An innovative ecological project to clean up a polluted stream in Anne Valley in Co Waterford by constructing wetlands has proven to be a major success.
A total of 13 wetlands have been built throughout the 25 sq km Anne valley, south-west of Waterford city since 1996. It is part of a project to restore the Anne stream near Dunhill which had been seriously polluted by farmyard and sewage waste.
The wetlands, which treat dairy washings and farmyard effluent, have all been constructed by farmers on their own land. A wetland has also been created to treat sewage from Dunhill village.
One of those who has embraced the system is 36-year-old dairy and beef farmer Mr Eugene Dunphy.
He told The Irish Times the wetland "has solved what is a perpetual problem for farmers - great volumes of farmyard waste occurring at the worst time for landspreading, when it's raining".
"Before, we had a drain and at the end of every winter there would be a bit of mulch in it. It wasn't humanly possible to contain the dirty water without the wetland," he explained.
Mr Dunphy's five-acre wetland system is one of the biggest in the valley.
The benefit to the environment of the Anne Valley has been significant. Water quality in the Anne stream has improved and the variety of habitats along its length has increased.
Dr Rory Harrington, of the National Parks and Wildlife Service, who has spearheaded the project, said the wetlands slow the speed at which polluted water flows into streams and rivers. Water quality is also improved, he said.
He added: "Wetlands can contribute very significantly in meeting the requirements of the Nitrates and Water Framework Directives because of their capacity to remove nitrate and to provide overall cleansing including the removal of phosphorous.
"It's a soft engineering approach rather than a hard engineering approach associated with high energy and capital costs."
Each of the wetlands in the Anne Valley consist of approximately four irregularly shaped and different sized ponds, depending on the farmyard area feeding the system. Ideally the wetlands must be between 1½ and twice the size of the farmyard area that is feeding into them.
More wetlands are planned for the valley, supported by Waterford Country Council and Dunhill, Fenor, Boatstrand and Annestown Community Enterprise Ltd. "We use the land for growing crops, so why can't we use it for cleaning water?" asked Dr Harrington.