Achieving Successful River Restoration in Dense Urban Areas: Lessons from Taiwan

Abstract

A paradigm shift in river management practice is underway, from a hard engineering-dominated emphasis that endeavours to control water, to a multi-functionality-framed approach that strives to restore a river's ecology, scenery and ecosystem services. In Taiwan, the Laojie River in Taoyuan City, where a channelized and piped urban river was recently transformed into an accessible, linear green infrastructure feature, is widely regarded as the first extensive and successful river restoration project in Taiwan's densely-urbanized, flood-prone areas, yet its actual performance is rarely examined in any depth. Through in-depth interviews, fieldwork and a review of government documents, this paper presents findings on the practical factors involved in the practice of river restoration and their implications for urban river management. First, local people support river restoration with de-culverting, but potential flooding is a concern that results from different flood-risk perceptions and ineffective flood-risk communication between the government and public. Second, a mix of hard and soft edges to the watercourse improves the riverside landscapes in a densely-urban, flood-prone area. Third, due to a lack of basin-wide supporting sanitary sewer systems, a combination of on-site gravel contact oxidation treatment systems and riverside sewage-intercepting facilities still fails to improve the river water quality. Fourth, people's positive attitudes towards river restoration are largely associated with landscape aesthetics and recreational value, rather than water quality and biodiversity. It is revealed that using the Cheonggyecheon Stream in South Korea as a frame for river restoration seems effective in providing local people with an example of successful river restoration, based mainly on flood prevention and recreational and aesthetic improvement. Moreover, the effective flood-risk communication is mainly reliant on an intelligible presentation of related information to the general public. Practical, continuous and extensive public participation, with various types of involvement and resources along with a solid system of social objectives by which to assess the outcome, is central to the social aspect of river restoration.

Comparing the functional recognition of aesthetics, hydrology, and quality in urban stream restoration through the framework of environmental perception

“…The SPSS24 and XLStat were used for a hierarchical multilevel analysis (linear mixed‐effects model) for citizen survey results to examine the relationships between the comparative perceptions of residents regarding urban stream restoration and the image‐based visual survey data. In general, resident perceptions regarding stream restoration are usually shaped as an integrated format of functions based on landscaping, hydrological engineering, and environmental quality increase (Chou, ). These variables were selected from the literature review.…”

Nature-Based Solutions for hydro-meteorological risk reduction: A state-of-the-art review of the research area

“…One of the possible reasons is that large-scale systems are much more complex than small-scale systems. The most common large-scale NBS are wetlands (Thorslund et al, 2017b), river restoration (Chou, 2016), flood storage basins (De Risi et al, 2018b), preservation and regeneration of forests in flood-prone areas (Bhattacharjee and Behera, 2018) and making more room for the river (Asselman and Klijn, 2016;Klijn et al, 2018).…”

“…Another case study of a large scale NBS is the Laojie river project in Taoyuan City in Taiwan. The study focused on changing the channelised culverted flood-control watercourse into an accessible green infrastructure corridor for the public (Chou, 2016). The landscape changes resulting from this project have increased recreation activities and improved the aesthetic value in the area.…”

Implementation of Nature-Based Solutions for Hydro-Meteorological Risk Reduction in Small Mediterranean Catchments: The Case of Portofino Natural Regional Park, Italy

“…This program not only achieved benefits in terms of flood risk reduction, but it also produced other benefits, including improvements in spatial quality as well as habitat and biodiversity restoration [7,8]. Another case study is the Laojiee River Project in Taiwan, where the channelized watercourse was changed into an accessible green infrastructure corridor for the public, increasing recreation activities and the value of the area [9].…”