Wetlands save Colombo millions through a range of ‘ecosystem services’
The Colombo Wetland Complex (CWC) which includes 20 square kilometres of freshwater marshes, lakes and paddy fields in the city, stretches around the Diyawanna lake like an emerald necklace, extending to areas such as Beddagana, Thalawatugoda, Kotte, Kolonnawa and up to Talangama and Ambatale.
It has been estimated that – similar to damages suffered in the massive floods of November 2010. The CWC provides refuge for 39 percent of the storm water – storing and then slowly releasing the excess water over a long period of time. In doing so the wetlands help maintain soil moisture balance.
There are also a host of other “ecosystem services,” says Chethika.
More than 50 percent of the city falls within the catchment of the CWC, allowing Colombo to enjoy a kind of natural air conditioning. - the wetlands reduce the incidence of cardiopulmonary and respiratory diseases, coughing, bronchitis, and lung cancer.
The combat pollution in the water as well. Research conducted while preparing the Colombo Wetland Management Strategy (WMS) revealed that 65 percent of the canal network in Colombo carries water of poor quality – but that the water tends to be cleanest around the Parliament lake area, thanks to the wetlands which act as filters. Areas like Wellawatte, where the wetlands have been filled up, have noticeably poorer water quality.
Even more important is how . The WMS highlighted how locals relied on water from wetlands to cultivate vegetables, edible herbs, yams and other crops when water levels are low or during off-paddy seasons. The wetlands supported subsistence fishing, and offered spaces for cattle to forage.
The delegation from the Maldives Climate Change Adaptation Project (CCAP) engaging with local officials and experts in an "island to Island" knowledge exchange. Photo Credit: Climate Change Adaptation Project PMU
. An estimated 60 percent of such local households directly benefit from livelihoods and products derived from the wetlands.
Why recreate, when you can protect?
In some parts of the city, up to 60% of wetland extent has been lost since the 1980s. Programs such as the Metro Colombo Urban Development Project (MCUDP) supported by the World Bank are rushing to stem the tide, creating spaces such as Diyasaru where the wetlands can be protected.
This is a conservation effort with tangible rewards. Today, tourists seldom linger in the crowded capital. Restoring and opening up the wetlands may give them a reason to stay. In fact, it is estimated that the wetlands could generate about Rs 2 billion annually for the city if their recreation potential was tapped.
Sri Lanka need only look to other cities to realise it makes complete sense to preserve its wetlands. Take the London Wetland Centre – . In Hong Kong, the government created a 64-hectare wetland in the middle of the city to recreate nature and nature’s services. These have become major attractions in these cities. Colombo doesn’t have to spend millions doing the same – all it needs to do is protect the bounty it already has.
Wetlands for a sustainable Colombo
People think of wetlands as a barrier to development or as a kind of wasted business opportunity, where every perch of land should be filled up, say Chethika, explaining that working at the Land Reclamation and Development Corporation means that she is very pro-development, but understands that if it is not sustainable Colombo could become unliveable.
“We don’t want to stop development. When it comes to wetlands, we cannot put up a fence around them. We have to integrate them into people’s lives so they can support livelihoods and also incorporate them into tourism.”
Colombo has been presented with a unique branding opportunity, she emphasizes. “This is our uniqueness. We don’t want to become another shopping destination, we can’t be KL or Singapore. We have to use what we have and our wetlands can help us build a unique, sustainable city.”