by Jia-Jheng Yeh
The rainy season in Taiwan in 2020 was rather short, and there was no typhoon landing or approaching during the typhoon season, which caused serious water shortages at the beginning of 2021. Although the increased rainfall during May and June, the rainy seasons, greatly eased the crisis, the situation still serves as a reminder that people should value the water available now.
Dredging to raise reservoir capacity
Every year, Taiwan enjoys the accumulated rainfall induced from typhoons, rainy seasons, and the Northeast monsoon, but Taiwan’s rivers, flowing toward the east or west, are fast-flowing due to their short length and steep slopes, leading to the small amount of water reserved in the reservoir. Also, heavy rains bring large amounts of mud into the reservoir, where silt accumulates over time. Therefore, the storage capacity of reservoirs is reduced, leaving smaller water supply. According to statistics from the Water Resources Agency (WRA), MOEA, one-third of the reservoirs in Taiwan have faced accumulating silt, so there is a need for dredging. Dredging can be carried out in different ways, such as building flood dams, flattening riverbeds and slopes, constructing safe drainage facilities, etc. Yet, these methods are only buying time, instead of solving the problem at its root.
Water recycling as a new source of water
To ease water shortages, reusing wastewater has also become a promising option.
Take China Steel, one of the companies using the most water, for instance, a large amount of water is required for cooling, dust washing, and rust removal for steel production. Water shortages will affect the amount of production, and if worse, the equipment can be damaged, which is a huge problem for the entire production line. Since 2018, China Steel has built a wastewater recycling demonstration plant, the very first sewage treatment plant in Taiwan. With this new facility, sewage can be transformed and properly reused again.
Forests for water retention
The large amount of sediment brought by rivers is a major cause of water and soil loss. If the rain received exceeds the soil capacity and water flows faster than the soil can absorb, the water can still overflow, even if the maximum amount of water that a given soil can retain has not been reached. Forest restoration and conservation can help reduce disasters involving mud and debris. Also, it can increase water sources, reduce water usage, and recharge groundwater, all of which can boost the effect of water retention.
Due to climate change, the amount of water available is declining, which even shortens the lifespan of storage dams. Despite the situation, as long as the government and the people work together on the renewal and maintenance of water conservancy infrastructure, there can be changes made to our environment and ecosystems.