The Ministry of land, transport, and maritime affairs announced details of an 18-billion-dollar waterways project aimed at reducing flooding and drought, as well as creating tens of thousands of jobs.

The plan to improve the country's four major rivers will cost 22.2 trillion won (17.8 billion dollars) by 2012, said the ministry of land, transport and maritime affairs.

It is a major plank of the government's "Green New Deal" to create jobs and lay the ground for further economic growth.

Work will begin before the end of this year to build dams, banks and water treatment facilities, the ministry said.

The plan calls for 16.9 trillion won to dredge rivers, to develop parks and recreation facilities on banks, and to build dams, catchment basins and reservoirs capable of storing up to 1.3 billion cubic meters (84.5 billion cubic feet) of fresh water.

A further 5.3 trillion won will be used to improve water flow and to build 750 sewage processing plants and 46 new water treatment facilities.

The ministry said that without such action the country would suffer a water shortage of about one billion cubic meters a year by 2016 because of climate change.

River banks will be strengthened and floodgates will be built on the estuaries of the Nakdong and Yeongsan rivers. Flood damage and efforts to prevent it cost the country about eight trillion won every year, the ministry said.

Environmentalists have raised concerns over water contamination and disruption of the ecosystem. They want careful environmental impact assessments before any work goes ahead.

Some economists also question the government's assertion that the plan will create 190,000 jobs.