J. GOWING1, G. PARKIN2, J. AMEZAGA2, E. OUGHTON1, N. FORSYTHE2
1: Newcastle University, School of Agriculture Food and Rural Development, Agriculture Building, Newcastle upon Tyne, NE1 7RU, UK; firstname.lastname@example.org
2: Newcastle University, School of Civil Engineering and Geosciences, Cassie Building, Newcastle upon Tyne, NE1 7RU, UK
Information on groundwater use for irrigation in sub-Saharan Africa (SSA) is poor and data on its extent is unreliable. This reflects the lack of systematic development and management of the groundwater resource. Large scale use for irrigation (in commercial or public projects) is limited and autonomous development of shallow groundwater by individual farmers is the dominant mode of use. Groundwater is more widely used for rural water supply and in this case public sector and NGO projects have provided deeper boreholes. The absence of systematic development and management is again apparent and trends towards decentralisation and privatisation have led to institutional fragmentation. Groundwater can be seen as an extreme case of a common pool resource management problem. It is easy for an individual user to appropriate the resource simply by accessing the groundwater below his/her land. Indeed, it is the case across much of SSA that groundwater was until recently viewed as 'private water' with entitlement to its use being linked to land ownership. The problem is further complicated by the fact that groundwater is unseen and poorly understood. Improved governance arrangements are needed to support access to groundwater in an inclusive, equitable and sustainable way.
Progress towards achieving good governance of water resources in SSA has been pursued largely through adoption of an IWRM approach. The focus has been on high level policy and the river basin as the management unit, but this has little relevance to groundwater resource management. Groundwater is a widely distributed, but essentially local resource, and governance initiatives must recognise this reality. There is a need for appropriate governance systems to support resource management to achieve sustainable development and to assure equitable access to the resource by poor people. Shallow groundwater resources (<30m depth) are most likely to be used by poor communities because of accessibility, but are particularly vulnerable to over-exploitation and climate risk. Realising the potential of these resources therefore requires a focus on how local communities can assess and manage their own resources which emphasises co-production of knowledge between local communities and scientists/engineers as a means of building local institutional capacity. This requires better (gender disaggregated) understanding of how individuals and communities value groundwater and make local decisions regarding its use. Interventions to promote development of groundwater resources must be based on a participatory approach at local community level.
The methodology has been developed and demonstrated for a case study in Dangila woreda, a local administrative area within the Abay (Blue Nile) catchment near Lake Tana in Ethiopia, but is generally applicable. Dangila woreda comprises 27 village level administrative units; three were selected for the preliminary study on the basis of: (i) access to market and road as proxy of market orientation which is necessary for adoption of groundwater irrigation, (ii) experience in small scale irrigation, (iii) potential of shallow aquifer. Using informal participatory enquiry within these sites, the emphasis was on understanding the role of groundwater in the livelihood system and gaining insights into local knowledge of groundwater. The entry point in each village was to undertake participatory mapping exercises with groups of women and men. After establishing interest in gaining improved understanding, the next step was to promote engagement through establishing participatory monitoring of groundwater levels, rainfall and streamflow.
A local water balance model was developed to provide quantitative understanding of the shallow aquifer at an appropriate scale to address local resource management requirements. This aimed to provide a simplified representation of key water cycle components (e.g. recharge rates, groundwater levels, river flows, groundwater and surface water abstractions, transpiration rates) averaged over appropriate spatial units (local administrative areas).
Results and discussion
Stakeholder consultations together with field hydrogeological assessments have identified the potential for use of shallow groundwater for irrigation in different areas in the woreda. Participatory monitoring of rainfall, groundwater levels, and stream levels by community observers has been shown to provide valuable quantified measurements of these key hydrometric variables on a local scale. These have been used with the hydrogeological interpretations and long-term river discharge data at the larger scale to construct an integrated catchment model using the Shetran modelling system, to help in understanding the relationships between spatial and seasonal patterns of groundwater and surface water resources. From this, simpler water balance models are being developed for local use to support adaptive management.
Building the methodological framework around monitoring by the community enables local scale adaptive management of shallow groundwater resources. The data integration ensures local understanding is at the heart of the assessment methodology, and leads towards development of self-learning capabilities for models which are designed to support local scale adaptive management of shallow groundwater resources.
The pilot study and associated stakeholder consultations in Ethiopia have confirmed that local level participatory management of shallow groundwater is both necessary and feasible provided that appropriate tools and governance arrangements can be devised. Data derived from participatory monitoring has been successfully used to support modelling of the shallow groundwater resource. In the absence of any prior experience with suitable groundwater governance arrangements, it is apparent that the best entry point for local level participatory research will be to build upon other experience with (a) community-based catchment management and (b) existing farmer-managed irrigation (from streamflow diversion).