Extent of fresh water system damage
The current estimate is that the earthquakes damaged 51 kilometres of water supply mains. This excludes those yet to be properly assessed because they are under roads. The damage was far less than it might have been a few years ago because a proactive program was already underway to strengthen the fresh water pipe network.
The February 2011 earthquake seriously cracked the floor of the Huntsbury reservoir. All of its stored water was lost. SCIRT has completed Stage 1 of the rebuild.
There was also structural damage to the Upper Balmoral and McCormack's Bay reservoirs. They can still operate, but will need to be repaired properly in the future.
22 of the 175 fresh water wells were damaged so that they could not be used, and 18 of those were in September. Those were mainly the older and more fragile wells, which is why only a few more were seriously damaged in the 2011 earthquakes. All but 64 wells require some repairs.
The overall effects of the damage have seriously reduced the city water supply system's capacity. Christchurch City Council introduced water restrictions to manage the limited capacity. These were lifted in April 2012.
Chlorine was removed from Christchurch's municipal water supply early in December 2011.