To educate and encourage folk not to waste water is fair enough, but it seems a shame to have all that water in the river, yet not have all that we need.
Compared with other cities, the Waikato River puts Hamilton in an enviable position with an almost unlimited source of water.
We should make the most of it and adopt an "all you need" policy. We should never have restrictions. This, of course, will take time (resource consent, red tape, etc) and money (to upgrade treatment facilities). Some upgrading must already be budgeted for to cope with growth.
Reserve capacity would also be prudent in case of an extended drought or a 100-year event, but, most importantly, any thoughts of water metering and its associated costs to ratepayers could be well and truly put to bed.