Macau is geographically highly exposed to extreme weather events. Its location in the Pearl River Delta makes it particularly vulnerable to rising sea levels. The territory is annually affected by typhoons with very strong winds and astronomical high tides that cause frequent flooding.
This vulnerability was all too evident in 2017 with Typhoon Hato, which flooded 25 per cent of the peninsula area, resulting in ten deaths and compromising the city’s essential electrical supply and functioning.
Macau has always had to deal with extreme weather events, but in the future, with climate change, they will become more frequent and severe. In this context, systematic planning that prevents, mitigates the effects, and reduces the social and economic costs of extreme weather events is essential and inevitable.
Comparing to 2017, we are better prepared on many levels. There has been a clear improvement in the quality of alerts and the mapping of risk zones. Finally, we have a new master plan that addresses these concerns, as well as several ongoing projects for rainwater pumping during peak situations. However, Macau still lacks a comprehensive solution and a general strategy to make the city more resilient. This requires rigorous and consequential studies.
I have been working academically and professionally on this issue for over ten years. I coordinated an international study on the Inner Harbour, published as a book in 2014, in which a series of urgent measures were outlined, with a focus on flood prevention, years before Hato.
For several years, I coordinated the urban design studio in the Master of Science in Urban Design at The Chinese University of Hong Kong. In the context of these studios, we studied various scenarios for the Inner Harbour, such as tidal barriers, seawalls, or sponges, and developed resilient urban plans for new land reclamation projects.
I also collaborated in an international workshop with the world’s top universities, sponsored by the government of Singapore, to test solutions for “future-proofing” public infrastructure over the next 20 years.
Between 2020-2022, I coordinated the project, commissioned by IAM to the University of Saint Joseph, for the general plan for the public space in the Inner Harbour south area.
From these various projects and experiences, I can conclude that there is no magic solution or single answer to this problem. A holistic approach is needed, integrating a set of complementary interventions, and redundancy is essential.
From the results of these various projects, we can observe that:
Tidal Barrier
It has a high cost, requires coordination with Zhuhai, and must be coordinated with other projects like the complementary retention and pumping system, which will protect the city until the barrier is built. Its main advantage is reducing intervention in the existing urban fabric. However, its technical effectiveness needs confirmation, which I am not aware of so far.
Seawall
It blocks the city’s proximity to the water, altering the entire coastline and comes with a very high cost, requiring intervention in the existing urban fabric. Even if it includes the metro and landscaping, it is a very heavy solution.
“Sponge”
If neither the Tidal Barrier nor the Seawall is implemented, a permeable solution (sponge) remains, where the city must absorb large amounts of water during peak situations. In this case, the retention and pumping system must be significantly oversized, and the existing urban fabric must be adapted to absorb water and withstand future floods. It must be complemented by many specific interventions to reinforce the coastline and adjacent structures.
Any of these solutions is complex and requires the coordination of multiple interventions to create a coherent and resilient system. We are talking about a fundamental safety issue for the social and urban development of Macau.
We must begin with a feasibility study that tests different scenarios with different solutions, considering multiple factors such as effectiveness, implementation, cost, maintenance, environmental impact, and urban quality.
Individual and comparative studies of various solutions are necessary to rigorously determine the best option. Once the most suitable solution is chosen, it must be designed and implemented consistently.
In addition to the fundamental infrastructure solution, there are several smaller-scale solutions that can and should be implemented in each detailed plan. We need to significantly increase the area of permeable pavements and green spaces throughout the city to absorb water and reduce its concentration during peak periods.
An integrated water retention system, distributed throughout the territory with a much higher capacity than historical maximums, is also necessary. Planning and incorporating redundancy into these various systems is crucial.
Finally, each new construction must be prepared to withstand and contribute to the resolution of the overall problem, with the overarching goal of creating a resilient city focused not only on problem-solving but also on urban quality and the quality of life of its residents.
*Architect and urbanist
