​Interconnectedness and Interdependencies

Once Local Governments have determined the criticality of their assets, the next step in providing critical infrastructure resilience is to consider infrastructure interdependencies.
   
The critical infrastructure that underpins everyday life in localities across NSW is complex. It is heavily connected and is essentially a system of interacting, interrelated and interdependent components that form a complex and unified whole.
 
All critical infrastructure relies to some extent on other critical infrastructure for continued service provision.  As an example; water and wastewater infrastructure relies on energy, transport, and telecommunications infrastructure for continued operations.  Interdependencies can look like deficiencies in system design but during normal operations they provide efficiency and enhanced operational capability. Interdependencies mean that the consequences of critical infrastructure failure can be amplified and wide reaching. There is the potential for cascading failures; essentially creating a ‘ripple effect’ which can affect many parts of the community, not just the infrastructure providers themselves. As an example; an electrical substation might be flooded, which knocks out a water treatment plant, which in turn disables all the food businesses in the local government area. Local Governments need to understand these interdependencies to assist them to provide and support response and recovery services.
 
The sample interdependency model below (refer Figure 6) is based on electricity supply and illustrates the complexities involved delivering essential services.
Figure 6: Example of infrastructure system interdependencies

Interdependencies are complex and initial exercises may involve mapping basic linkages or dependencies that can be built upon over time. Achieving critical infrastructure resilience requires investing time and effort to identify and maintain data on these linkages. Working collaboratively with infrastructure providers through the LEMC will result in better planning and consideration of local critical infrastructure issues.  Regional critical infrastructure issues which are beyond the capacity of the LEMC to resolve, should be escalated to the REMC for action.

Using Geographic Information Systems for Decision Making

Having good data enables good preparation and good decision making.  Access to powerful map based tools via Geographical Information Systems (GIS) allows local governments to record asset data and build critical infrastructure resilience.
 
The value of GIS has been proven for asset management functions such as record-keeping via asset registers and effective preventative maintenance. The value can be extended before and during emergency events. Hazard data, such as flood mapping, can be overlaid on critical infrastructure to determine exposure e.g. what critical infrastructure will likely be affected by a 1% Annual Exceedance Probability (AEP) flood event or to overlay asset types e.g. is there a low criticality road leading to a vital criticality water pump asset that might impeded access after disaster impact.
 
Additionally, map-based tools facilitate information sharing between those who own and manage critical infrastructure systems and assets and those that may need to respond after a hazard event to assist in the restoration of services from infrastructure. Not all information needs to be open, nor shared, constantly. However, robust processes need to be in place to share relevant information in a timely manner as the need arises.  

Damage Assessments

Comprehensive, timely and accurate assessments of impacts to critical infrastructure with consequential implications for business continuity and continuity of government, will be of vital concern following a major event, and will have great bearing upon the speed and efficiency of response and recovery efforts.
 
Following any emergency or disruption to critical infrastructure that is owned or operated by Local Government, there will be a need to undertake a rapid damage assessment process followed by more comprehensive assessments at a later date. A robust and standardised process should be implemented to ensure that a complete picture of the situation is available. Good decision making requires accurate and comprehensive information, the flow of which will improve over time.