Can wetlands prevent murder?


People from all over the city come to enjoy the fresh air and cooler climate that urban wetlands such as Talangama Tank provides.

Rose-ringed parakeet
Pics courtesy: Sanjiv de Silva and Madeline Dahm/IWMI

Can wetlands prevent murder? Of course, if you consider the fact that wetlands promote better sense of civic responsibility, offer recreational and socialization opportunities thereby relieving stress of the urban dweller, it could affect the crime rate. And it might just be an effective deterrent to murder.

By Sajitha Prematunge

Wetlands provide a variety of ecosystem services that would not be economically viable to provide by artificial means. Nearly 90 percent of these wetlands contribute to urban food supplies through the production of rice, vegetables, and dairy and poultry products as well as through fishing and gathering of native plants. One major function that wetlands fulfil is flood mitigation. With a capacity to store enough water to fill 27,000 Olympic-size swimming pools the Colombo wetlands complex plays a vital role in flood mitigation. Wetlands also work to reduce heat through evaporative cooling and purifies air by trapping airborne pollutants.


Any school kid knows the value of a wetland, but how do you put a price tag on natural resources and the ecosystems function they perform that experts claim are priceless, yet are intangible? This is where environmental valuation comes in.

As economists and urban planners are seen as the enemy of wetlands, this novel way of valuing wetlands as ‘urban infrastructure’ coming from Economist Lucy Emerton, Environment Management Group, SOAS University of London, is sure to attract the attention of Sri Lankan policy makers.

Economists argue that wetlands are unproductive land that can be put to better use, specially in the urban setting where land prices are skyrocketing. In fact, most of them would like nothing better than to convert wetlands to malls and luxury apartments. "This has been the dominant thinking, that wetlands are a useless, wet, smelly, unhealthy waste of space. But this is not the case," said Emerton. It’s all about money. In an economic perspective wetlands actually save a lot of money for city dwellers as well as governments.

Governments, urban planners, economists and engineers often make decisions based on economic grounds. They could care less about biodiversity. Emerton’s role as an environmental economist is to make a business case by helping to calculate the costs and benefits of natural systems. In short put a price tag of an intangible ecosystem service.

"Investing in the conservation of wetlands adds substantial value to the urban economy, while avoiding costly losses and damages," reiterated Emerton. Valuing wetlands as urban infrastructure aims at forcing decision makers to look at the services of a wetland, recognize them for their economic services and accept the fact that rather than being a barrier to urban development they are key infrastructure required to sustaining city life.

"What planners and governments care about is how to deliver services to the population," pointed out Emerton. And what better way than a natural system to provide those services at a fraction of the cost. For example, wetlands are highly efficient water purifiers and it would cost thousands of dollars to provide this particular service artificially.

Emerton said that ecosystem services cannot be valued in traditional economic methods. Ecosystems are valued best using indirect methods. "Flood control cannot be valued using market prices. You can’t buy a cubic meter of flood control. But you can value flood damage incurred had the wetland, which provides the ecosystem service of flood retention, not been there, such as damage to property, area affected, flood frequency and magnitude. "Such methods calculate the damages avoided," pointed out Emerton. "For example, if the flood damages amount to 10 billion rupees a year and there are 10 hectares of wetlands, then every one hectare of wetland is worth one billion rupees."

While admitting that Sri Lanka has shown promise in valuing ecosystems, Emerton said that it would take some time for the numbers to kick in. She also warned that continuing business as usual will cost water users, fisheries, the tourism industry and Government budgets almost RS 35 billion over the next 25 years. Wetlands generate economic services, facilities and amenities worth approximately Rs 723,000 ha/year. The assessed economic value of flood control is Rs 1,485 million a year, water purification value Rs 521 million, recreation value Rs 16 million, energy supplies Rs 24 million, fisheries productivity Rs 80 million, support to agriculture Rs 93 million, adding up to a total of a staggering Rs 2,219 million a year.

"It’s not cash we can put in our pockets, but each one of these rupees represents a value that somebody else doesn’t have to spend, somebody catches in their fishing net, cultivates in fertile soil, experiences watching birds, having clean water," said Emerton, reiterating the significance of valuation. "Infrastructure is not just bricks, pipes and buildings. It also includes species, plants and hydrological systems. Wetlands are urban infrastructure."

Conservation Vs Reclamation

Much of the wetlands were reclaimed while under British rule. In the 1980’s large masses of wetlands were reclaimed to make way for the administrative city, Sri Jayawardenepura Kotte. The trend was to reclaim and develop them, hence the establishment of Sri Lanka Land Reclamation and Development Corporation (SLLRDC).

Though the SLLRDC was established with misguided intentions, the institution is now at the forefront of the efforts to preserve wetlands. Diyasaru Park and Beddagana Park are both managed by the SLLRDC. SLLRDC is also looking to use the Colombo water ways for boat transportation to beat Colombo traffic! The first of such transport channels will be introduced in a public private partnership venture, from Wellawatta to Diyatha Uyana and the second will utilise Beira Lake from McCallum Lock Gates to Ministry of Mahaweli Development with the help of crew boats provided by the Navy, informed Dr. N.S. Wijayarathna, Deputy General Manager Wetland Management, SLLRDC. The 45 kilometres of canal in the Colombo catchment may one day be incorporated into this transport system.

The Department of Wildlife Conservation has also come into the fold by submitting an application for the Wetland City Accreditation, a scheme directed towards highlighting and strengthening a positive relationship with wetlands through increased participation and public awareness in municipal planning and decision-making. Fingers crossed Sri Lanka will be bestowed the honour of being awarded the first wetland city among many other cities in the world at the 13th Meeting of the Conference of Parties, to be held in October in Dubai. "This will be vital to branding of Colombo," said Wijayarathna.

"The Colombo wetlands complex performs vital hydrological functions such as flood control. In fact, 39 percent of storm water is retained by these wetlands only 20 square kilometres in extent. If we were to provide this service artificially it would be very costly," explained Wijayarathna.

Sri Lanka’s Wetland Management Strategy, funded by the World Bank, carried out between 2015 to 2016, identified many benefits of the Colombo wetlands complex other than flood retention. "It identified that the city’s heat was being regulated by the wetlands." If you have ever taken the Sri Jayawardenepura Mawatha, over the Diyawanna Lake past the Diyatha Uyana, you have probably felt heat regulation first hand. The cool breeze that hits you just as you exit the building complexes is hard to miss. Wetlands and associated vegetation store twice as much carbon dioxide than other areas.

"Storm water, carbon dioxide and heat are the stress factors associated with the city," pointed out Wijayarathna. "The recreational options that wetlands afford such as jogging tracks and parks and the aesthetic appeal of wetlands relieve human stress. Without the wetlands no business can function in the city."

Wijayarathna reiterated that such intangible values or what’s referred to as indirect use values in valuation terms are in fact, incalculable or difficult to calculate at best. He pointed out that Singapore is spending millions of dollars to recreate the wetlands they had lost to development. "Ecology and engineering should go hands in hand to achieve sustainable development," emphasised Wijayarathna.

"If wetlands promote better sense of civic responsibility, offer recreational and socialization opportunities thereby relieving stress of the urban dweller, it could affect the crime rate," said Emerton. And it might just be an effective deterrent to murder.


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