An Australian manufacturer of plastic outdoor shade cloths wants to cover the nation's dams to save water.
But it says the viability of covering large expanses of water to cut evaporation as Australia battles against a crippling drought will depend on the future price and availability of water.
Melbourne, Australia-based Gale Pacific Ltd. has supplied high density polyethylene shade cloths for a two-year research project into water storage conducted by the Australian government's major research and development body, the Commonwealth Scientific & Industrial Research Organization.
Paul Cacioli, Gale Pacific's general manager for research and development, said CSIRO and water authorities in the state of Victoria had wanted to see whether shading dams could reduce or eliminate algal blooms that contaminated water supplies.
“While the main reason for the research was to reduce algal blooms and other floral growths, they also recorded falls in evaporation rates of about 90 percent,” Cacioli said.
Experiments were conducted between 2004 and 2006 at four small dams in regional Victoria using Gale Pacific shade cloth.
Cacioli said the CSIRO project had used Gale Pacific's Commercial 95 shade cloth that cut sunlight penetration by 95 percent.
The shade cloth is manufactured in rolls 9 feet 10 inches wide and 164 feet long at its plant in Ningbo, China.
Gale Pacific fashions the cloth into a range of shade products for domestic and commercial uses. The products sell in Australia and Gale Pacific has export markets in the U.S., Europe, the Middle East, and New Zealand.
Cacioli said it currently did not appear feasible to apply shade cloth to all dams, despite critical water shortages in many parts of Australia because of the ongoing drought.
“You have to build supports for the shade cloth, and some people say it is not cost effective,” he said.
“But that could change, depending on the price put on water and whether it becomes less and less available.”
CSIRO said results of the research project are in the final stages of analysis. In addition to the huge reduction in evaporation rates, the shade cloths seemed to limit significant algal blooms in covered dams during summer months.
Bacterial contamination has fallen and the covers keep out water birds and wind-borne debris — all of which reduce maintenance costs.
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