Case
Grundfos delivers dependable water for Whakatane District Council
Whakatane is the regional centre for New Zealand’s Eastern Bay of Plenty, supporting a district hospital, schools, homes and a busy tourism sector. Water is drawn from the local river, treated, and pumped up to three reservoirs on the hill adjacent to the plant which then feeds the township and Ōhope Beach suburb nearby. The high-lift pumps for this process are critical infrastructure.
With the existing pumps becoming aged and inefficient, Whakatane District Council selected their local Grundfos agent and worldleading Grundfos technology to deliver the town’s ongoing water security.
Normal daily demand at the plant requires the raising of 5,000 to 6,000 cubic metres of water per day. In the summer tourist season, this daily figure can rise to 12,000 m³ per day. Similarly, the Bridger Glade station on-supplies approximately 30% of the plant production per day.
The town’s old high-lift pumping system comprised three 160kW single-speed pumps, with motors that had all been in service since installation in the mid-1980s. The Bridger Glade station, being of a similar age, housed two single stage 160 kW pumps. These on/off pumps offered low energy efficiency and were noisy to run. Their age was also impacting on service and parts support.
In the event of a serious pump failure, it was estimated the hilltop tanks could provide just 12 hours of water before the hospital and other civic amenities became untenable.
To mitigate this risk, Whakatane District Council decided to replace the ageing pumps with more modern system that provided greater capacity, flexibility, efficiency and redundancy.
Council engineers had established a strong relationship with the local Grundfos agent, Opotiki Pumps and Irrigation, through several other projects. Valuing the world-class quality of Grundfos pumps and the responsiveness and expertise of the local partner, Opotiki Pumps was appointed to the Whakatane pump renewal projects.
“Having a very responsive local partner with Grundfos backing gives us a lot of confidence – from the efficiency of the design process to the recommended products being right for our needs.”
THE SOLUTION
Opotiki Pumps designed modern Grundfos high-lift pumpinginstallations. For the plant, this was based around a Grundfos Hydro MPC-EF-CR155-3-3 system with five 55kW pumps, each rated at 186m³/hour flow and 83.4m head. The Bridger Glade station, was set up for duty/standby operation with two Grundfos CR155-2-1, 45 kW pumps, each again capable of 186m³/hour.
These pumps are operated via new Grundfos CU352 Advanced multi-pump control panels with external Grundfos CUE variable speed drives, remote SCADA telemetry, multiple system alarms and advanced pump cascade control.
At both stations, the newer technology delivers more water while using less power, with variable output making the pumps even moreefficient to operate as water usage fluctuates.
Opotiki Pumps provided an end-to-end service, including solution design and stainless steel piping, pump connections, control panel installation and system activation for both of these station upgrades.
As ‘live’ activations were required, each of the new pumps was sterilised and brought online while the water transfer stations continued working.
THE OUTCOME
Whakatane District Council now has modern systems to manage the town’s water needs for many decades. Engineering Services Manager Jim Finlay says power savings alone will see the new pumps pay forthemselves within a few years.
“The new pumps are quieter and more flexible,” he adds. “As a backup for the reservoirs, we can pump water directly into the mains. However, we need to reduce pumping pressure to do this safely, so having variable pumps enables another layer of system redundancy.”
As a result, the Council has all but eliminated vulnerability from their town water supply.
Over the past five years, Whakatane District Council collaborated with Grundfos to upgrade and expand eight water pumping facilities. These projects involved the installation of 25 new Grundfos pumps, along with associated control and hardware systems. The Council has witnessed notable reductions in operating costs across all facilities, typically ranging from 14% to 19%.
Additionally, the Council's electrical and mechanical service providers received training from Grundfos personnel for commissioning and maintenance, underscoring their satisfaction with the products' reliability, high-quality hardware, ease of operation, and simplicity of servicing.