I've visited this spot several times over the last few years and considered placing a cache here on each visit but never had an extra one with me, but this time I cam prepared.
The well here was used for watering stock as herds werd driven through the area. Water levels are generally high during winter but are lower in summer months.
There is off-road parking for up to about 8 4wd's with caravans at GZ. You are looking for a black Bison Tube