The Whyalla Levee cache series follows the line of a Levee bank that protects the western edge of Whyalla from surface run-off in the event of a major rain event. Such an event occurred in January 2007 when 85mm fell in an hour, following a 40mm deluge the day before.
The levee was built after massive storms in 1971 caused flooding to the new developments in Whyalla Stuart. In 1973, 2 weeks after Stuart High School was opened, it was flooded as the levee had not extended that far yet. It is now approx 4 km long.
This cache is at the northern end of the levee, and as water flows from the north when it floods, I’ve called this the start! (GZ is a few metres from the start due a nearby cache.)