Decentralized water demand management technologies for urban water management

Let's get radical

In a city like Victoria, BC, radical water demand management would look like transitioning from conventional sewerage to a combination of on-site sanitation, greywater management, and rainwater harvesting. There has been an increase in environmental and social pressures, such as an increased frequency and severity of climate changes and droughts, “limited new unpolluted freshwater resources, population increase and shifts, [and] changes in lifestyles” (Baki et al., 2018; Vallès-Casas et al., 2017). These pressures make it clear that conventional water management systems are short-sighted. Conventional water management infrastructure was built assuming long-term abundance and consistency of water resources, assumptions that are now acknowledged to be patently untrue (Kirk, 2018). The potential for a combination of decentralized household-level water management techniques to improve urban water management is significant (Makropoulos & Butler, 2010). Rather than continuing with the status quo of wasteful inefficiencies, there is an opportunity to invest in water management infrastructure at the household level that minimizes water required from the central supply and the amount of wastewater discharged into the central system (Makropoulos & Butler, 2010).

An improvement of city-level management and infrastructure of urban water resources is critical. The city of Cape Town, South Africa provides a real-life example of the potential future risks faced by thousands of cities in the next 5 to 25 years. Domestic consumption of water demand represents almost two-thirds of Cape Town’s water demand (Mukheibir & Ziervogel, 2007). The city of Cape Town has strongly encouraged water conservation measures like waterless toilets and greywater reuse, but the city as a whole remains tied to outdated centralized wastewater treatment system that faces an increased frequency of blockages as a result of a decreased water flow through the system (Kahn & Phakathi, 2018). In other words, the city can only pursue so much water conservation before its infrastructure starts to fail. Before cities invest in developing additional sources of water, it is imperative to establish effect water demand-side management such that a city’s infrastructure facilitates rather than competes with efficient resource management.

The potential for decentralized household-level water management techniques depends on an understanding of the city’s water management system as a whole, household-level behavior and preferences, as well as the overall socioeconomic context (Baki et al., 2018). Greywater reuse has been growing popularity in popularity at the household level (Andersson et al., n.d.). In order to understand how to make greywater reuse and other decentralized water demand management technologies more effective, it is necessary to understand what factors affect households’ water consumption as well as characteristics that may affect their willingness to adopt a new technology (Vallès-Casas et al., 2017). The adoption of decentralized water demand management technologies can be further encouraged via the use of policy tools and aggressive water pricing, while also considering how these tools can ensure equitable access to an overall declining supply and quality water (Baki et al., 2018).


Andersson, K., Rosemarin, A., & Lamizana, B. (n.d.). Sanitation, Wastewater Management and Sustainability: From waste disposal to resource recovery.

Baki, S., Rozos, E., & Makropoulos, C. (2018). Designing water demand management schemes using a socio-technical modelling approach. Science of the Total Environment, 622623, 1590–1602.

Kahn, T., & Phakathi, B. (2018, January 25). Sewers will keep functioning, Cape Town assures residents. Times Live. Retrieved from

Kirk, A. (2018, August 8). Cities in the face of drought. The Telegraph. Retrieved from

Makropoulos, C. K., & Butler, D. (2010). Distributed water infrastructure for sustainable communities. Water Resources Management, 24(11), 2795–2816.

Mukheibir, P., & Ziervogel, G. (2007). Developing a Municipal Adaptation Plan (MAP) for climate change: The city of Cape Town. Environment and Urbanization, 19(1), 143–158.

Vallès-Casas, M., March, H., & Saurí, D. (2017). Examining the reduction in potable water consumption by households in Catalonia (Spain): Structural and contingent factors. Applied Geography, 87, 234–244.