This Australian company makes more than transportable concrete water tanks: chemical storage, outside toilet and shower blocks, office or granny flats, and offers concrete tank renovation. In comparison with the concrete tank that has to be made on site with the attendant problems that entails Williams deliver a ready made unit to your property.
Having seen what can happen to plasti tanks exposed to wild fire and the spectacular spontaneous falling apart of the fit together kind, I wanted something more robust to hold 5,000 gallons.

Although I live in Victoria I had to turn to South Australia to get a concrete tank.
I made enquiries and arrangements by phone. Payment was straightforward enough and Williams supplied a concrete tank on time and installed fine, just as promised.
However, there was a leak. I did not want to interfere with the product and thereby possibly lose any claim for restitution so I telephoned the company. Some too-ing and fro-ing followed which was a bit annoying, but in the end I was promised someone would come to take a look. The hitch being that the someone had to be in the vicinity, and, as you know I am in Victoria and they are operating out of South Australia. In addition I was to empty the tank before he arrived so he could deal with whatever had to be done. I had to empty what water I had gained a couple of times before some turned up. My trees were happy. I was not so pleased especially when I had to miss an outing for which I had paid ahead in order to meet with the fellow.
He pronounced that the bottom outlet hadn't been fitted properly and all that needed to be done to fix it was to unscrew, wrap plumbing tape on the thread, and put it back. Simple. Did he bring tools or tape? Nooooo...
So, he came all the way from SA to inspect a leak unprepared to carry out even a minor repair. Hmmm.
Being half way competent myself I did what he described, having gained his okay to do so I had to assume it would not affect any warranty. Thank goodness I have not had to find out. The ill fitting tap has been the only problem.
Other than this little hurdle the tank has been just what I wanted and lived up to expectations.