Kota Baru: No land subsidence have been reported in Kelantan in the past 15 years, said the Mineral and Geoscience Department (JMG).
“Based on the department’s monitoring from 2007 until 2022, there was no land subsidence recorded in Kelantan that can be associated with the use of groundwater,” it said in a statement yesterday in response to a story carried by The Star on Nov 10.
The department also denied that excessive groundwater extraction has caused some parts of Kelantan to subside.
“Hydrogeological modelling that has been carried out by JMG found that the safe yield for an underground water well field in Kelantan is at a rate of 406 million litres per day.
“The current groundwater pumping is at a rate of 198.2 million litres per day (48.2%), which is below the safe yield rate,” it said.
The department said the groundwater level recorded from 1989 until 2018 also did not show any significant or sudden drop.
“Hydrography data from Guillemard Bridge Station, Tanah Merah, from 1979 until 2018 also shows no significant decrease in river level.
“There is no underground water pumping for commercial or massive use recorded in Kuala Krai that can cause ground subsidence,” it said.
The department, which is the leading agency for governing underground water resources, also welcomes collaboration from various groups to monitor the country’s groundwater to ensure its sustainability and safety.
The Star reported that the use of groundwater as the main source of Kelantan’s potable water is threatening to cause more parts of the state to subside, with experts warning of more floods as a result.
Dr Yong Chien Zheng, formerly from Universiti Teknologi Malaysia’s Faculty of Built Environment and Surveying, said his 2018 study on ground movements in the state has found evidence that parts of the state were sinking by up to 4.22mm per year, with 17 years of GPS data in 11 different locations pinponting Kuala Krai as having the highest subsidence rate.
He said although insufficient data made it difficult to pinpoint the main cause, there was a high correlation between subsidence – the sinking of land or buildings to a lower level – and groundwater extraction.
