The native bass species will be able to migrate and breed in the Parramatta River for the first time in 200 years following the installation of three of a proposed four fishladders at the Marsden Weir fishway, writes Sarah Falson.
The Parramatta Weir Project was opened officially by the Parramatta Lord Mayor, Paul Garrard, of the Parramatta Council in November but begins operation this month. The system is designed to raise numbers of the native freshwater fish, which have been reduced due to regulation of rivers across New South Wales.
The weir works by using three hydraulically-operated gates that draw fish into a ‘fishlock’ by manipulating water velocities within the structure.
Once fish are trapped in the fishlock, the water within the area is adjusted so that it is equal to the headwater level. Fish are then free to leave the fishlock and continue their upstream migration.
The hydraulic gates then release the water so that it is equal to the tailwater level and is ready for attracting new fish into the fishlock.
Each hydraulic gate at the Marsden Weir fishway, located upstream of Parramatta Wharf, is controlled by a programmable logic controller (PLC) which uses gate positioning and water level sensors as process control inputs. The PLC using these process inputs initiates each sequential phase as programmed.
Parramatta-based CIS Complete Industry Solutions was responsible for commissioning the control components for the Parramatta Weir Project. According to CIS Director, David McCaughey, the company — together with Moorebank-based Moblack Hydraulics — developed a new cabinet to house the gate hydraulics system.
CIS is an engineering solutions company specialising in pumps and meters, hydraulic systems, PLCs, control systems, repair and maintenance, and calibration.
“Between ourselves and Moblack we came up with the SCA Cabinet design, which accommodates the Hydraulics, and uses separation compartments for the high and low voltage equipment,” McCaughey old PACE.
“Norselec Switchboards at Kurnell built the stainless box and wired in the components to our supplied drawings. This was not a standard cabinet as it was only 1.1 metres deep, 1 metre wide and 2.4 metres long; the reason for this was that the cabinet was going underneath the Riverside Theatre at Parramatta.”
According to McCaughey, the civil engineers working on the project encountered problems with seeping water throughout their excavation work, “We also found this to be a hurdle whilst carrying out the hydraulics and electronics,” he said.
“As the civil engineers were progressing, the programming of the touchscreen and the PLC were taking place. These were then handed over to Norselec to fit into the cabinet and wire. Once the concrete was finished we then moved down to site: the box was installed under the theatre, and the power pack and accumulators were fitted.”
Running to the Weir from the cabinet are six hydraulic lines, three water sensor multi-core cables and three gate sensor multi core cables. Balluff-Leuze Micropulse Linear Sensors were fitted inside the hydraulic rams and are used for gate positioning.
Water level sensors are fitted into stilling tubes inside the Weir and in the headwater channel. STE moisture proof termination enclosures were also fitted inside the cabinet for the termination point for the sensors. These cables were 150 metres unbroken from the Weir to the cabinet, according to McCaughey.
“The gates were fitted and commissioning began,” McCaughey said. “The unit has now been running for a couple of months with out problem: there are claims that fish have already been seen.”
Other equipment used in the project include a 10-inch Red Lion touchscreen; Omron CJ1M PLC multiple input and output modules, analogue module and communications module; Omron GSM Modem used for alarm messaging and dial-in remote diagnostics; Puls DC UPS System and battery; a surge diverter; and a phase failure relay.