Nearly 1,000 deep-water wells in western Taiwan’s Changhua and Yunlin counties will be sealed over the next 10 years as part of ROC government plans to halt land subsidence threatening operations of the high speed rail.
Under the NT$52.8 billion (US$1.83 billion) program, 30 deep-water wells are to be capped by the end of the year, with 180,000 shallow-water wells left operational as they have been deemed to have no impact on the situation, according to the Public Construction Commission July 25.
The latest PCC figures indicate that 51.4 square kilometers of land in Changhua and 397.6 in Yunlin experienced annual subsidence rates of 5.3 centimeters and 6.8, respectively.
“The project will limit the subsidence rate to 3 centimeters per year in both counties,” PCC Minister Lee Hong-yuan said. “If properly executed, the plan is likely to guarantee the high speed rail’s long-term safety.”
Overpumping of groundwater in the area has seen sections of the high speed rail sink, forcing the government to halt three roads linking the planned Huwei Station in Yunlin to three adjacent towns. If subsidence continues, there is a real chance the railway will be forced to operate at reduced speeds.
Further PCC-initiated measures include closing another 416 deep-water wells after the Hushan reservoir comes on line toward the end of 2014. An additional 527 wells will be shut off by 2021, slashing groundwater usage by 490 million tons per year.
“Water-saving irrigation methods and increased recycling by industrial outfits will ensure the region’s supplies remain unaffected by the plan,” Lee said.
Write to Meg Chang at meg.chang@mail.gio.gov.tw