Still hunting for the missing python:
"Once she saw evidence of the recreant reptile's progress in his distinctive trail across a spread of fine sand in the arroyo. The living water was bound to lure him; he could not be far away."

A dry stream bed that has water only very infrequently after it rains heavily in high places which may be far away.
I learned this word during a study period in my home room,where the teacher of Spanish told about as a small girl with her prospector father going along an arroyo, with their burro laden with equipment. Suddenly her father grabbed her and ran to the top of the bank at top speed. Just as they got to the top, a wall of water travelling extremely rapidly came roaring by. Miss Todd didn't say so, but my guess is it was the burro who first sensed the danger.