Rainwater and greywater harvesting for urban food security in La Soukra, Tunisia

This paper presents the findings of an integrated household water treatment and reuse system for agriculture in La Soukra, Tunisia. The researchers found that the system has an internal rate of return of 17% and a net present value range from USD 26,000 (at a 5% discount rate) to USD 11,000 (for a 10% discount rate). Benefits included more water for irrigation, reduced costs to service providers, increased agricultural production from greenhouses and expanded agricultural options. These results suggest that investments in rainwater harvesting and greywater treatment at the farm level can increase the financial feasibility of peri-urban farms, which are often faced with pressure from urban growth. The systems can also help build household resilience to broader environmental change by lowering the exposure of farmers to burdens associated with infrequent access to water and poor-quality soil.