Well then, let me include some equal sites on proof that it didn't happen, and I'll try proving them wrong.
"God would not massacre everyone."Proof: The verses on this site do not show the rest of the context. The people were being punished.
"God senselessly murdered millions of humans and billions of animals in the flood."
My retort: Genesis 6:1-8
http://www.biblicalnonsense.com/chapter6.html"we have a god who has to modify virtually all of his creations for the solely expressed reason of the people having become wicked and evil (Genesis 6:5), yet wicked and evil people continue to exist throughout the Bible."
My retort: Genesis 3:1-24
"A little known but important piece of information about the Genesis flood is that the extremely similar Epic of Gilgamesh in the Sumerian legend predates Noah’s story by at least one thousand years in the written form and at least five hundred years for the setting."
My retort:
The Epic of Gilgamesh contains parts of the Flood from how other people viewed it. It was written by the pagan Mesopotamians if I remember right. Noah's Ark is how Christians relate to it. There are other stories too, such as that of Sargon (also Mesopotamia). Similar stories come from Hawaii, Australasia, China, old England, etc. Look at it as Noah's Ark originated from the Flood itself, along with all the other stories, it really seems that a Great Flood did in fact happen (otherwise, how would stories originate from all over the world with no means of international communication).
"The amount necessary to produce a flood of global proportions far exceeds the current amount available on, in, and above the earth."
I already explained this^
"One should also realistically expect at least a scant amount of geological or natural evidence for a global flood if the supernatural catastrophe took place, but the signs overwhelmingly point to the contrary."
Explained this too, the Pacific Rift Valley and Mid-Atlantic Ridge don't look like catastrophes now, but they probably caused the flood when the Pacific's floor caved in.
“How did Noah get all those animals to fit on the ark?”
My retort: Back thousands of years ago, there was not as much animal diversity (as in not as many breeds of different animals, since there was scant enough time for inter-breeding to occur that far back in the planet's history)
" The seemingly immune marine life could have fared no better than their terrestrial counterparts because, first of all, the rapid mixture of salt and fresh water from the conglomeration of various pure water sources would have killed all known marine creatures in a matter of hours. End of story."
Retort: A lot of marine life WAS wiped out. Also, the concentration of all these substances would have been much lower in so much water.
" The world’s vegetation should also join the growing list of organisms without immunity from the effects of the morally shameful flood."
Retort: A lot of plants DID go extinct. Seeds that survived the flood or could go dormant after buried under sediment would have survived the flood.
" It’s painfully obvious that the story is burdened with a number of significant problems. For this reason, many apologists will attempt a hopeless defense for it by suggesting that the tale was speaking of a local flood."
Retort: How would a local flood be that deep? How would stories originate all over the planet?
Before telling me what I didn't point out, I only covered what I thought were major points of how the flood could NOT exist.