Road Runoff Harvesting in the Drylands of Sub-Saharan Africa Its Potential for Assisting Smallholder Farmers in Coping with Water Scarcity and Climate Change, Based on Case Studies in Eastern Province, Kenya UNESCO-IHE, 18 June 2013 Ben Kubbinga

Background -Biology, Leiden University -Environment & Resource Management (IVM), VU Amsterdam Working at Min. Economic Affairs (Agency NL) -7th Framework Programme (FP7) / Horizon Competitiveness and Innovation Programme (CIP) -Environmental research & eco-innovation

Thesis at IVM What the potential is for practicing and up-scaling road runoff harvesting in sub- Saharan Africa? 1) What is the performance of existing road runoff harvesting systems in terms of sustainability? 2) What is the (bio)physical potential for up-scaling the use of road runoff harvesting in the drylandsof sub-Saharan Africa?

Contents 1.What is road runoff harvesting (RRH)? 2.Case studies in Kenya 3.Potential of RRH in sub-Saharan Africa

1. What is road runoff harvesting (RRH)? 1. RRH with road side drain: “the collection of runoff from roads and roadsides for productive purposes”

What is road runoff harvesting (RRH)? 2. RRH through a culvert:

Problems with culverts Source: Nissen-Petersen (2006)

Benefits & adoption Benefits -Increased yields -Selling water to neighbours -Raising ducks etc near water -Recharge of wells, dams Adoption -Numbers in SSA mostly unknown (1,000 water pans in Lare Division, Kenya) -‘large potential’

Issues Upstream-downstream -Examples Kitui and Laikipia Districts (Ngigi, 2003:191) “[t]he water laws in most countries of GHA [Greater Horn of Africa] do not provide policy guidelines on runoff sharing as anyone is free to harvest as much runoff as possible without seeking permission from government authorities”

2. Case studies in Kenya

Case study 1: Muindu Musyoka

Case study 2: Mwema Maswili

Conclusions case studies TO DO The case studies (including the four additional sites that were visited) suggest that road runoff harvesting is performing well and can indeed be considered as a welcome, complementary technology for a selected number of smallholder farmers to cope with the unreliable and erratic rains in the drylands of sub-Saharan Africa. It is primarily a simple technology that can easily be adopted by farmers – provided of course that their farm is located in the vicinity of a road. The case studies show that indigenous knowledge is often combined with scientific expertise. Runoff is either used directly for flooding the farm field (runoff farming) or stored for supplemental irrigation. In a second instance, more sophisticated adaptations to runoff harvesting systems can be made, e.g. by adding water reservoirs and water distribution tools. The technology is very flexible and can be adapted to the local conditions. These findings are corroborated by the sporadic information on road runoff harvesting found in literature. Farmers interviewed for this study are overall positive about the impacts of their road runoff systems. Nevertheless, the technical performance, economic viability, environmental friendliness and social acceptance differ per case. Negative environmental impacts have not been recorded. Analysis of adoption factors points at the high establishment and maintenance costs as a critical factor. Comprehensive (technical, economic, environmental and social) benefit-costs analysis of these and other case studies is needed to confirm these outcomes.

3. Potential of RRH in sub-Saharan Africa

Thank you Supervisors: Dr Will Critchley (CIS) Dr Jetske Bouma (IVM) Dr Maimbo Malesu (World Agroforestry Centre/ ICRAF, Nairobi) Alex Oduor (World Agroforestry Centre/ ICRAF, Nairobi) Contact