High cost of losing our wetlands

Economics

University of Adelaide research has, for the first time in Australia, put a commercial value on wetlands and shown the high economic cost of their loss to the nation.

PhD graduate Dr Carmel Schmidt examined the economic value of wetlands as natural filters of our domestic water.

"Wetlands are often referred to as the 'kidneys' of our river systems because of the important job they do purifying water by trapping sediments and removing impurities," Dr Schmidt said.

"But the impact on water quality due to the loss of wetland areas is little recognised. With the ongoing drought and increased risk to our wetlands because of the high demand for water for agriculture and other uses, this has become even more important."

It is estimated that over half of Australia's wetlands have been destroyed since European settlement.

"The Lower Murray dairy swamps were once part of a series of fresh-water wetlands stretching from Mannum, along the Murray to the Coorong, but of the original 5700 hectares of wetlands only 500 hectares remain today," Dr Schmidt said.

"This destruction of the wetland area is typical of wetland losses that have occurred across the country."

Dr Schmidt's research found the value of permanent natural wetlands for water filtration was at least $7100 per hectare per year and the value of constructed wetlands ranged from $14,100 to $28,000 per hectare per year.

"It would have been very profitable to include wetlands as part of the domestic water filtration process in South Australia instead of constructing water filtration plants," Dr Schmidt said.

Ten filtration plants were built in 1998 to service Adelaide and rural areas.

Previous studies on wetland valuation used a "willingness to pay" approach and put values between $82 and $300 per hectare per year.

Dr Schmidt completed her PhD within the University's School of Economics under the supervision of Head of School Professor Christopher Findlay.

Story by Robyn Mills