Compact spaces go big on runoff treatment

Integrated and mixed development projects amongst the 14 new certified projects, bringing ABC Waters Programme a step closer to mainstream

Developments with a small footprint have the potential to go ‘big’ in cleansing rainwater runoff by incorporating national water agency, PUB’s Active, Beautiful, Clean Waters (ABC Waters) concept in their projects. This was demonstrated by two integrated developments, Kampung Admiralty and Oasis Terraces, which received the ABC Waters certification today for extensively integrating ABC Waters design features as part of their designs. Another outstanding project – Paya Lebar Quarter – is the first mixed development from the private sector to receive this honour.

A total of 14 outstanding projects from the public and private sectors received the ABC Waters certification today at the Seminar on ABC Waters – Creating Sustainable Solutions for Liveable Cities, held in conjunction with the Singapore International Water Week 2016, from Guest-of-Honour, Dr Amy Khor, Senior Minister of State, Ministry of the Environment and Water Resources & Ministry of Health.

Planning with ABC Waters in mind
Kampung Admiralty and Oasis Terraces, both public development projects by the Housing & Development Board (HDB), are the first integrated developments to receive the ABC Waters certification. With a relatively small footprint of about 1 hectare, both sites have creatively integrated ABC Waters design features such as rain gardens, cleansing biotopes and vegetated swales as part of the developments’ design. Kampung Admiralty, in particular, was conceptualised to feature a unique tiered design that showcases varied ABC Waters design features on different levels of the development within a limited site area. The result is that more than 30 percent of the total site areas’ rainwater runoff is detained and treated – a remarkable achievement for small sites due to space constraint.

Paya Lebar Quarter, developed by Lendlease Retail Pte Ltd. has innovatively integrated its internal drainage facilities and ABC Waters design features by creating a detention zone below its rain gardens. Besides detaining and treating rainwater runoff from over 30 percent of the total site area, the integrated drainage cells serve as a source measure to temporarily store rainwater, slow down surface runoff and reduce the peak flow of rainwater into the public drainage system. It is also the first mixed-use development by a private developer to receive the ABC Waters certification and the first private sector project to provide a detention tank below ABC Water design features.

Evolution of rain gardens (moving with the times)
As the ABC Waters Programme enters its 10th year, it continues to transform Singapore’s waterscape with more projects that enhance liveability and add value to our living environment. Besides working with various stakeholders to promote the mainstreaming of the Programme, R&D is a major component that PUB focuses on to make the Programme even more pervasive. To ensure the ease of implementation of ABC Waters design features like rain gardens, PUB, as part of a joint R&D project with the National University of Singapore (NUS), has successfully test-bedded the feasibility of “soakaway” rain gardens at four educational institutions1 and will be further rolling this out in another 6 schools2. The rain gardens will be built by 2017.

Unlike their conventional counterparts, “soakaway” rain gardens can be designed with only one filter layer, without the need for subsoil drainage pipes, nor connection to the drainage system. This straight-forward design facilitates easy construction and greater adoptability by the community as it is simple to implement and suitable for most sites. This increases the community’s adoption of ABC Waters design features within existing and new development sites.

Mr Tan Nguan Sen, Chief Sustainability Officer of PUB, said, “PUB is encouraged by the support from developers and professionals in sharing our vision and creatively applying ABC Waters design features within their development sites throughout these ten years. We will continue to improvise and innovate, finding better and simpler ways to implement the ABC Waters concept to all segments of the community – from private developers, public agencies to schools. We will strive towards creating a City of Gardens and Water through ABC Waters, thereby making Singapore more liveable and sustainable.”

Growing pool of experts
With ABC Waters set to become a way of life, and more projects receiving ABC Waters certification, PUB and the Institution of Engineers Singapore (IES) have been working together to develop the industry’s competence through the ABC Waters Professional Programme. Since its launch in 2011, the pool of ABC Waters professionals registered with IES, Singapore Institute of Architects and Singapore Institute of Landscape Architects has grown to 50, comprising a mix of engineers, architects and landscape architects. These qualified individuals play an active role in designing, overseeing the construction of, and developing a maintenance plan for ABC Waters design features.

One such registered professional is Koh Jiann Bin, a landscape architect who has been involved in 23 ABC Waters projects, including notable ones at the Oasis Terraces and at the Jurong Port. He said, “Water has been shaping the landscape long before there were landscape architects and we have a lot to learn from it. Through ABC Waters, we gain insight on how to design with water in a more purposeful and sensitive manner, especially in our urban environment. When there is a new layer of understanding, new opportunities present and that’s what designers are excited about.”

At the Seminar on ABC Waters – Creating Sustainable Solutions for Liveable Cities held in conjunction with the Singapore International Water Week at Marina Bay Sands, professionals renowned in the field of urban design and liveability shared insights on ideas and challenges faced in applying and implementing ABC Waters design features, and how the ABC Waters framework helps to create a more liveable and sustainable Singapore.

1 The four “soakaway” rain gardens were test-bedded at Nanyang Junior College, Anglo-Chinese Junior College, Dunman High School and NUS as part of a joint R&D project with NUS.
2 “Soakway” rain gardens will be built at Anglican High School, Hillgrove Secondary School, ITE College East, Pei Hwa Secondary School, Republic Polytechnic and West Grove Primary School.