Posted on January 30, 2018
By Chen Wei-han, Taipei Times
Premier William Lai yesterday promised to ensure stable water supply for all sectors of the economy and encouraged businesses to invest in Taiwan as he presided over a ceremony to mark the completion of a major dredging system for the Zengwen Reservoir.
The holding capacity of the reservoir, which spans Chiayi County and Tainan, has been dramatically reduced in recent years by about 100 million cubic meters, or about one-sixth of its capacity, due to a build-up of sludge and sediment.
Typhoon Morakot in 2009 alone contributed 90 million cubic meters of mud, which prompted the government to design a dredging system to remove the sludge from the nation’s largest reservoir.
Construction of the NT$4.1 billion (US$141 million at the current exchange rate) system began in March 2013.
A 1.26km underground tunnel system was built across the hill on the left bank of the dam to the downstream Zengwen River to transport bottom sediment from of the reservoir to downstream areas.
The nation’s largest water resource construction project in years, it is considered an engineering feat, as it was carried out without a cofferdam enclosure.
The use of an “elephant trunk pipe” used to excavate bottom sediment is an unprecedented engineering design, Lai said during the ceremony.
“The priority of the government is to develop the economy and improve Taiwan. To enable a stable supply of water, the government has put forward methods, including creating additional water supply, water conservation, and transporting water across regions” to aid areas prone to water scarcity, the premier said in his speech.
Dredging has also been carried out at the Nanhua Reservoir, Wushantou Reservoir and Baihe Reservoir in Tainan to create more storage capacity, and improvements will be made to recycling facilities to make sure that every drop of water can be used two to three times, he said.
About 82 percent of the rain that falls in Taiwan goes to waste as runoff, while of the water that is stored, 72 percent is used by the agricultural sector, 9 percent by the industrial sector and 18 percent by households.
The government is to launch a water conservation program to reduce agricultural water waste by as much as 93.8 million cubic meters per year, or the total storage capacity of Nanhua Reservoir, Lai said.
Source: Taipei Times
