Flood Management in the Lower Incomati River Basin, Mozambique: Two Alternatives

Abstract

The aim of this paper is to compare two views of flood management and thus add to the present thinking of living with floods as opposed to the traditional approach of flood control. The traditional pathway has widely been adopted in developed countries and aims to control floodwaters by means of dams and dikes. The alternative pathway tends towards a policy whereby society lives with the floods by being prepared and having the right damage reduction measures in place. In this paper two pathways are tentatively compared for the Lower Incomati Basin, Mozambique. In the design cultural theory is considered, as is how the design of each path may look according to different management perspectives. The Lower Incomati Basin provides an interesting case study as it is in a relatively undeveloped state. Hence, it is an ideal area for conducting research into the application of alternative flood management strategies. The preliminary results suggest that both pathways are feasible. However, considering recent hydrological extremes such as the 2000 floods, the resilient pathway may ultimately be a more appealing flood management strategy.(KEY TERMS water management; social and political; flood risk; cultural theory; flood management scenarios; Incomati River; Mozambique.)

Livelihood change, farming, and managing flood risk in the Lerma Valley, Mexico

“…In regions where investments in flood control are not yet significant, and where policies for environmental protection are under development, there may be more opportunities to implement a ''living with floods'' approach. Van Ogtrop et al (2005), for example, argue that in rural Mozambique, the population's prior experience with flood hazards might make such an approach viable under specific conditions: the public's active engagement with the process of risk management, the availability of a reliable and accessible early warning service, the implementation of innovations in residential architecture, and the creation of safe havens from floodwaters to minimize losses associated with increased exposure to flooding. In most cases, such an approach implies a need for a deeper understanding of what flood losses mean to particular populations through participatory planning (Johnson et al 2007).…”

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“…The dikes protected against most high flow events, but by constricting flow area in the floodplains the dikes also cause increased flood levels in the river, exacerbating flood risk at locations elsewhere and increasing potential damage due to violent flood flows in case of dike breaches, but this trade-off is not considered (as, for example, proposed in Van Ogtrop, Hoekstra, & van der Meulen, 2005). Dike breaches with devastating impacts occurred in 1978 in the lower Zambezi and in 1977in the Limpopo (CS, 2013 Construction and maintenance of dikes in Mozambique was, and in many regions remains, poor.…”

The Hydrodynamics of the Incomati Estuary – An Alternative Approach to Estimate the Minimum Environmental Flow

“…It suffers water shortages as a result of flow restriction in the upper riparian countries during the dry season, and floods as a result of water releases in the upper riparian countries during the rainy season. The most recent devastating floods occurred in the year 2000, and had severe impacts on agriculture and infrastructures, as well as causing a significant loss of lives (van Ogtrop et al 2005;Carmo Vaz and Lopes Pereira 2000). Figure 3 presents the average monthly river discharge over the period 1953-1979. Variations in discharges from year to year are significant, with a coefficient of variation of around 50-65% (Smithers et al 2001).…”