Integrated Water Resources Management (IWRM) has seen mixed progress in Sub-Sahara Africa. Actively promoted by international and donor agencies, IWRM is adopted in various forms by most, if not all, sub-Sahara African countries. However, the advanced framework seems to have difficulty finding its way of integrating governance structure, investment, planning and operations at country and basin level. The greatest challenge lies in the implementation in an environment where knowledge, capacity, infrastructure, and communications are all lacking, all of which drawing critical review of IWRM for water resources development in Africa. Participatory approach, a key principle of IWRM, if often favored by researchers and practitioners. Such approach encourages end users' own initiatives through collaborations with other players. It promotes ownership of water resources development among the beneficiaries which in turn stimulates greater efforts of sustained engagement and improved management. In the absence of equity in knowledge and resources for all the participating stakeholders, participatory approach however often stops at the formality rather than real participatory decision making and implementation. Water as a finite resources in many regions are becoming increasingly scarce as results of population growth and economic development, and often worsen with impacts of climate change. Bottom-up approach focuses on local development and tend to ignore upstream-downstream effects, potentially introducing conflicts should success is secured in one place. This success might alter hydrological regimes of flows to downstream, or be impacted by upstream induced changes in the in-flows. Water resources therefore requires innovative solutions at local level and beyond. This paper explores a small watershed approach to integrated water resources development. The assumption is if coordination of planning and operations are not possible at large scale, e.g., basin scale, then small watersheds where users are responsible for their own development who could easily negotiate with each other have a better chance of adopting integrated approach.
A case study was carried out in Chingale area, Zomba district, Southern Malawi. The study area, with average annual rainfall of 940 mm, is in a small watershed with a drainage area of 188 km2. The watershed is characterized with extensive farm storages (ponds) which are both used for aquaculture, irrigation and aquaculture. A series of studies were carried out including field measurement of river flows, water intake and daily water levels of 2 selected ponds, rainfall and pan evaporation. A household survey was carried out to determine pond ownership, management, cost and benefit. Very high resolution GeoEYE images were used to map house roofs, irrigated areas and ponds. A water balance and allocation model was developed and set up for the catchment to examine the catchment water allocations. Finally, role play games were organized with famers to explore various options of water management and the simulated benefits and tradeoffs.
In total 741 ponds, with an average surface area of 223 m2, were identified with high resolution satellite image. Half of the households own ponds which distribute along with the irrigation belt. While the ponds contribute significantly to household food security, protein intake, and cash income, they are also responsible for almost all of the water withdrawals apart from the amount used for domestic and livestock purpose. Field observations showed that the combined losses of evaporation and seepage/percolation reaches as high as 2590 mm per year, which is 1.7 times of the typical pond water depth (1.5 meter). Modeling results show that at catchment level, water shortage are experienced for various parts of the basin depending on the weather scenarios in dry, normal and wet years. Participatory modeling results using scenarios generated from role playing games however revealed that by building community level water management interventions such as small diversions, optimization of pond water management, and coordinated shift of cropping patterns can reduce pressure on water supply and improve water productivity.
Many parts of Sub-Sahara is still in the cycle of extreme poverty where investment and capacity are prohibitively low for large, formal water infrastructure development. Without necessary infrastructure and meaningful participation, the implementation of IWRM is then constrained in the planning phase on paper. There is both lack of incentive as well as technical know-how for small holder famers to be actively engaged in public large scale water resources management. Water management at farm level is however well adopted by the farmers in Chingale where famers are able to build positive links between water management with their livelihoods. The farm approach is isolated from each other, still representing great risks and vulnerability to climate changes. Following IWRM principle, implementing integrated approach to water resources management at small watershed level could greatly reduce the scale of complexities and lower participatory barriers. It allows for more coordinated water resources management in a manageable environment. Local famers' innovations such as small storage ponds are key to build up assets and knowledge base which in the long run, will contribute to IWRM at lager scale.