A comparative scenario analysis of WSUD measures for stormwater management in Amman, Jordan

Abstract

Jordan is one of the most water-scarce countries in the world. At the same time, it has faced many flash floods due to the topography and rainfall patterns in the region. However, Jordan’s vulnerabilities to these water shocks have been exacerbated due to factors like climate change, rapid urbanization, a huge influx of refugees and the lack of proper management to keep up with these changes. With increased international cooperation, Jordan has committed to achieving various climate goals, however, the implementation of these policies into practice has been a challenge. This Master’s thesis aims to analyse the effects of integrating water-sensitive urban design measures into urban areas in arid and semi-arid climates. This is done by conducting an urban analysis of a catchment in Amman, a developing area called Marj Al Hammam. In this catchment, certain hotspots are identified that are at high risk of flooding, and at the same time present a potential to implement WSUD strategies. Further, three scenarios are envisioned - business as usual, interventions in public spaces and the inclusion of private spaces for stormwater management. While these hotspots vary greatly in their typologies, a common inference was that in the current state, maximum damage would incur due to stormwater runoff. The lack of open public space available according to the current land use plan poses a challenge to integrate WSUD, however, even in the minimal spaces available, its impact is quite apparent in terms of reducing and attenuating stormwater runoff volumes and runoff velocities. Further integrating these measures into private areas, especially rainwater harvesting has a huge impact on the overall system hydrology. Moreover, with strategic storage and treatment, stormwater runoff can be a good source of water supply during the dry periods in Amman. Additionally, these measures come with many ecological and social benefits - improving the microclimate, promoting biodiversity by bringing nature into the city and providing dynamic spaces in the city for people to come together, hence improving the overall quality of stay. The planning and implementation of these measures, however, should be done with stakeholder workshops and public participatory programs. Thus this analysis concludes with recommendations for the further development of the catchment and directs the path to further research on the detailed design of measures, to make Amman a resilient, green, just and inclusive city.