• SL Land Development Corp. Environmental and Sustainability Scientist Dr. Chethika Gunasiri on the importance of preserving the lungs of the Colombo City

Colombo is one of the first Cities in the world to be named a Ramsar Wetland City. This title bestowed on Colombo in 2018 was in recognition of the relationship between the City and the wetland complex and how it has integrated into urban development. However, there is little emphasis on the importance of urban wetlands in the survival of the city. Essentially, it is with wetlands that we are able to create a resilient and inhabitable city, not just for the present but for the future as well.

On Kaleidoscope this week was Sri Lanka Land Development Corporation Environmental and Sustainability Scientist Dr. Chethika Gunasiri, who has a Doctor of Philosophy degree in Sustainability Science and has more than 10 years’ of experience in urban ecosystem management. She was one of the experts involved in the Colombo Wetland Management Strategy and the Ramsar application. Here, she explains the reasons as to why Colombo’s wetlands are truly the lungs of the City and highlights the need for an acute consciousness of the importance of these wetlands in the context of urban development.

Following are excerpts of the interview:

Q: For city people, ‘wetlands’ are mysterious bodies of nature. What is the importance of urban wetlands? What do they do?

Most often, we are unaware of our surrounding environment. This is why urban wetlands are not too popular, because people do not know much about them. The urban wetland is located in a city or in a peri-urban area and it is crucial for the survival of the city as it absorbs rainwater and stormwater, which means that it prevents the flooding of the city. Wetlands also have the ability to purify the polluted water in the city. They filter the air because they have a high level of vegetation. Wetlands give multiple opportunities for urban recreation and tourism and, most importantly, these are the only green spaces in most cities which provide refuge for the urban wildlife. Urban wetlands therefore perform an expansive range of functions and are considered the most productive ecosystem among all ecosystems, due to their structure and nature.

Q: It sounds like the wetlands are the lungs of the city. Since you are involved in the restoration, management, and proper use of urban wetlands to achieve sustainable city development, could you please explain what wetlands have to do with city development?

A: This year (2023), the theme for the Ramsar Wetland Day, which fell on 2 February, was ‘wetland restoration’, because the United Nations has declared this decade to be a ‘decade of restoration’. We know that cities house thousands of people in very small spaces. If we take the earth’s surface, only 2% of it is taken up by cities, but cities produce 70% of the global waste and utilise 70% of the world’s natural resources. Therefore, it is very important to integrate the wetlands’ functions with the threats that the cities are facing. These threats are a consequence of urbanisation and pollution. We should see urban wetlands as solution providers by integrating the wetlands’ main functions into city development. One of the major ways that cities have applied this tactic is via ‘nature based solutions’, i.e. finding solutions for issues through nature. This is because it is sustainable. Nature is a complicated network and has all the solutions for the problems that humans have created. This is why many cities in most countries are moving towards this, integrating the functions of the urban wetlands into city development. However, Sri Lanka must have proper planning and designing in order to identify the functions that urban wetlands provide and to figure out how to actively integrate these functions into city planning.

Q: For those unfamiliar with the Colombo Wetland Complex, what would you say it is?

A: The Colombo City is naturally located in the downstream of the Kelani River basin and is a natural flood plain area. It is a City that is also located on the mosaic of wetlands now known as the Colombo Wetland Complex. This complex has around 36 patches of wetlands, which are interconnected with the Colombo canal network – a network that is entirely man made. The total area of the Complex is approximately 1,900 hectares and the City is entirely dependent on the functions provided by the Colombo Wetland Complex. The area is also called the Colombo Hydrological Area. The population in this area is around 2.4 million and it is the most important area of the country, because the Commercial Capital and the Administrative Capital are located within the Complex. Do not forget that 50% of the country’s gross domestic product is earned in the area where the Complex is located as well. Due to these reasons, we can definitely say that this is the most significant Wetland area in the country.

Q: What can we do then to protect our wetlands?

A: The main challenge for urban wetland conservation is the lack of people’s awareness. People have no idea that their lives are completely dependent on urban wetlands, which are often found in one’s own backyard, in one’s neighbour’s garden, or within their neighbourhood itself.

Due to this lack of awareness, there tends to be illegal filling, encroachment, and garbage dumping into wetlands and waterways. It is vital therefore for people to have proper awareness about how wetlands can make cities liveable and how our whole lives depend on them. Citizens can become actively involved in wetland restoration and management by cleaning our wetlands and waterways and refraining from dumping garbage into these spaces. ‘Citizen science’ is an emerging science actively used in urban wetland management around the world. This is where citizens get involved directly as scientists for data collection. As wetland managers, we need updated information about wetlands. Unfortunately, we do not have sufficient resources to do that. Because urban wetlands are always changing due to their location and due to human pressure, citizens, especially students and children, can get involved in gathering scientific information from wetlands that we need for conservation. Therefore, citizens have a crucial role to play in conserving wetlands.

Q: What consequences would we face if we were to lose our wetlands?

A: I would simply say that Colombo would not be a liveable City without wetlands. A total of 37% of rainwater flows to the Colombo metropolitan area and is absorbed by the Colombo Wetland Complex, so imagine what would happen if there were no wetlands to absorb that water? Even the smallest amount of rain would flood the City. A while ago, the Government did a quantification to derive the economic value of wetlands. The findings showed that the Colombo Wetland Complex provides Rs. 15 billion worth of flood saving for the City, every year. The wetlands also perform Rs. 2 billion worth of wastewater treatment. Without these functions then, we would have to spend Rs. 2 billion every year just on waste water alone.

At present, 65% of the Colombo canal network is in very bad shape. However, even though the wetlands are highly degraded at the moment, they are still performing their functions. Without wetlands in Colombo, the City would face frequent floods, water pollution, and related health issues, as well as increasing stress levels on the part of the citizens, due to increasing urbanisation. Simply put, without wetlands, Colombo will be an unlivable place.

Q: Humans need to look after their lungs to survive. Similarly, we need to look after our cities’ lungs if the cities are to survive, do we not?

Definitely. As humans, we are very conscious about our health. If we are not healthy, we cannot function efficiently. Likewise, when the wetlands are not performing to their optimum, the city falls sick and we do too, eventually. Therefore, it is our responsibility to look after the lungs and the kidneys of the city.

(The writer is the Host, Director, and Co-Producer of the weekly digital programme ‘Kaleidoscope with Savithri Rodrigo’ which can be viewed on YouTube, Facebook, Instagram, and LinkedIn. She has over three decades of experience in print, electronic, and social media.)