A local council in Sydney is enjoying the benefits of a dedicated asset management program, utilising the benefits CCTV inspection technology is able to deliver to its customers and the community.
The council began the process of cataloguing their stormwater assets in 2009, with a view to developing a comprehensive asset inventory which outlined the condition of every asset and allowed for the planning and execution of a maintenance program that was efficient and minimised risk and economic impact.
The pillars of the asset management program to be implemented by the council were as follows:
- Develop an accurate stormwater asset inventory and be able to report on each individual stormwater asset’s attributes, location and condition.
- Introduce a ranking system for stormwater asset defects to enable defect repairs to be prioritised.
- Introduce best practice trenchless technologies to economically extend life of assets.
- Reduce reactive maintenance expenditure resulting in lower overall annual maintenance expenditure.
- Develop and progressively update accurate Asset Management Plans which will provide a platform for continuous improvement.
- Develop a scalable asset management approach that could be adopted for other management programs.
Setting the scene
Council’s drainage assets include more than 500km of piped drainage systems and associated pits, gross pollutant traps, flood retention basins, formed channels and waterways with a combined value of over $350 million. The drainage network is projected to grow at a rate commensurate with the growth in the road network.
Prior to the implementation of this program the council had an outdated asset register with very limited information available for work planning and programming.
Council commenced a program to comprehensively inspect its piped drainage network to assess its structural condition and hydraulic performance. These inspections, which use a closed circuit television (CCTV) system, are ongoing and their purpose is to provide council with accurate condition data and digital imagery of its pipe network infrastructure.
The commencement of theses inspections has enabled council to proactively develop maintenance and renewal strategies that are responsive and cost effective. They have identified the need for the following broad categories of drainage renewal and replacement activities, which are expected to improve hydraulic performance and significantly extend service lives:
- Restoring the piped drainage system through the relining of long lengths of existing deteriorated pipes. This trenchless method of pipe restoration uses robotic techniques to apply a PVC liner within existing pipes to restore structural integrity and flow efficiency.
- Restoring the piped drainage system through the application of structural patches to isolated failures within pipes using the trenchless method.
Both these programs utilise technology that has been transferred from the water and sewer industries and this council is one of a few councils that has embarked on a large scale planned stormwater pipe renewal program using these trenchless and environmentally sympathetic technologies.
To enable works to be delivered efficiently, council has established long term contracts with ITS PipeTech who specialise in pipeline and culvert rehabilitation works for ongoing maintenance and renewal of stormwater drainage.
Council’s works programs are undertaken on a priority basis and funded by the Stormwater Management Service Charge.
Priority protocol and risk management
The priority selection protocol for risk management procedures, restoration, renewal and replacement of drainage systems is based on asset condition assessments and knowledge of other performance parameters including strategic location of pipes, flooding and community safety.
Benefits provided by the project
By identifying, targeting and repairing stormwater pipelines before they fail, council has been able to greatly minimise silt and debris entering the water courses during rain event as the result of collapsed pipe lines. Furthermore, the cleaning of the stormwater pipelines as part of CCTV inspection was carried out using combination units which remove silt and other debris (such as plastic bags and bottles) existing in lines, preventing the material from entering any waterways.
The resultant effect is the improvement of water quality, the overall ecosystem health and reductions in the occurrence of flooding and drainage control issues.
A best practice example
During the audit stage of this program council’s stormwater pipes were found to be in worse structural condition than first thought. Defects included missing pipe sections, large joint displacements, bends, and protruding connections mainly due to aged and poorer construction standards.
Lack of a progressive maintenance program would have led to these defects developing further, and can often make it difficult or impossible to rehabilitate the pipe without costly civil repairs or open cut relays.
This program implemented proactive replacement prior to complete collapse and saved council more than 50 per cent of the cost by using a trenchless solutions compared to traditional open excavation and replacement.
Following implementation of this program council is able to confidently:
- Manage workflow
- Manage budgets
- Reduce public complaints
- Demonstrate value to ratepayers
- Build up a knowledge base of assets
- Apply best practice protocols.
Further benefits will come to council within the next five to seven years, by which point council will have a 100 per cent accurate asset inventory and condition data.
With accurate data, staff will be able to provide cost effective infrastructure solutions; and benefit from the knowledge transfer from ITS PipeTech regarding the latest trenchless solutions for repair and maintenance of stormwater assets.
Total pipe network: 590,000m+
CCTV completed: 130,000m
Pipe rehabilitated: 99,000m+
Relining completed: 4,700m+
Structural repairs completed: 5,000m+