Towards better urban water management

TODAY, as more than half the world's population live in cities, Asia is expecting unprecedented growth. By 2030, megacities of 10 million inhabitants or more will be located primarily in Asia.

While urbanisation is synonymous with economic growth, it can often do more harm than good if we do not have the proper infrastructure to sustain the rapid development. As epicentres of human activities, cities see intense production and consumption. These activities use huge quantities of our limited natural resources while contributing to climate change.

One of the most critical resources under increased stress in urban cities is water. The issue is even more acute in the Asia-Pacific, with the region being home to almost two-thirds of the world's population but only having access to one-third of its usable water resources.

Countries like Singapore have demonstrated a sustainable approach in their management of clean water resources. The city state's highly developed, engineered water systems have provided a reliable supply of clean water for its residents as well as its industries over the years.

However, the impact of the rapid urban growth over our limited water resources is multi-fold: demand for water is on the rise; while more sewage is being produced and treated, more stormwater needs to be managed; and more water pollution needs to be contained.

While each city faces its own unique set of challenges when it comes to tackling sustainability, the bottom line for all is that in order to ensure that we have enough water for the next generation, we need to take a step back and rethink how cities as a whole can better manage this precious resource - be it by reassessing the urban infrastructure or by tapping into new technology.

ADOPTING A 'GREEN-GREY' APPROACH

From water and wastewater treatment plants to pipelines and reservoirs, the urban landscape is rife with grey infrastructure. However, as climate change heralds an increased intensity and frequency of extreme weather events such as heavy rainfall and flooding, these robust, human-engineered systems are crumbling under the increased pressure to manage stormwater.

Singapore, being a small low-lying island state with limited space to store rainwater, is even more vulnerable to the threat of flooding. Moreover, run-off contamination - caused by stormwater picking up pollutants from atmosphere, vehicles and buildings - is a real concern for Singapore as it harvests stormwater on a large scale for its water supply.

A proven way to better manage stormwater is by combining green infrastructure with grey infrastructure. Green infrastructure is a cost-effective and resilient approach to manage the impact of wet weather through the strategic use of networks of natural land, working landscapes and other open spaces.

Singapore has been at the forefront of this approach since 2006, with its Active, Beautiful, Clean Waters (ABC Waters) Programme, an ongoing initiative by its national water agency, PUB. Reservoirs, rivers and canals are integrated with the surrounding environment as part of this strategic initiative, which harnesses the full potential of the country's water bodies and improves quality of life for all.

Increasingly, cities are recognising the effectiveness of the "green-grey" approach. A recent, successful example is China's sponge cities. Facing long-term risks from rising sea levels, the Lingang district in Shanghai replaced concrete pavements with wetlands, green rooftops and rain gardens so that stormwater could be absorbed back into the land, providing an ecologically friendly alternative to traditional flood defences and drainage systems, and enabling water conservation that could be harnessed for reuse by households and industries.

WATER EFFICIENCY IN GREEN BUILDINGS

While climate change has certainly exacerbated the water crisis, one of the major challenges faced by cities today is the inefficient consumption of water.

For cities, buildings account for a significant amount of water and energy consumption, and more residential and commercial buildings are coming up in Singapore. According to the Building and Construction Authority (BCA), total construction demand for both public and private sectors is projected to go up to S$32 billion for 2019. In order to shelter the rising population and boost economic growth, it is important to ensure that we are using water efficiently.

Green buildings have become the new mantra for the sustainable development of cities, including Singapore. There are ongoing efforts to boost the development of eco-friendly buildings that focus on the efficient use of resources such as water and energy. Regulatory enforcement such as Singapore's BCA Green Mark Scheme is setting a benchmark for sustainability efforts by businesses and developers.

However, for buildings to make a difference in their consumption, we need to look beyond just planting trees or incorporating energy efficient office design. We need to also review the entire hardware of buildings to create greater efficiency in all aspects.

For example, pumps control water and the cooling system of a building, operating and using energy year-round. There is also a major opportunity to reduce water losses along the supply chain. However, with pumps usually operating out of sight, few realise the environmental and economic potential of replacing inefficient pumps. By using efficient pumps, buildings can go a long way in meeting sustainability as well as energy and water efficiency standards.

WATER MANAGEMENT WITH DIGITALISATION

An efficient water system goes beyond individual components working in silos, but instead is about how an entire system can work together cohesively to ensure the optimisation of resources. The key to addressing a city's water challenges effectively is interconnectivity between the different parts so as to enable constant feedback and communication, and ensure that resources are used efficiently.

Digitalisation holds vast potential for water and wastewater management by providing capabilities that enable this connectivity. Intelligent technology enables our systems to predict changes in demand, and in turn proactively adjust water pressures to prevent excessive stress on pipes.

Notably, a seemingly simple but serious issue prevailing in many cities has been addressed with the help of digitalisation - water leakage. Intelligent water management solutions have been implemented in several cities to automatically adjust water flow through the use of remote sensors, reducing excessive pressure in the water pipes. This limits water leakages and losses, minimising cost and energy use.

Digitalisation can extend to entire networks across the city, connecting systems, buildings, and public infrastructure. Through the Internet of Things, advanced real-time data collection and sensors, water networks can access information that allows them to operate in a more predictive manner, reducing downtime and avoiding serious business and environmental consequences.

Digitalisation can also be leveraged to develop cities' reactions to extreme climate change events. Water solution providers can generate real-life simulations of a problem and its proposed approach before construction, to test various approaches and optimise them.

Sustainability is not only the most challenging issue but the most urgent need that we face today. To effectively address this, the narrative of urban cities needs to shift from concrete infrastructure to a green approach, one that is married with innovative thinking and modern technologies.

The public and the private sector have a real opportunity to work together and address the water crisis by incorporating green infrastructure, developing green buildings and leveraging digitalisation in water processes. With World Water Day this year reminding us to work towards the collective goal of "Leaving no one behind", we need to accelerate our efforts to ensure a secure and sustainable supply of water for future generations.