Hydrological modelling of water allocation, ecosystem services and poverty alleviation in the Pongola floodplain, South Africa

The Pongola River Ecosystem Services for Poverty Alleviation (PRESPA) project quantified the economic benefits accuring to different livelihood sectors from the water resources of the Pongola floodplain, South Africa. The floodplain carries a diverse economy and ecology which is supported by flood events that once occured naturally but are now regulated by an upstream dam. PRESPA modelled the eco-hydrology which underpins various ecosystem services to determine how this might be managed to alleviate poverty. A model was used to quantify the economic value of the available water, especially the value accruing to the poor. This model linked to three development scenarios to explore trade-offs and outcomes of (1) a status quo, ‘unstructured’ economy; (2) a structured diverse economy; and (3) a structured ‘single sector’ agricultural economy. This model gives decision makers a measure of where water is best used in terms of poverty alleviation and enables them to examine future economic and ecosystem trajectories. In summary, poor households on the floodplain currently have a diversity of income and food sources, making them less vulnerable to economic and climatic shocks, while there is a trend towards intensive agriculture which may deliver higher returns but with greater costs and increased vulnerability.