SA Local government assisted with better planning for extreme events
Virtually all South Africans have in some or other way been impacted by extreme weather events in recent years. On an almost daily basis we see, read about, or experience the negative impacts of floods, droughts, and spells of extreme heat or severe cold. As the projected impacts of climate change become a present reality, we will have to grapple more and more with the adverse impacts of these changes on food security, infrastructure, and a myriad other socio-economic factors.
The risk that climate change poses to water supply and demand is a growing global phenomenon but the impacts are most acutely felt at the local level, where municipal managers are called on to deal with a range of existing complex water management issues. As such, incorporating climate change projections and their implications into municipal management is gaining support in cities around the world.
In response to addressing the local need, the Water Research Commission (WRC), South Africa’s national funding agency dedicated to water-related research and development, funded a study aimed at evaluating the projected impact that climate change is likely to have on water services management for local authorities, with Ekurhuleni Metropolitan Municipality, on the East Rand, selected as the case study.
This was done by modelling future climate change scenarios for South and Southern Africa; identifying the risks associated with the expected consequences of the predicted changes in climate; evaluating the impact on water management using a hydrological model; identifying challenges and limitations of current water management practices as experienced by communities in Ekurhuleni; and assessing the awareness of water sector managers in the municipality of the risks posed by climate change.
The findings have potentially far-reaching implications. Firstly, significant increases in the annual frequency of extreme rainfall events are plausible over the mountainous regions of eastern South Africa – including the Highveld regions of Mpumalanga and Gauteng. Secondly, it is likely that rising temperatures will lead to an increase in extreme rainfall events over the Highveld region, which could result in flash flooding
Dhesigen Naidoo, WRC CEO says, “Many urban poor live in informal settlements within flash flood prone areas, which exacerbates the vulnerability of communities within these regions. Paradoxically, the introduction of infrastructure such as roads, roofs and buildings in flash flood prone areas tends to enhance the impact of this hazard by reducing infiltration and channelling surface run-off. This increases the chance of raging torrents, leading to a higher degree of devastation”.
Another finding pointed to how infiltration drainage facilities can be designed under a changing climate. Increasing infiltration at source and within catchment is central to sustainable urban drainage systems, and infiltration surfaces will need to have the capacity for higher intensities. The study also showed that the potential increase in high-intensity short-duration storms will have a significant flooding impact on stormwater, sewage and drainage infrastructure which, in turn, will affect roads, housing and water resources.
Studies such as these and several others commissioned by the WRC provide valuable recommendations to the municipal water services sector to put in place priority action plans to mitigate against future climate factors. Indeed, this is but one example of how water science can empower municipalities against extreme events.
For more information on this and related studies go to www.wrc.org.za and search our Knowledge Hub to download all reports. WRC reports are freely available to the public.
Contact: Stakeholder Liaison, Hlengiwe Cele