Curtailing evaporation in major storages

The National Program for Sustainable Irrigation has had an active interest in evaporation as a researchable issue for more than 10 years, looking at the big picture as well as farm-based practices to reduce evaporative loss.

It was a sponsor of an international workshop at the Gold Coast in 2009, for example, to address priorities and foster the exchange of knowledge.

Today, along with its own funding partners (listed at the conclusion of this newsletter) NPSI is a proud contributor to ground-breaking collaborative research involving the CRC for Polymers. Led by University of Melbourne scientist Professor David Solomon, a project titled New Technologies to Reduce Evaporation from Large Water Storages has produced promising new benign chemicals to provide a barrier to the loss of water through evaporation. It is now entering a demonstration phase.

Laboratory performance substantially exceeds that of commercially available products of this type, according to the CRC for Polymers, which adds that a feature is that a thin surface layer forms in such a way as to restrict transfer of water to the air while still allowing oxygen transfer. Demonstration sites are now evaluating performance and refining the necessary components of management to be successful, including controlled application and maintenance.

While the focus is large scale storage (e.g. reservoirs) where evaporative losses can exceed 40% of water stored, it is hoped that delivery infrastructures and on-farm storages will also benefit from this research.

Advanced film technology will be introduced to applied research undertaken at field sites where the Cotton CRC, CRC for Polymers and the University of Southern Queensland have an interest.

The man on the ground at one of the sites, a cotton property owned by Rob Jakins at St George, Qld, is irrigation consultant Justin Schultz.

“Two dams at the site, each about 1000 megalitres capacity and with a 12 hectare surface area, allow a ‘standard’ storage to be compared with treatments,” he said.

“Applicators for the polymer film have yet to be installed but baseline data on seepage and other factors has been collected.”

Justin says the industry is looking forward to results from the project because while some growers have tried existing products and cut evaporation by 20% or more, the quest is for greater gains from using polymers – whether this be from higher levels of evaporation reduction or lower application costs or a combination of both.

“It is certainly worthwhile research considering the fact that evaporation is the biggest on-farm loss in parts of Queensland where storage on the property is the only option,” he said.

“The water can be carried for months before use, losing 50% or more to evaporation and where property owners store for longer, for two crops, the loss is even worse.

“Reducing evaporation is an obvious way of pushing our water further and improving productivity.”

Citation

Land & Water Australia. 2011. Curtailing evaporation in major storages. [Online] (Updated February 25th, 2011)
Available at: http://lwa.gov.au/node/3809 [Accessed Wednesday 29th of February 2012 08:31:35 PM ].