Benefits of rainwater harvesting for gardening and implications for future policy in Namibia

Abstract

Rainwater harvesting to irrigate small-scale gardens enhances food self-sufficiency to overcome rural poverty. So far rainwater harvesting is not encouraged by the Namibian National Water Supply and Sanitation Policy nor supported financially by the Namibian government. This study proposes two rainwater harvesting facilities to irrigate gardens; one collects rain from household roofs with tank storage, the second collects rain on a pond roof with pond storage. The aim of this paper is to assess the benefits of rainwater harvesting-based gardening and to propose policy and financing implications for the Namibian government. We investigate the benefits of rainwater harvesting through a literature review, a cost-benefit analysis, monitoring of project pilot plants and a comparison with the existing irrigation and drinking water infrastructure. The results indicate that rainwater harvesting offers numerous benefits in technological, economic, environmental and social terms. The facilities have a positive net present value under favourable circumstances. However, material investment costs pose a financing problem. We recommend that government fund the rainwater harvesting infrastructure and finance privately garden and operation and maintenance costs. Integrating these aspects into a national rainwater harvesting policy would create the conditions to achieve the benefits of an up-scale of rainwater harvesting based gardening in Namibia.

How the Social-Ecological Systems Concept Can Guide Transdisciplinary Research and Implementation: Addressing Water Challenges in Central Northern Namibia

“…As part of the 'technological development', different rainwater and floodwater pilot plants were established to investigate whether the technologies were feasible options for improving livelihoods in Namibia on the basis of scientifically derived evidence. Rainwater harvesting plants have been in operation at Epyeshona in the peri-urban surroundings of the town of Oshakati since 2010 [32,56,57].…”

“…Such analyses together with continuous communication and exchange provided strong back-up for the incorporation of the project activities into current regional and national planning activities. In the long term, it supports the political and legal safeguarding of users and could foster future dissemination processes [56]. By strengthening local food production, the project contributed to blueprints such as Namibia's Vision 2030 [29] and Millennium Development Goals No.…”

“…For optimisation and evaluation, a comprehensive socio-technical monitoring programme was developed with the communities at every project site. For instance, cost-benefit analyses at household level identified 'ferro-cement' to be the most cost-efficient material for tank construction [56]. Furthermore, empirical studies were crucial in addressing questions raised by stakeholders or institutions about how to adapt implementation in future.…”

“…The main achievements were the successful implementation of RFWH, the adoption of responsibilities as part of the ownership process, and the establishment of everyday use of this technology. Appropriate storage volumes allowed small-scale gardening throughout the year, enriched and diversified the farmers' diet, and allowed income generation by selling the harvest at nearby markets [56]. Jobs in plant construction and gardening activities could be created and a stimulus for the regional economy generated [56].…”

“…Appropriate storage volumes allowed small-scale gardening throughout the year, enriched and diversified the farmers' diet, and allowed income generation by selling the harvest at nearby markets [56]. Jobs in plant construction and gardening activities could be created and a stimulus for the regional economy generated [56]. Reduced dependence on food imports from South Africa was also expected.…”