Effective law enforcement and proper technology are urgently needed to stop further land subsidence in Bangkok and near by a province which has been continuing due to excessive commercial use of groundwater, experts have warned. Otherwise, they said, cities will be more vulnerable to floods and seawater contamination, while land areas could subside to levels as low as in the Netherlands. Kriengsak Srisuk, director of the Groundwater Research Centre at the Department of Groundwater Resources, said around 20% of land in Bangkok had already sunk by almost a meter during the past 30 years due to excess pumping of groundwater for use by industry. If the trend continues, Bangkok may sink into the sea in 50 years and need dykes built to project against seawater flooding, he said. Speaking at a publish hearing on a master plan for groundwater management and development, Mr. Kriengsak said the law limiting groundwater pumping needed to be amended since it had not been effectively applied. Bangkok will likely see worse flooding as well as seawater contamination in its underground and above-ground water resources, he said. He said the master plan would include measures to take the problem by implementing a pilot project in demonstration areas using technology from western countries to help restore groundwater levels. The department of Groundwater resources is preparing the so-called master plan to implement integrated strategies and practices for long-term groundwater management to suit economic and social conditions over the next 20 years. Albert Tuinhof, a groundwater management expert from the World Bank, said new technologies can be applied to stop land subsidence in Bangkok and its adjacent areas. “It should go hand-in hand with regulations, otherwise (it means that) you invest in stopping the land subsidence but at the same time well drillings are continued. The land then will continue to subside,” he said. As the adviser to the master plan, Mr.Tuinhof said this technology would be costly for Thailand but the country would have to pay a heftier price in terms of the economic impact if it chose not to deal with the land subsidence problem. Bangkok can also learn from the experiences of cities such as San Francisco where groundwater pumping has continued since the 1960s resulting in land subsidence of 10-15 meters, he said Since Thailand has a lot of groundwater available, the master plan will provide a framework for effective consumption as well as guidelines for groundwater users to drill the right well in the right locations, said Mr. Tuinhof “It will help to protect from major impacts on and large costs to communities and the economy,” he said. Sucharit Koontanakulvong, an expert from Chulalongkorn University’s Faculty of Engineering, said land subsidence in inner Bangkok had lately fallen to 2-3 cm a year due to tap water supplies replacing the use of groundwater.