Risk Assessment for Integrated Water Systems

Previous Next

Integrated water management systems are essential components of urban infrastructure, offering space-saving benefits and ease of installation. While their importance is particularly pronounced in seismic zones, where maintaining structural integrity is crucial, it is also vital to consider the broader implications of ground movement. This includes ground subsidence, expansion, and contraction, which can cause even minor shifts in the earth to impact the foundation and integrity of water storage solutions.
 
Take Auckland for example, where seismic activity is low, but the soil is predominantly clay—a highly expansive soil type—the risk of ground movement is exacerbated by the soil's tendency to expand when wet and shrink upon drying. This constant fluctuation poses a significant challenge to the resilience of integrated water systems, necessitating a comprehensive approach to risk assessment that accounts for all forms of ground movement.
 
This article aims to explore the potential risks and maintenance responsibilities associated with integrated water systems in the context of both seismic activity and ground movement. By examining the implications of system failures and the importance of robust design and regular monitoring, we will provide industry professionals with valuable insights into ensuring the reliability and safety of water storage solutions in the face of natural forces.

 
Risk Analysis

The resilience of integrated water management systems, particularly in seismic zones, is a critical concern for urban infrastructure. While modular designs offer flexibility and scalability, they also introduce multiple potential points of failure that can be exacerbated by ground movement. This risk analysis will consider not only the seismic activity but also the effects of ground subsidence, expansion, and contraction on water storage systems.

• Leak Potential in Modular Water Storage Systems

Modular water storage solutions, with their interconnected components, are susceptible to leaks at each joint or connection. In seismic zones or areas with highly expansive soils like Auckland's clays, the risk of ground movement— caused by soil expansion when wet and shrinkage upon drying—can lead to structural shifts, increasing the potential for leaks.

• Consequences of System Leaks in Seismic Zones

Leaks within structural slabs can result in significant damage, such as structural compromise and mould proliferation. Ground movement can magnify these issues, leading to extensive repairs and safety concerns, even in the absence of an earthquake.
 

Compliance:

Products and components used in construction need to meet specific durability requirements Under B2 of the New Zealand building code, as outlined in the table below:

Rotomolding resins are formulated to meet AS/NZS 4766:2-02- which stipulates a 20-year design life. This means that rotationally molded products and components can only be used in situations up to ‘moderately difficult to replace’ scenarios and is the reason why we cannot endorse installing tanks underneath a building, because under B2 of the building code, they cannot meet the durability requirement.
 
However, driveways are considered moderately easy to replace, which is why our tanks are suitable to be installed under driveways.
 
This is not saying that tanks will not last beyond 20 years, we have got plenty of tanks which have well outperformed this, but only because the material has not been tested to this level. 
 
 

Responsibility and Liability

In New Zealand, property owners typically bear the responsibility for plumbing leaks. However, if leaks result from product faults or improper installation, liability may extend to manufacturers or installers. It is crucial to consider the broader implications of ground movement in determining responsibility and liability.

Mitigation Strategies

To ensure the longevity and safety of water storage systems, comprehensive mitigation strategies must be adopted. These strategies should include best practices and monitoring techniques designed to minimise risks and enhance system resilience against both seismic activity and ground movement.
 

• Installation Best Practices

Employing experienced professionals and adhering to strict installation guidelines can minimise the risk of leaks. Regular inspections during construction can ensure that all connections are secure and can accommodate ground movement
 

• Post-Installation Monitoring

Incorporating leak detection systems and regular maintenance checks can help identify and address leaks early, before they cause significant damage. Monitoring soil moisture levels can also be a crucial step in preventing ground movement-related issues.

Repair Solutions

Effective repair solutions must be in place to address the challenges posed by seismic activity and ground movement on water storage systems. Spot repairs and re-piping may be necessary, and specialised repair methods that account for ground movement should be employed.
 

• Spot Repairs: For isolated leaks, spot repairs involving opening the slab at the leak point and repairing the leaking pipe may be sufficient.
• Re-Piping: In cases of multiple leaks or systemic failure, re-piping or complete replacement of the affected lines might be necessary.
• Seismic Considerations: Specialised repair methods that account for seismic activity should be employed. Flexibility in piping and reinforced connections can provide additional resilience.

Conclusion

When considering water management systems for use in seismic zones, it is essential to balance the innovative features of these technologies with the potential risks they may pose. Engineers and architects must thoroughly evaluate the benefits and vulnerabilities of such systems and implement robust measures to mitigate any identified risks. This ensures the safety and effectiveness of water management solutions in regions where ground movement is a significant factor.

For further guidance and expert consultation on water management systems in seismic zones, contact our team today. Let us help you ensure your project meets the highest standards of safety and resilience. Reach out now to schedule a consultation and take the first step towards a more secure infrastructure.

---

This article serves as a general guide. For specific projects, a detailed analysis and consultation with local experts are recommended to address the unique challenges of the site and regulatory environment. Please note that this document is based on information available up to 2021 and should be verified with current local standards and practices.

Request a Consultation