In November 1872 George Smith, working through unbaked tablets in the British Museum, found on tablet 11 an account of a flood: a man instructed to build a boat, a vessel grounded on a mountain, birds released to test for dry land. He announced it to the Society of Biblical Archaeology with, by the account of those present, considerable excitement, and the Daily Telegraph funded him to return to Nineveh, where he recovered further fragments. The parallels with the Genesis flood are close enough at the level of episode that borrowing in some direction, or common descent from a shared Mesopotamian tradition, is not seriously disputed, but the Babylonian material is older, and the flood also appears in the Akkadian epic of Atrahasis, where it makes better narrative sense than it does in Gilgamesh.
The important thing about the text is that it is not finished. The epic is reconstructed from many hundreds of fragments in several languages and dialects, from Nineveh, Babylon, Uruk, Ugarit, Megiddo and elsewhere, and substantial passages are still missing or damaged. New pieces continue to appear, from museum storerooms, from unread excavation material, and from the antiquities market.
The best publicised recent case is a large tablet fragment acquired by the Sulaymaniyah Museum in Iraqi Kurdistan and published in 2014 by Farouk Al-Rawi and Andrew George. It supplied around twenty previously unknown lines of tablet 5 and changed the reading of the Cedar Forest: the forest turns out to be described as a noisy, inhabited place full of birds and monkeys, and Enkidu voices regret at what they have destroyed. A text three and a half thousand years old is still, in a limited but real sense, being edited.