Southern Highlands Irrigation System
As part of the Southern Highlands Irrigation Scheme Netco Pumps was asked to install the pumping stations and pipework manifolds at the 3 pump station sites. The Shannon River was the site of the main extraction pump station and this station had the complexity of needing to perform several different duties within the pump configuration. The pump station was to be able to pump a total of 85ML/day of raw water to a 6000 ML storage dam on one side and a header tank which would feed the irrigation pipeline on the other. In the summer season, it would also boost water from the dam to the header tank and as a fourth mode, it needed to be able to catch summer flows and pump both to the dam and the header tank simultaneously.
The resultant design was for a total of 10 split case pumps with vertical mount motors and these were configured in two banks of 5 pumps. The first bank was the suction pumps which operated at a fixed speed and pumped into a common manifold feeding the second bank of pumps which operated with variable speed motors. In the boost mode, only the second tier of pumps would operate and the speed and number of pumps running were carefully analysed with the performance curves and varying operating heads to get the most efficient operating points possible. This involved a lot of work with the electrical design engineers but the result was a very flexible and efficient pumping system as well as an impressive array of pumps, large manifolds and automatic valves.