Assessing the effectiveness of soakaways as a means of stormwater mitigation in Msida valley

Abstract

Flooding in Malta is a common occurrence during winter. With high intensity rainfall and a highly urbanised watercourse in most valleys, roads become flooded, causing large amounts of damages and inconvenience to the local communities. With the increase in rainfall due to climate change, flooding becomes more of a problem every year. Although there is a system in place already, the National Flood Relief Project, this does not prove to be enough as the roads in the lower watercourse still become flooded with heavy rainfall. In this dissertation, a potential solution is researched to not only mitigate the flooding, but also recharge the aquifers which are over abstracted, leading to an improvement in both quantity and quality of the aquifer. This potential solution is a system of soakaways placed in the upper watercourse of Msida Valley, specifically close to Naxxar, Lija, and Balzan. The research in this dissertation looks at different types of soakaways and their specific niche uses. Potential areas are looked at for soakaway placement and the best area is selected according to guidelines. Lastly a cost analysis is done to determine the economic feasibility of a soakaway system. Research has found that a soakaway system has a place in the Maltese urban fabric and can give many benefits and large return on investment in a short period of time, thus making a soakaway very feasible as a means of stormwater mitigation.