You're entitled to your opinion what is necessary or not, but the story is what it is. Genesis 7 is the Biblical account of it. I would further point out that not just every living thing that walked the earth died, but every BIRD. How would local flooding in a region kill every bird? Like I said, if you want to write your own account of the Flood, have at it, but it's not the Bible's.
I am simply read the Genesis text here. I did not "write [my] own account of the flood". I am sorry if the Bible does not tell the story you want it to tell.
You seem to assume that whatever people read into the story must be the true intent of the story. I just read the words.
How did the birds die? They probably didn't. They just went away. If you flood a big enough land, birds will fly to the mountains and those that don't will eventually die of exhaustion if they cannot land anywhere.
P.S. Also, the Hebrew is not just "harim", it's "Kal-H'Hariym". That's coming straight from the Masoretic text. The Hebrew specifically qualifies the hariym as not just itty bitty hills, but high ones.
Kal-HaHarim simply means "all the mountains/hills". (There is no "iy" (as in two Yuds) in the word either.)
You have to understand that there are no "high mountains" in the land in question, assuming "high" is read as "as tall as the mountains of Kurdistan". A "high mountain" in the flat land surrounding the Tigris and Euphrates is _not that high_. Can you understand that?
Why do you insist that the story must be read in a way that is physically impossible? Harim can be read as big mountains and as small mounts. Why choose the one that is physically impossible and then claim that the story doesn't make sense.
The harim gavahim mentioned cannot have been particularly high, since they were located in the land and the land was flat. You can verify this using Google Earth if you want. The _high_ mountaisn (in the Alps sense of high mountains) are further away from the rivers and certainly were not flooded (and neither were they part of the land Noah lived in).
If somebody told me they jumped very high yesterday, I could read that as "jumped a few metres high" or "jumped over a house high". But I wouldn't choose the latter and then claim that he must have been lying about jumping high. And neither would I accuse anyone correcting my false assumption of inventing his own story about the event.