I think the flood of Noah was local, and north and also a bit east, of its traditional center in southern Mesopotamia. I also place it earlier than most, at around 4,500 B.C. Of course, I would expect a flood like that to have produced a lot of sediments and have substantial repercussions down river, even if that was not the main area hit.
Sir Leonard Woolley made great excavations in the ancient city of Ur back in the early nineteen thirties. What he found was a layer from the early dynastic period- around 2,700 B.C., and a few lesser things below that. Then he found a 3.75 meter layer of what looked to be flood deposits. Beneath that layer he found artifacts belonging to the Late Ubaid period.
I have seen a number of sources go to great contortions to try and push the date for the flood which laid these sediments up to around 3,000 B.C.. This one even mis-labels the Uruk period as the Ubaid. This source is better and says that the flood deposits at Ur go back to "at least 3,500 B.C." This one is closer still, dating them between 3,600-4,000 B.C. If this deposit was laid by the waters of the flood receding from the mountains then I would say they are not far off, but should look further back still.
The Ubaid period endured for a long time in this region, which was close to its point of origin at Eridu. It lasted from 6,000 B.C. to 3,800 B.C. Even the Wiki article gives a time frame of "4,500-4,000 B.C." as the window for the last phase of this culture. Thus a date of 4,500 B.C. is very consistent with artifacts from the "Late Ubaid Period", which were found directly beneath these deposits. I call for more study on this question from a qualified archaeologist who is not determined to move the date up as so many seem intent on doing.