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Reservoir desilting project to ensure water supply: Lai

2018/01/28 17:37:27

Premier Lai Ching-te (賴清德, fourth left)

Tainan, Jan. 28 (CNA) A recent project to remove silt from the Zengwen Reservoir (曾文水庫) and extend the reservoir's life demonstrates the government's resolution to ensure a stable water supply for industry, Premier Lai Ching-te (賴清德) said Sunday.

Speaking at a ceremony in Tainan marking the completion of a desilting tunnel connected to the reservoir, Lai said the project is expected to remove large amounts of sediment from the reservoir.

The reservoir, which is the main supplier of agricultural water in Chiayi and Tainan, has faced serious sedimentation problems over its 44-year existence, especially following Typhoon Morakot in 2009, according to Lai.

One of the deadliest typhoons to hit Taiwan in recent history, Morakot led to the buildup of 90 million cubic meters of sedimentation in the reservoir.

That was why the government initiated the desilting tunnel project, which was completed in November 2017, Lai said.

Based on the principle that water always seeks its own level, the desilting tunnel is connected down to the existing bed level with an elephant-trunk steel pipe, and serves as an outlet draining sediment-laden water, known as turbidity currents, as they rise out through the tunnel.

The structure has a desilting capacity of 1.04 million metric tons per year, which translates to an increase in 55 million cubic meters of water of capacity, Lai said.

The reservoir now has a maximum of 460 million cubic meters of water, well off its original capacity of 790 million metric tons of water, according to the Water Resources Agency's South Region Water Resources Office.

Lai also praised the tunnel for using an eco-friendly engineering design and for avoiding any major accidents during its construction.

As a former Tainan mayor, Lai said all Tainan residents are extremely happy to see the project completed on schedule.

According to Lai, because of the island's geography, 82 percent of the water that falls as rain either flows directly to the ocean or is lost to evaporation, leaving only 18 percent for human use.

Of that, 72 percent is channeled to agriculture, 9 percent goes to industrial use and the balance is for household use.

Lai said many Taiwanese businesspersons have expressed concern over the nation's water supply, including Morris Chang (張忠謀), founder and chairman of Taiwan Semiconductor Manufacturing Corporation (台積電).

The government has confidence, however, that it can ensure a stable supply of water to the industrial sector and resolve regular shortages as reflected by the reservoir project, Lai said, and he urged more companies to invest in Taiwan.

The NT$4.1 billion project started in March 2013 and was completed in November 2017, according to the Water Resources Agency's South Region Water Resources Office.

The project is expected to save the country NT$693 million annually in spending on the removal of sediment from the reservoir, according to the office.

(By Chang Jung-hsiang and Joseph Yeh)
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