Water Management

Supply & Treatment

Sponge Cities

Consumption and Disposal

Supply and Treatment

Supply and treatment refer to the processes of sourcing water—whether from rivers, reservoirs, groundwater, desalination, or recycled sources—and then treating it so it is safe for drinking or reuse. Wastewater is also treated to prevent pollution and allow for potential reuse.

How It Works
Cities diversify their water sources to avoid relying on a single supply. Once collected, water undergoes treatment methods such as membrane filtration, reverse osmosis, or UV disinfection. Wastewater treatment removes harmful substances from sewage and industrial effluents, making it suitable for agricultural or industrial use, and sometimes even for potable water systems.

Importance for Resilience
A secure and varied water supply ensures that households, businesses, and ecosystems can endure droughts, population growth, and environmental changes. Effective treatment preserves public health and reduces pollution, supporting sustainable development and environmental protection.

Examples

• Desalination plants in Australian coastal areas provide additional water during droughts, helping to meet urban demand in dry climates.
• Singapore reclaims wastewater through advanced treatment technologies, producing high-grade drinking water that reduces dependence on external sources.
• The world’s largest fog collector, CloudFisher, in Morocco produces drinking water from fog, demonstrating an innovative approach to water sourcing.

Sponge Cities

Sponge cities are designed to absorb, store, cleanse, and reuse rainfall in an environmentally friendly manner. They help reduce flooding, recharge groundwater, and protect water quality by using features such as bioswales, green roofs, permeable pavements, and strategically placed trees.

How It Works
In a sponge city, trees are planted in flood-prone areas and along streets with specially designed soil cells that filter water before it enters underground storage or detention ponds. These elements mimic natural processes by capturing rainwater, slowing its flow, and allowing it to infiltrate the ground, easing pressure on stormwater systems.

Importance for Resilience
By managing rainwater sustainably, sponge cities reduce the risk of urban floods while enhancing local ecosystems. They also help mitigate the urban heat island effect and maintain a reliable water supply, creating healthier and more resilient urban environments.

Examples

• Many Chinese cities have adopted sponge city solutions by converting paved areas into vegetated spaces that reduce water runoff and improve air quality.
• In some European cities, retrofitted roads and pavements with permeable materials help recharge groundwater, demonstrating how existing urban areas can integrate sponge city principles.

Consumption and Disposal

Consumption and disposal focus on how water is used and discarded in cities. This includes everyday water usage in homes and industries, as well as the management of stormwater and sewage to protect public health and the environment.

How It Works
Efficient consumption involves conservation measures such as fixing leaks, installing low-flow fixtures, and monitoring usage. Disposal methods include proper sewage systems, stormwater control, and recycling initiatives like greywater reuse and rainwater harvesting, which reduce the strain on freshwater sources and minimise pollution.

Importance for Resilience
By reducing water consumption and improving disposal practices, cities can better cope with water shortages and extreme weather events. Lower waste and pollution levels also protect ecosystems and public health, forming a key part of a resilient urban environment.

Examples

• Real-time Leak Detection: In parts of London, water utilities use smart meters and IoT-based sensors to detect leaks promptly, minimising water loss and reducing maintenance costs.
• Greywater Reuse for Irrigation: In drought-prone Australian suburbs, many households have installed greywater systems that treat water from showers or washing machines for use in garden irrigation, cutting demand for mains water.
• Smart Water Monitoring: Pilot programmes in Tokyo provide residents with detailed digital feedback on their daily water consumption, encouraging water-saving behaviours and facilitating faster identification of hidden leaks.