Multi-layered flood control network
Significantly influenced by a subtropical monsoon climate, often with heavy rainfall, coupled with low-lying terrain and tidal impacts, the risk of flooding is a major concern for Guangzhou during its development. However, its extensive river system also offers unique advantages, encompassing transportation, landscape, ecology, lifestyle, and economic activities.
Because water is both a resource and a constant challenge, Guangzhou's riverside urban development strategy is not simply about beautifying the riverbanks. Planning must simultaneously address multiple requirements, including flood control, rainwater drainage, ecosystem protection, and the creation of public spaces.
Guangzhou adopts a sponge-like approach, where the city is designed to absorb, retain, and regulate rainwater, rather than simply collecting and removing it from the city. A notable aspect of this approach is the integration of water safety requirements directly into the design of public spaces.
Urban planners argue that flood control doesn't begin with building higher walls along rivers, but rather with creating more space for water within the urban structure. Therefore, in its drainage and flood control plan for the period 2022-2035, Guangzhou has identified the construction of a four-component system: "green - blue - gray - management".
In this context, green includes trees, parks, and water-absorbing spaces. Blue represents rivers, lakes, canals, and water reservoirs. Gray includes pipelines, pumping stations, and drainage systems. Management encompasses monitoring and operating the entire system. The city aims to create a multi-layered flood control network capable of responding to heavy rainfall events with a recurrence interval of up to 100 years.
The unique aspect lies in the fact that a single space can serve multiple functions simultaneously. A low-lying area doesn't necessarily have to be leveled for construction; it can become a temporary water reservoir during heavy rains. A park isn't just for recreation. The trees, soil, and water bodies within it can absorb, retain, and slow down runoff. A riverside promenade not only enhances the landscape but can also be designed to channel water to regulating areas.
The city therefore does not try to remove all rainwater from the urban area as quickly as possible, but rather seeks to slow down the flow, disperse the water, and increase the self-regulating capacity of the system.
This organizational approach is particularly suitable for an urban area with a dense network of rivers and canals, simultaneously affected by heavy rainfall, river levels, and tides. In different areas, the solution is also adapted to topographical conditions. In the northern region, where upstream areas are located, emphasis is placed on water regulation and storage capacity.
The central area focuses on addressing flow bottlenecks and improving the sewer network and drainage lines. Meanwhile, the western and southern areas, with their tidal-influenced river networks, utilize existing ponds, lakes, and channels to regulate rainwater runoff.
In other words, Guangzhou isn't looking for a "single key" to solving its flooding problems. The city has built a system where each layer takes on a specific task: trees and soil help retain water; lakes, ponds, and low-lying areas can accommodate larger volumes of water; rivers and canals carry water; and the system of sewers, pumping stations, and irrigation works handles situations where natural solutions fail.
From water flow management to comprehensive riverside spatial planning.
The multi-layered approach to flood control has laid the groundwork for a broader shift. Guangzhou no longer views the riverbanks merely as areas needing protection from flooding, but as urban spaces requiring comprehensive planning. In 2022, the city released a draft plan for high-quality development along the Pearl River, studying approximately 100 km of the river, with a focus on 75 km in the central area, spanning nine districts. The scale of the study shows that the approach is no longer limited to individual parks, sections of embankments, or separate projects, but aims to organize the entire riverside urban strip into a unified system.
Notably, this plan does not place landscape or economic development as separate objectives. The contents are organized simultaneously across eight dimensions: public space, ecology, culture, transportation, safety, urban image, innovation, and industry. The goal is to enhance the role of the Pearl River as a spatial axis connecting the city's functions, bringing the riverside area closer to urban life, and creating additional impetus for economic development.
This represents a significant shift in planning thinking. A safe riverbank doesn't necessarily have to be one isolated from the community. Nor does an ecological space have to be separate from economic activities. Conversely, if properly organized, the same strip of land can simultaneously serve the functions of flood control, green space creation, transportation connectivity, urban memory preservation, and attracting service and cultural activities.
This planning approach also helps address a common problem in riverside cities: the fragmentation of riverbanks. Instead of allowing each area to develop independently, Guangzhou aims to create linkages between different sections of the riverbank while still preserving the unique characteristics of each region.
In the planning, the 75 km central area is envisioned as a unified spatial strip but with different functions and development forms. The riverside areas are oriented towards forming distinct "brands" based on their advantages in culture, ecology, transportation, innovation, and industry.
From this point on, the river is no longer just a natural boundary dividing the city. It becomes an "axis" for reorganizing urban space. Pedestrian walkways, green spaces, riverside parks, and community centers are connected to transportation and economic development areas.
Areas of historical value are placed in relation to urban renewal and development projects. Meanwhile, safety, ecological, and resilience requirements are incorporated from the planning stage, rather than being addressed as issues arising after the city has taken shape.
This is also why the 2022 Pearl Riverfront master plan goes beyond a mere landscape improvement scheme. It shows Guangzhou's attempt to change the perception of the riverfront's value, from a strip of land under development pressure to a space that can simultaneously create environmental, social, cultural, and economic value.
When these functions are placed within the same planning structure, urban development goals are no longer simply a choice between "protection" and "exploitation," but rather aim to find ways for these two requirements to support each other.
From flood control to riverside spatial organization, Guangzhou is demonstrating a different approach. There, the city is not seeking to separate itself from the river, but rather proactively adapting, living in harmony, and enhancing the values that the river brings.