Working with Beijing on its water eco-restoration plan

Submitted by Nitya Jacob | published 20th Sep 2022 | last updated 7th Apr 2023
Beijing's Water Eco-Restoration Plan
Beijing is one of the worst-affected cities

Beijing is one of the worst-affected cities

Introduction

People living in urban areas are increasingly exposed to the effects of climate change. In China, environmental pressures are manifest through water shortages. The Global Center on Adaptation has supported Beijing by providing advice in the area of water eco-restoration. Arnoud Molenaar, Chief resilience office of the city of Rotterdam, and Tony Wong, Chair of Water Sensitive Cities Institute Think Tank, shared their comments at this roundtable, moderated by Joep Verhagen, Program Lead of Water and Urban, GCA, and Chen Aiping, Regional Director of the China Office, GCA.

Molenaar spoke about how to achieve harmonious development between water and urban development, focusing on expanding green or ecological infrastructure in the light of space constraints in a city. Insights from Rotterdam showed how a city can transition to building felxibly and water as a benefit. Water is an important designing principle. When city planners design an urban area, they include water and adaptation experts to develop a holistic plan to address climate change.

Sports facilities can double as water buffers. One of Rotterdam's water squares can store up to 1700 m3 of rainwater. Then there are rooftops that have been transformed into multifunctional roofs. The key is, initiative for urban development follow from a holistic city vision instead of a specific cost-benefit goal.

Three principles

The following are three principles of water sensitive cities evolved from the so-called sponge cities:

  1. Cities as water supply catchments
  2. Cities providing eco-system services
  3. Cities with water-sensitive communities

It is about flood management, water pollution control and trying to mimic the natural hydrology as best as possible, said Tony Wong. If infiltration of rainwater is not possible, think of retention where water is captured in landscapes for reuse. Sponge cities are about aligning urban development with hydrological processes.

City resilience needs to be balance with ecological spaces. Li Hengyi, Beijing Institute of Water, said. Rotterdam has developed models to understands the risks of flooding. Molennar said these models can predict floods 100 years into the future and determine how to build now. For instance, 11 km of embankments and other areas were identified that could be transformed into agreen spaces by creating wetlands.

Water sensitive cities should match the hydrological dynamics of the area. Wong said cities need to allow for landscapes that will flood and impound water ins ummer. In winter these would become a nice natural landscape that served a different purpose. In Beijing 90% of rainfall occurs in a few months. In the wet season you store the water and pump it out in the dry season. It helped the groundwater recover.

Another issue was balancing shoreline vitality with ecological health. In Rotterdam, said Molenaar, biodiversity has become an indicator of urban health. The city council identified opportunities for win-win action, for example the sedminent from dredging the river can be used for shoreline restoration. Wong said the space around roads, railways, etc., can be designed as ecologically embedded landscapes with green-blue corridors. The green corridor could also be a passage for floodwater. They need to be defined by where you want floodwater to go.

It is important to develop water literacy among the city's population, both experts said, for both citizens and politicians, said both the experts. In this dialog, GCA proved to be an effective solutions broker for urban water restoriation in Beijing.