covering them fifteen cubits deep. And all flesh died that moved on the earth, birds, livestock, beasts, all swarming creatures that swarm on the earth, and all mankind. Everything on the dry land in whose nostrils was the breath of life died. He blotted out every living thing that was on the face of the ground, man and animals and creeping things and birds of the heavens. They were blotted out from the earth. Only Noah was left, and those who were with him in the ark. And the waters prevailed on the earth 150 days. (Genesis 7:1-24 ESV)

I'm willing to bet that any land mass has been under water at some point during Earth's lifetime due to tectonic movement and to some degree, glaciation. As far as the religious texts go, the story of Noah and anyone like him is based on a collation of legends and tales, some of which may have a little truth to them. It is impossible to cover the Earth entirely with water, given the most generous estimate of what water exists on the planet at this time. Now many could argue that anything is possible and I'd have to agree, but I would say that it is rather unlikely that Earth could have obtained that much water to support the story and then lose enough that would support current estimates of what we have now. The criteria can be subjective depending on what you are trying to consider a flood to be. No doubt someone, somewhere has declared what a flood is in official terms, but it can mean different things to different people.

The floodwaters were 15 cubits above the tops of the high mountains. The Bible tells us that the fountains of the deep were opened up, which more than likely is what supplied the majority of the water to the surface of the earth. The atmosphere was also different than that of today since there was some type of vapor canopy that held a lot of moisture; it never rained on the ground but rather the atmosphere watered the earth with a mist.

When God's judgment comes for you, will you be ready? Imagine, all those people beating on the side of the Ark screaming for the door to be opened only to drown because it was too late for them to make the right decision.

Please beware of false prophet and fals doctrines. Do not walk their part of deceit and destruction.

Noah's flood covered the whole world. The bible means what it said. It rained 40 days and 40 nights in the whole world.

Little rains in some parts of some countries used to cause heavy floods, talkless of a rain that fall all over the world for 40 DAYS AND NIGHTS {One month 10 days} non-stop. How long will it take for a man to climb the highest mountain?

"Fifteen cubits upward did the waters prevail; and the mountains were covered."

I don't think so.

God covered the mountains with fluffy clouds and hoped that people were so preoccupied with their world disappearing under the waves that they wouldn't notice.

Those are not mountains at 15 cubits. Taking a generous cubit of 21 inches that is 26.25 feet. Not even a good sized hill.

naysayers overlook that fact

water seeks its own level

if the Middle East was flooded then the whole world would be flooded.

He had a group of engineers from upstate New York design a dam.

ERRRR................... Don't you know many of us have faith there are unicorns like in the bible? Don't you know anything. You should respect other people beliefs. Religious people live in a bizarre and superstitious world you should admire them.

A big pondliner!