First, the date of the global flood:
2252 BC -- layevangelism.com
2304 BC -- Answers in Genesis (+/- 11 years).
2350 BC -- Morris, H. Biblical Creationism. Grand Rapids, MI: Baker Books, 1993.
Second, at that age we are not dealing with "sedimentary rock layers around the world." We are dealing with soils, common dirt.
Those soils contain a lot of evidence about what occurred while they were being laid down, starting with whether they was wind- or water-deposited.
The soils also contain a record of human occupation. That can be dated by multiple methods, including radiocarbon dating. That method has been shown to be quite accurate, and the claims made against it by young earthers have been shown to be inaccurate. Radiocarbon dating is supplemented by a variety of other methods.
In the western US, we have a continuous record of human occupation going back past 10,000 years. The faunal and floral record can be traced back much farther. There are no breaks in this record which would coincide with a global flood.
One telling piece of evidence is the mtDNA (mitochondrial DNA). There is a good record of Native American DNA from prior to 5,000 years, and after 4,000 years. The haplogroups and mutations match.
If there was a flood, then the groups in the western US would have been wiped out, and quickly replaced by other groups. The mtDNA would be distinctly different, before and after. This is not the case. The mtDNA can be traced from its origins in Africa to the New World, by multiple routes. There is no evidence at all that the entire sequence was terminated and replaced from a different source.
Now, there have been some good floods in the western US. The channeled scablands of eastern Washington state came from a series of late Ice Age floods. The boundaries of these events are known, as are the dates. They left a pretty clear signature in the soils. If a global flood had occurred, it would have left a huge signature in the soils, and the dullest of archaeological students would be able to see it. It would be in all the textbooks and in every back yard. There is no such evidence.
If you have any specific comments on this, please let me know. But don't bother with the creationist pages, as most of them are still hung up on fossils and the geological column, when what we are really dealing with are soils.
Civilization first begins to appear about 9-10,000 years ago if orthodox C14 dating is accepted. Human horticultural civilization has its origins in the Armenia-Assyria region that the flood posits as the landing of the Ark, and this also appears to approximate starting point for the spread of the Indo-European and Semitic language groups. Unsurprisingly, the first cities also appear in this region. The flood would have been some time before that 9-10,000 year mark.
I do not accept the chronologies of the Protestant Fundementalists like Morris. I'm a Catholic, not a Protestant fundementalist, and our perspective on these matters differs in a number of areas.
Please see: "The Science of Today and the Problems of Genesis" by Fr. O'Connell for a concise summary of the Catholic position.