Under the impact of southwesterly flow and stationary front starting from 1st June 2017, the extremely torrential rain has caused flooding in multiple areas, including Anle district in Keelung, Jinshan, Shihmen, Tamshui, Sanjih, Bali district in New Taipei City. The area of flooding has accumulated to 122.5 hectares, 0.3-2.5 meters in-depth, the time of flooding is between 6-12 hours. In response to the flooding damage caused by the extremely torrential rain, WRPI has reviewed the planning of drainage system of Dawulun Drainage, for the reference of following improvement project.
Considering the development along with the drainage, the closeness between buildings and waterway, the drainage improvement project of Dawulun Drainage finds it difficult to expand the channel. Thus according to the flooding situation, the improvement project is divided into several phases. The projects are as Figure 1. In the short-term, it is aimed to solve the channel bottleneck, make the water flow smoothly and further solve the flooding situation in industrial areas. The middle-term would take measures such as flood detention in the upstream, improvement of the downstream channels and critical bridges, to reach the protection standard covering all the watershed of Dawulun Drainage. In the long-term, focusing on the highly-populated and industrial areas, the objective is to enhance the protection standard and to avoid the damage of people’s lives and property. In sum, this project would be accomplished following the concept of comprehensive water management.
Figure.1 Dawulun Drainage improvement scheme