With the upper part of the Tutaenui reservoir walking track being opened mid last year I've been scoping out a new cache hiding spot to extend the walk. An extra 10 minutes on the existing trail should have you ready to step off the new boardwalk and approach GZ, may be wet underfoot at times.
Please tuck the 200ml systema back into place once found and signed, it's wedged in snugly. Plenty of bird life to admire too, if that's your thing.