The Possibilities of Capturing Rainwater and Reducing the Impact of Floods: A Proposal for the City of Beira, Mozambique

Abstract

Modern societies face various challenges, including climate change, rapid urbanization, and sometimes inadequate urban planning policies. In recent years, extreme weather events have received increasing attention for their impacts on cities, humans, and ecosystems worldwide, particularly on coastal towns in Mozambique, such as cyclones, floods, water pollution, and water scarcity, demonstrating their vulnerability to climate change. Cities must adapt to cope with the pressure on their water resources, and it is essential to ensure that communities have access to safe, reliable, and affordable water. A viable way to promote this resilience and simultaneously reduce costs in domestic budgets is to use rainwater to meet daily needs where water quality parameters are not required for consumption. According to the results of this study, it is possible to significantly reduce potable water use from the municipal water supply network by harvesting rainwater, up to 40% when the use does not require potable water at all, proactively protecting this vital resource. In addition to these direct benefits, the large-scale deployment of rainwater harvesting (RWH) systems in densely urbanized areas can also provide indirect benefits, such as reducing peak flow volumes in stormwater drainage systems and potentially reducing the frequency of urban floods. These benefits result from the reduction in the volume and duration of water sent to the drainage network, which can help to improve the overall resilience of communities in the face of climate change and other challenges.

Simulating the effect of rainwater harvesting on flood mitigation: the case of Asunción, Paraguay

“…Using the scenario of past floods in Ibadan, Nigeria, Wahab and Ojolowo [6] studied the impact that RWHS would have had if they had been installed, concluding that the floods would have been prevented. Santos et al [7] studied the possibility of RWH in Beira, Mozambique, and mentions its potential for reducing the impact of floods. Soh et al [8] developed a methodology for the optimal design of a unit with multiple interconnected tanks, intended as a RWHS and flood abatement system for a large residential area.…”

Influence of Vegetation in The Flood Drainage Ditch

“…Without flood drainage ditches, water would flow indiscriminately, leading to severe flooding and erosion. They play a crucial role in preventing floods by providing a way for water to move away from areas where it can cause damage [1,2].…”