With water? Unlikely. Water doesn't just drop and disappear on the same spot in the middle of nowhere, it tends to move downstream, into places that are in the

With water? Unlikely. Water doesn't just drop and disappear on the same spot in the middle of nowhere, it tends to move downstream, into places that are in the middle of somewhere - as we have seen with the Mississippi watershed: first Out In Nowhere, IN, then ORCS, then Lake Ponchartrain. A 500y water event in nowhere land would still propagate; the speed of water release from the drop point (sorry for not using the correct jargon) would mean the difference between a 10y event downstream or a 500y event on the go.