Guidelines adopted for artificial wetlands in urban environments

Published: 20 June 2014

The creation of artificial wetlands in concrete drainage channels in tropical cities can improve water quality. The conditions for these artificial wetlands have been tested and adopted in recent months by Deltares in Singapore. A pilot wetland measuring 50 x 4 metres will be created in a channel in Singapore in the near future, giving the city the first project of this kind in the world. Ellis Penning, the Instream Wetlands project manager at Deltares, will present the results in greater detail on 26 June at theEcohydraulics symposium in Trondheim.

Two goals achieved sustainably in a single operation

Concrete drainage channels are common in tropical cities. During the rainy season, extremely large amounts of water are drained out through the channels, preventing flooding. Singapore wants to improve the appearance of the channels, and also to enhance water quality. Creating wetlands makes it possible to achieve both these goals sustainably in a single operation. Ellis Penning: ‘Together with NUS Deltares (the regional alliance of Deltares and the University of Singapore), we conducted tests in the Van Kleef Centre, the university’s research centre. We conducted experiments that allowed us to identify the most effective types of sand and vegetation.’

Correct design crucial

The next step was to come up with a design for the wetland. Ellis Penning: ‘The drainage channels have to be able to cope with extremely high levels of rainfall, even when the vegetation is in place and so the design has to be just right. If there is too much vegetation, the channel can overflow; if there is too little, the water will not be cleaned adequately. On the basis of the tests, we were able to establish a picture of all the factors needed to ensure the proper functioning of urban wetlands and we can now say whether this is a feasible option in any given location.’

 

Opstelling van de proef in het Van Kleefcentrum

Test array in the Van Kleef Centre

The pilot study is being conducted on behalf of the Public Utility Board of Singapore and in collaboration with NUS Deltares.