Sun, Mar 22, 2015 page3

• FEATURE: Water utilization methods panned

  • By Sean Lin / Staff reporter
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  With phase-three water rationing set to take effect next month in light of a prolonged water shortage, environmentalists and academics urged authorities to tackle the underlying problems surrounding the management of the nation’s reservoirs and reform their water utilization policies.

  Phase-three water rationing will be carried out by suspending water supply to Taoyuan, as well as New Taipei City’s Banciao (板橋), Sinjhuang (新莊) and Linkou (林口) districts, two days per week in rotation. State-run Taiwan Water Corp said that about 116 households and companies will be affected by the restrictions.

  Commenting on the nationwide water shortage, environmentalist Lin Chang-mao (林長茂) said the crux lies in the authorities’ poor management of the reservoirs, which has resulted in a buildup of heavy sediment in the reservoirs’ basins.

  With the exception of the Feitsui Reservoir (翡翠水庫), which is managed by the Taipei City Government, reservoir administrators have allowed unlimited access to tourists and restaurants in the reservoirs’ catchment areas, Lin said.

  Official statistics showed that sedimentation in the Shihmen Reservoir (石門水庫) in Taoyuan, inaugurated in 1964, exceeded 30 percent of the facility’s water storage capacity last month. In contrast, sedimentation in the Feitsui Reservoir, completed in 1987, was less than 7 percent.

  As a result of unrestrained tourism, ferries operating in the reservoirs’ catchment areas set off ripples that spread to the reservoirs’ walls, continuously washing down tiny bits of dust and mud from the basins’ banks, thereby exacerbating the sediment buildup, Lin said.

  The number of visitors to the Feitsui Reservoir is strictly limited, with just a couple of thousand people allowed access to the site every year, while tourists visiting the Shihmen Reservoir each year number in the millions, he said.

  Lin called on authorities to ban tourism during low-flow periods to ease sedimentation, as source management is the key to easing sediment buildup.

  Promoting tourism at reservoirs also pollutes drinking water, he said.

  “Tourists used to defecate and urinate in the reservoir’s catchment areas. The waste and the water from washing dishes at restaurants in the area all run into the reservoir. Back in the day, reservoirs had large available storage capacities, with enough water to dilute the sewage, but nowadays their storage capacity has shrunk considerably,” he said.

  Furthermore, man-made pollution causes eutrophication downstream of the reservoirs’ basins, triggering harmful algal blooms, during which traces of algal toxins are released into the water, he said.

  Citing findings by Academia Sinica research fellow Wu Chun-tsung (吳俊宗) in a study published in 2012, he said common algae due to eutrophication include microcystis, which has been discovered at reservoirs across the nation and induces gastroenteritis and liver cancer.

  Although the concentrations of microcystis found was not very high, the alga proliferates at an explosive rate and would pose a great threat to public health if water quality continues to deteriorate, he said.

  Other problems that contribute to heavy sedimentation include the wrong choice of plants grown upstream of reservoir basins, Lin said.

  “Farm plots and bamboo groves are often seen upstream of reservoirs, resulting in poor soil and water conservation. This type of vegetation has a poor water holding capacity and also adds to the sediment buildup whenever there is a downpour,” Lin said.

  National Pingtung University of Science and Technology professor Ting Che-shih (丁澈士) urged the government to change its current ways of utilizing water resources, saying that it should take advantage of groundwater.

  He said that surface water and water stored in reservoirs are more turbid during high-flow periods and are not fit for supply; therefore, groundwater should be the main source of water supply and reservoirs should focus on storing water during this season.

  In doing so, reservoirs would have been replenished by the low-flow season from November to April every year, ensuring an abundant water supply, he said.
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