Our engineers assess new share sales to determine how best to modify the scheme to supply additional water. Hydraulic models are maintained to allow performance monitoring of the scheme and to determine where spare capacity is available.
Scheme performance is monitored across the scheme constantly. Any potential or actual performance issues are assessed by our engineers and then appropriate solutions are implemented by working closely with our maintenance team.
Scheme reliability is critical. Our engineers monitor the scheme assets to ensure that reliable water supply is maintained to our shareholders. Unplanned events such as power outages, floods and pressure fluctuations are monitored, and the engineers work with the operations and maintenance team to restore supply as quickly as possible. Planned maintenance outages are occasionally required to ensure the longer term reliability of the scheme is maintained.
The engineering manager works closely with the operations manager and the maintenance team to determine the short term and long term asset management requirements across the scheme. This includes identifying critical spare parts, working with suppliers to identify and source spare parts and consumables, and determining the long term asset replacement requirements of the scheme to inform the capital budget planning process.
A key part of our asset maintenance programme is preventative maintenance. The engineering manager works closely with the maintenance engineers to define and schedule all preventative maintenance on the scheme assets. Where possible maintenance is deferred to outside the irrigation season, but in-season routine maintenance occurs throughout the year to ensure the scheme assets can continue to supply water.
Protecting our Pipelines
Planning to dig?
If you are planning to excavate within the scheme area please ensure you lodge a request with beforeUdig.co.nz to avoid damaging our scheme assets.
The CPWL scheme contains many hundreds of kilometres of buried pressurised water pipes ranging in diameter from 2.5 metres down to 150mm. We also have many electricity and communications services buried throughout the scheme area.
If you are planning to excavate and are unsure if it will impact our scheme then please contact our Maintenance team.
Material and component quality have been a primary focus from design through to operation. Quality products and components were selected during the design and construction phase and reputable local and international suppliers were used on all scheme componentry.
All scheme pipelines have an 80-year design life. The GRP pipeline has been internationally sourced to appropriate AS/NZ standards; designed to AS/NZS2566.1, manufactured to AS3571.2 and ASTMD3517 and installed to AS/NZS2566.2. The GRP pipe supplier was selected after a rigorous international search. These standards typically apply to municipal schemes in New Zealand.
The HDPE pipeline materials are traceable back to the raw materials (HDPE beads) used in the manufacturing process. The pipes were manufactured on-site and installed in 100m lengths to reduce the number of pipe joints in the scheme. HDPE pipe was designed to AS/NZS2566.1, manufactured to AS/NZS 4130 and AS/NZS2033 and installed to AS/NZS2566.2.
The headrace canal is fully lined with HDPE liner and has an 80 year design life.
Key assets have been designed to withstand a 1:500 year seismic event and river intake assets have been designed to withstand 1:100 year flood events.
By utilising stored water, the scheme has the reliability to enable shareholders to maintain reliable water supply up to a 1:10 year drought.
Construction was procured through a rigorous selection process to ensure only internationally qualified Contractors were engaged.