Tight specifications are a challenge for emergency irrigation
A recent request from a rural client to design and install a pump system that could provide emergency irrigation for a dryland farming and cropping research facility tested the design and installation skills of Tony Giddings from Gosford Irrigation and Water Solutions.
The property, located near Boorowa in south-west New South Wales, has frontage to a local creek, which was used as the water source for the emergency irrigation system, which was designed to be operated only for drought protection.
TIGHT SPECIFICATIONS
According to Tony, there were several challenges that had to be overcome when designing the pump sets to ensure they would operate efficiently and effectively.
“The first challenge was that the creek that was used to supply emergency irrigation water to the farm also supplies Boorowa with town water, and it was essential that any extractions did not affect this supply,” he said. “This was monitored five kilometres from the farm and was based on a specific measured flow over Boorowa weir, which meant that we couldn’t access water when the flow went below this level.”
To ensure flow did not go under the level specified, a secondary check is also completed by farm staff at a creek crossing 30 km from the farm.
The next, and probably biggest, challenge was developing a design for the pump stations that would deliver irrigation water to several different cropping areas that were in different directions from each other. At the same time, it was essential to ensure they all communicated and worked with each other and that they conformed to the job as specified.
With these constraints, it was decided that the hub of the system would be a 60 ML holding dam, which could be filled when water levels as monitored at the weir allowed. Water level data is transmitted through GSM every six hours, and this is confirmed by a manual check at the creek crossing.
When all systems are “go”, the holding dam can be filled using a trailer-mounted Goulds ISO 150x125-315 37 kW 4-pole pump. Being trailer mounted, the pump can quickly be relocated away from the creek bank where it is normally sited if there is heavy rain or flooding is likely. If the water level in the creek is rising, the farm managers are notified via software connected to the central monitoring system.
A second pump station on the holding dam is used to fill two other smaller dams as well as irrigate some crops.
This pump is a Lowara triplex booster system e-SV vertical multistage pump set using two 66SVs and a 33SV, all LNPSH pumps.
The pump sets on the two smaller dams are a single Lowara 33SV 425 V pump set and a single Lowara 10SV pump set.
All panels are INCA Control, and the primary pump station can be monitored remotely using a mobile phone, with interconnections to the other pump stations.
DAM AND TANKS ARE FULL
John Veasey from Brown Brothers Engineers Sydney branch, who supplied the pumps, control panels and weir level monitoring devices explained that aspects of the system were modified to fit the application during construction and commissioning with Tony while they were on-site.
“Fortunately, we were able to offer flexibility around product selection and had a number of alternatives to work with ensuring he had the right solution,” he said. The new system was commissioned in February-March this year and has been doing its job, as planned, by operating efficiently and keeping the dam and tanks full.
[Article originally appeared in the Irrigation Australia Journal]