Built: • Structures are often targeted or at least collateral damage during an attack. Natural: Anti 1080/Department of Conservation protestors could carry out an attack on a significant toanga. How do we This is not a focus of CDEM. Police will have plans in place and the Emergency manage this risk? Operations Centre will be available for a response if required. What more • No further action recommended. should we be doing? What is the future • Recent history would suggest that NZ will become a target at some stage. risk? Water/Sewerage System Failure Overview MDC operates five sewerage systems in Blenheim, Picton, Havelock, Seddon and Spring Creek/Grovetown. The flow in the wastewater reticulation relies largely on gravity through a continuous progression of pipes. There is very little opportunity to interconnect branches in the network. A breakage or blockage in the system will therefore affect all pipes upstream. The Canterbury earthquakes showed that all types of spigot and socket jointed pipe can be dislocated during severe ground shaking. Pipes, wet wells and manholes are all susceptible to ‘floating’ in areas of liquefaction. Ground movement can also disturb the gradient required for gravity flow. Blenheim, Picton, Havelock, Renwick, Awatere (including Seddon), Wairau Valley and Riverlands all rely on public water supply with many other outlying communities being on local community supplies not operated by Council, for example Rarangi, Tirimoana and Momorangi Bay. Hazard Likelihood Electricity failure, loss of water supply, software failure, mechanical breakdown, (C) earthquake, heavy rain flooding and tsunami all have the ability to adversely affect sewerage infrastructure to different degrees. The likelihood of contamination of the water supply from an emergency is considered to be low although treatment is routinely required for many supplies. Extreme flooding or earthquakes can disrupt supplies either at source or through the reticulation network. Electricity supply failure has also been identified as a potential risk to water supplies. The 2017 Havelock North water contamination event has provided agencies with responsibility for drinking water treatment, with lessons that could be applied locally. Hazard Social: Consequence (3) • Failure can lead to human disease and death risk and disruption to business and social activities. Economic: • Physical damage to network infrastructure can take considerable time to repair leading to loss of productivity particularly from ‘wet’ processing industry that are unable to make trade waste discharges. Marlborough Civil Defence Emergency Management Plan, 2017-2022 Page 103