The city of Bunbury in Western Australia is upgrading the Five Mile Brook pump station. The collaborative approach between client, contractor and pump supplier highlighted the benefits that can be achieved when all parties work closely together.
The City of Bunbury owns and operates a stormwater pump station at the termination point of Five Mile Brook (FMB) in Bunbury. Late last year the City of Bunbury determined the FMB pump station to be inadequately performing and in need of an upgrade.
The FMB open stormwater channel services an extensive area. At the discharge point, the existing arrangement allows stormwater to either drain via gravity or be conveyed by the pump station into the ocean. he City of Bunbury owns and operates a stormwater pump station at the termination point of Five Mile Brook (FMB) in Bunbury. Late last year the City of Bunbury determined the FMB pump station to be inadequately performing and in need of an upgrade.
The system failed to discharge a sufficient volume of stormwater during severe weather events, particularly during extreme high tide when the gravity flow system was prevented from functioning. Additionally, during heavy rain the pump lacked the capacity to remove the required volume of water from the channel, resulting in potential widespread flooding.
The FMB pump station has been identified as a critical asset, with the upgrade to greatly reduce chances of it failing. This capability will enable the upgraded pump station to mitigate flood risks for future generations
The scope of works to be completed included:
- Concept design
- Detailed design
- Construction of the pump station, discharge pipe, electrical and control building, and all associated elements
- Commissioning and testing of the pump station.
The tender documentation specified that the upgraded stormwater pump station would include a stormwater discharge capability of 1,000 litres per second; a 400 per cent increase on current capacity.
During normal operation the discharge from the pump station (comprising two identical pumps) will scour the ocean side of the outlet to facilitate a gravity flow function from the FMB pump station to the ocean.
As a primary performance outcome during storm events, and when tides prevent normal operations, each singular pump needed to have the capacity to evacuate stormwater from the FMB pump station.
The FMB open stormwater channel, which terminates at the corner of Ocean Drive and Haywood Street, Bunbury, has an extensive catchment, extending to the areas surrounding Dalyellup and Gelorup within the Shire of Capel.
The design and construction had to consider aspects including public safety, operator safety, cost effectiveness, value for money, operational reliability, operational flexibility and monitoring via SCADA, maintenance requirements, including access, durability and reduced operational input, contingency operating modes, including the provision to hire pump sets or a generator, and security of the facility.
Working in partnership
Following the competitive tender process, the City of Bunbury awarded the FMB pump station upgrade contract to Ertech. Both parties took a collaborative approach to the project, establishing a unique working relationship which delivered real benefits to all parties.
Dion Todd, Project Manager at Ertech, outlined some of the particulars of the project.
“The City of Bunbury specified that the pumps selected for the upgrade project be from Xylem, as their existing pump system was a Xylem one.
“Ertech, along with hydraulic engineering consultant Hyder, worked closely with Xylem to develop the right pumps for the system upgrade. Because we were working in a brownfield environment, we were after pumps with unique specifications and modifications.
“We developed a close working relationship with Hyder and worked together as a team to decide upon and develop the best pump for the job.”
According to Mr Todd, factors under consideration in the design process included regular performance versus one in 100-year event requirements, and the available power and size of the site.
The team also worked closely with Xylem to specify the right pump for the job.
“Xylem proposed a Flygt pump, and with the right modifications, it proved to be the right pump for the job,” said Mr Todd.
“Given that we were after quite a specific product for the job, the pumps have had quite a long lead time. The pumps have been ordered from Xylem and are being shipped here.
“The pump selection was really the central factor in terms of specification for this project. Once we had the pump locked in, we were able to proceed with many of the other important elements of the project.
“Given the environment we were in, this was a very interesting and challenging project. The Five Mile Brook pumping station upgrade was a unique project, requiring a unique solution, which we believe we are on track to deliver,” concluded Mr Todd.
Works began on the FMB pump station upgrade in February 2015, and is due for completion in the first half of 2015.