I believe the example I gave might have caused some confusion. I would partition the appropriate government authorities and recommend that if a formal excavation could not be curried out before the water touches the papyri than they should consider a less formal dig. This might include allowing of the poor to be rewarded for digging up and bringing the papyri in for an award. Depending on the circumstances, the authorities might even allow them to keep some of the artifacts for resell, provided that they are registered. It would of course be the decision of that countries authorities if my recommendation should be acted upon.
Archaeologists often talk is if a site is hermetically sealed until excavation takes place.
This is very rarely the case. As for artifacts loosing all their value if not discovered by archaeologists that depends on the artifact. A scroll might tell you a great deal about a culture even if the find spot is not known. Sincerely Yours, John Deaton. But the coins, and the olive pits, and the DNA in the lice on the combs might tell you more.