Two weeks ago I saw a documentary on a local PBS station on this story. With six weeks to go before flooding a French dig team found a villa on one side of the river. The mosaics are beautiful and were to be displayed in a local museum. The Turkish government did delay the completion of the dam (in the face of all the publicity about the find), but it went ahead. No one knows if other artifacts were there and are now buried under the river/mud.
I was curious as to why the archaeologists only got serious about the dig six weeks before it was scheduled to be flooded.
Oh, and the archaeologists theorized that the villa was burned by barbarians. I was struck by the way these Roman villas were not protected by walls. I suppose they relied on the legions as their "living walls." The town across the river did have walls; it fell as well.
Final point, in spite of its blatant politics, my family and I enjoy the documentaries on PBS very much. Recently we have seen documentaries on the sinking of the General Belgrano and archaeological digs in Afghanistan. I did not care much for last week's "Guns, Germs and Steel." Too much heavy handed, "bad white men" attitude for me to handle.
Perhaps you're thinking of Zeugma? That's not near Istanbul though...
The archaeologists are educated idiots.
Instead of wasting their breath 'pleading', they should have planted some endangered salamanders and jumping mice, then called in the UN biologists.