In this decade of the 21st century, half of the world’s inhabitants live in cities which would transcend into a whopping 60 per cent within the next two decades. This developing world that we are a part of has witnessed the quickest urbanisation, with cities gaining 5 million inhabitants per month on average. But why should these figures perturb us?
With such an explosive population, there comes a rise of unprecedented challenges and a strain on the natural resources of that region is one of them. Amongst them, the elephant in the room is the availability of water.
The substantial role water plays in every living being’s lives is crystal clear, yet we’ve evolved in a shape that hasn’t let the natural resources breathe easy and is now painfully felt when they are not easily accessible. From humans finding their way to water sources to water finding its way to us, urbanisation has massively impacted how humans have altered the hydrological system of cities and their surrounding regions. We scarcely know about where big cities obtain their water or what impact the city infrastructure has on the global hydrologic cycle.
Three significant water-related menaces have and will threaten the long-term viability of human settlements: a scarcity of clean drinking water, sanitation and a spike in water-related disasters such as floods and droughts. These issues have far-reaching implications for human health and well-being, the ecosystem, and economic growth and development.
Presently, cities by their very nature have concentrated the water behests of thousands or millions of people into a limited region, putting additional strain on scarce freshwater sources near the city centre. But how did it all start?
How did urbanization careen towards human needs whilst being ignorant of the ecosystem is of foremost importance to be known to discern the modus operandi of cities towards the water in the immediate future. Earlier, conurbations came together to form a city where dwellings were set up with sewers or septic tanks, wells were drilled, albeit verdure overlooked. These actions led to storm runoff and soil erosion.
Also, the change in water drainage pattern set floods afoot. But the advancements do not stop here. More houses sprang, commercial and industrial buildings annexed, and roads got laid everywhere. Reservoirs have been built to supply water and some stream channels changed to accommodate building construction. Industries started drilling large capacity deep wells for water supply and found the rivers a solution to their waste discharge problem. Now, these changes took a toll on the hydrological cycle.
With more concrete cover, the scope for the underground water table to recharge has reduced resulting in a rapidly decreasing water table. Sinkholes and land subsidence occur as the appalling aftermath. The runoff from the increased pavements is channelled into storm sewers, which then flows into streams. Runoff that used to drain into the ground is now flowing into waterways, causing flooding.
Changing the channel of a stream will result in flooding and erosion along the stream’s banks. More waste is being discharged into faux streams to accommodate such a large amount of water. The past decade has seen a pressing impetus on education and awareness over these issues. Also, bye-laws to limit concrete cover have been imposed nevertheless only a handful of cities around the world have made a difference.
Cities of the future will face a slew of big problems concerning water supply and use. The concern no longer stands only to meet rudimentary needs of water supply, wastewater treatment, and drainage systems, but also towards the ability to protect water’s many indirect benefits of health and biodiversity.
Furthermore, these objectives must be met whilst protecting the environment and maintaining cities’ resilience to natural disasters such as flooding. Continual reforms today on the city’s water infrastructure comprises improved stormwater drainage systems, drilling wells and underground water table recharge pits, irrigating parks and lawns with treated effluent water, rehabilitating lakes, improving the existing water connection system which indicate that we are already taking steps to enter into a tender future.
One of the many ways water may help change the future includes garden cityscapes. Bio-diverse green space parks with artificial groundwater recharge interventions and an inclination to urban food-crop culture as a means of curtailing the urban heat island effect would supplement this vision. This water-sensitive urban design management would help recover the water-cycle system, ensure climate-resilient drainage and flourish urban aquaculture.
The world may also see a rise in cities floating on stilts that would withstand rising sea levels, extreme rainfall and expansion of river floodplains. New buildings in floodplains can be structured to cause their ground-floor level to be submerged, with all below-ground facilities either flood-proofed or elevated in case of floods. The underground services can be integrated into new transport corridors 5-10m above the ground. These techniques would enable recognizing and harnessing the flaws and benefits of floods.
The city water field in future will also focus on how deep geology can go towards housing combined structures built to provide efficient sanitation, water, heating, and cooling services as functions gradually shift underneath the city and engage there as well. Any current underground water and drainage networks become obsolete due to the implementation of building-scale and community-scale recycling models for utility services, but they can be regenerated as transport ducts that supply other services/products through their pipe space.
Water transfer will be combined with energy storage and recovery systems between massive underground storage facilities and above-ground storage facilities. These kinds of cities would enable the elimination of large scale surface water reservoirs and cut the cost required for its construction.
Water-resilient city planning is always tailored. Achieving a safe and livable environment is more important than achieving a water-resilient and climate-proof city. It is imperative to include the living environment and societal values. People are, after all, a member of the urban environment, or “ecopolis.”
Understanding how water as a system of processes can enhance our quality of life can be aided by considering potential communities centred around various approaches to water management.
- McDonald, R.I., Weber, K., Padowski, J., Flörke, M., Schneider, C., Green, P.A., Gleeson, T., Eckman, S., Lehner, B., Balk, D., Boucher, T., Grill, G. and Montgomery, M. (2014). Water on an urban planet: Urbanization and the reach of urban water infrastructure. Global Environmental Change, [online] 27, pp.96–105. Available at: https://www.sciencedirect.com/science/article/pii/S0959378014000880 [Accessed 19 Apr. 2021].
- Rachwal, T., Wharfe:, J., Bricker, S., Sharp, L., Leeks, G., Culshaw, F., Roberts, T., Noble, A., Rogers, C., Butler, D., Acreman, M., Shouler, M. and Zhong, W. (2015). Future Visions for Water and Cities A Thought Piece. [online] . Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/439301/gs-15-27-future-visions-for-water-and-cities-thought-piece.pdf [Accessed 19 Apr. 2021].
- Whitehead, F. (2016). Five of the best water-smart cities in the developing world. The Guardian. [online] 29 Feb. Available at: https://www.theguardian.com/global-development-professionals-network/2016/feb/29/five-of-the-best-water-smart-cities-in-the-developing-world [Accessed 19 Apr. 2021].