OVERFLOW

"Topographic indication of a paleo-basin upstream of the bedrock high"

 For a lake to pond and overspill a bedrock high, the water must be contained within a basin upstream of the bedrock high.  A topographic indication of this paleo-basin is a long lived feature.  Unfortunately, paleo-basins can also occur behind the bedrock high of antecedent and superimposed transverse drainages, for a variety of reasons.  Therefore, this criterion only helps distinguish between piracy and overflow transverse drainages.  Piracy transverse drainages require a paleo-flow direction instead of a paleo-basin.  The upper image highlights a paleo-basin from a physical model and the lower image a paleo-basin from the Salt River, Arizona.