Mitigating the impact of swimming pools on domestic water demand

Abstract

South Africa is a water-scarce country where the sustainable provision of water to its citizens is one of the most significant challenges faced. A recent study in Cape Town, South Africa, investigated the impact of residential swimming pools on household water demand and found that, on average, the presence of a swimming pool increased water demand by 8.85 kℓ/month or 37.36%. Should cities in South Africa wish to develop in a water sensitive manner – where water is treated as a scarce resource with economic value in all its competing uses – it will be vital to understand the impact of swimming pools on residential water demand. Should there be a significant increase in water demand attributable to the presence of a swimming pool on a property, it would highlight the need to consider whether it is acceptable for properties to use municipal water to fill them or top them up – especially in water-scarce/stressed areas. This paper describes a study undertaken in the Liesbeek River catchment, Cape Town, to investigate the impact that swimming pools have on domestic water demand. The results support the contention that properties with swimming pools use significantly more water than those without. This study estimated the additional demand resulting from swimming pools at between 2.2–2.4 kℓ/month or 7–8% of total water demand. The data also indicate that the presence of a swimming pool correlates with a higher indoor demand. The study shows the need to reduce the impact of swimming pools. This could include: pool covers to reduce evaporation, the recycling of backwash water, the use of rainwater to top up swimming pools, water use surcharges and, finally, appropriate regulation and enforcement to prevent the use of municipal water in swimming pools – especially during droughts.