In TN systems (i.e. neutral bonded to ground on the customer side as seen in the US) local ground rods aren't universally required, so the bonded water pipe could end up being the only electrode even if not designed as one. For any new setups you're likely require to install at least one rod, measuring ground impedance as you go, adding further rods if necessary. New buildings generally have 3x30mm stainless steel (or possibly galvanised) laid into the concrete footings to ensure good grounding. This is usually connected to the main equipotential bonding connector using 10mm steel wire or the same flat steel and then connected to the equipotential bonding bus bar using 16mm2 Cu wire or larger. Anything that could potentially carry lightning currents (antenna bonding, satellite dishes,...) have to be at least 16mm2 too. Water pipe bonds can be as small as 4mm2 I think.
If you have a large setup with multiple transformers you'd likely install additional steel in the footings of the transformer box walls, as far as I know to the same dimensions mentioned above. I am not too familiar with such large systems though.
