The 30 September earthquake triggered the fail-safe devices on the city’s main reservoirs, says Council operations and maintenance manager Mike Bourke. Valves on the reservoirs are designed to close in a major earthquake until inspections can confirm that the pipelines feeding the city from the reservoirs have not suffered any major damage.

“This earthquake was the first of sufficient magnitude to activate this automatic system, which is there to make sure the water stored in the reservoirs isn’t lost,” Mr Bourke says. “It’s pleasing that the system wasable to be tested in a real situation and that it worked as designed.”

The shut-off valves are among several measures to help protect the city’s assets in a disaster and to conserve precious drinking water. Other measures enable swift restoration of services, but Mr Bourke warns that in a major event people should be prepared to be self-sufficient for at least several days.