According to this article the sudden upsurge in demand for water storage tanks has seen demand outstrip supply in the Wellington region. In April it was reported that Wellington could be cut off from the water network for three months if a major earthquake struck.
It is estimated each person needs access to at least three litres of drinking water a day. That doesn’t include water for pets, cooking and washing.
At the end of 2013 when it was clear the Rowan-Church & Dougherty water meters were going ahead in Kapiti we installed 2 x 800 litre rainwater fed water tanks, although coming from the roof, drinking it wouldn’t be our preference. The shrubs we planted to hide the tanks now effectively do that.