from the WaterChannel:
Question: How can dusty roads provide water?
Answer: By harvesting and storing rainwater when it falls on them.
A 30 mm rainfall over a 1-kilometre stretch of road can produce up to 100,000 litres of water. This number points to a huge potential. And not one that has not been adequately tapped (around 7 billion USD are spent on road construction in sub-Saharan Africa alone).
This is not a hypothetical proposition. In Tigray (northern Ethiopia) communities, government agencies and entrepreneurs have come together and implemented road water harvesting mechanisms in 30 districts. Initial impact assessment results show that soil moisture levels along these roads has increased, shallow groundwater levels have risen, and gullying has been controlled.
Much of this was triggered by the research program ‘Optimising Road Development for Groundwater Recharge and Retention,’ carried out by Mekelle University (Ethiopia), MetaMeta (The Netherlands) and Institute of Development Studies (UK), and the Tigray Bureau if Agriculture and Rural Development. The program was supported by UK’s National Environment Research Council and Economic and Social Research Council.
The blog post ‘Roads for Water: Looking for a Better Match’ gives an account of what goes into successful implementation of road development for water security. And how the gains made in Tigray can be multiplied and upscaled to national and regional levels.
Do you know of success stories/ failed attempts at harvesting water from roads? Please share them with us by commenting on the blog post, or by emailing us at firstname.lastname@example.org