Environmental Flow in the Context of Small Reservoirs in West Africa Yongxuan Gao 21 March 2009

Session Rainfall in West Africa Unevenly distributed spatially and temporally Often comes in the form of thunderstorm Droughts and flash floods are frequent

Session Small Reservoirs Large inter-year variations in the agriculture production potential, leading to insecure livelihoods Many have been built in rural area for livestock watering, small-scale irrigation, fishing and construction There are 160 small reservoirs in the Upper East Region of Ghana, 1400 in Burkina Faso and 250 in Northern Cote d’Ivoire (

Session Small Reservoirs (2) Developments are spontaneous and many of them have deteriorated over time due to poor maintenance Construction and rehabilitation are funded by different agencies, at different times, with little coordinative effort among the agencies to facilitate a regional optimization of investments

Session Small Reservoirs as a System Store a significant amount of water and influence downstream flows But have rarely been considered as a system Little consideration has been given to their collective impact on the watershed and livelihoods in the long term Impact is difficult to quantify given the diffuse nature of the small reservoirs

Session Environmental Flow Study is needed to investigate the effect of the small reservoirs as a system on the river Appropriate planning strategies should be formulated if any negative finding is found

Session Description of the Project A case study conducted in the Upper East Region of Ghana Hydrological, ecological and socio-economic implications of small reservoirs Interview with the farmers Funded by IWMI

Session Macroinvertebrate Ecological indicator Preliminary result: little difference between the sites upstream and downstream of the small reservoirs –No impact –Not enough samples to reach a conclusion Need to do more analysis

Session Can innovative engineering and water management techniques to restore environmental flows strike the right balance between the human needs for which river systems were initially developed and ecological needs?

Session Engineering can only take us a little further, but not too far In the long run –Holistic approach in reservoir operation –formulation and implementation of environmental flow policy and regulation No such policy exists for many rivers or watersheds Even there is, very vague or hard to implement

Session What has been recent experience in striking this balance and what new scientific, technological, and policy approaches are on the horizon?

Session Ecological value should be the or part of the objective in reservoir operation or optimization model Need to develop effective hydrological indices A dataset of streamflow, before and after alteration, along with associated ecological impacts on selected fauna and flora –However, not much data exists pre- and post-dam construction –Most studies focus on fish or insect collections made immediately upstream and downstream from the dam, and even this kind of data is not abundant

Session Ecosurplus and ecodeficit High correlation with the IHA (Indicator of Hydrological Alteration)

Session How can the views and concerns of all stakeholders be considered and effectively integrated into the design of such projects?

Session River is a legitimate stakeholder! Involve stakeholders from the planning stage of the project Integration should begin on the village (community) level Information about the project should be make readily available to the stakeholders, especially if the project is in rural area of a developing country

Session The role of traditional leadership is very important in water management Traditional practices, which have evolved with the biophysical and cultural settings in the society, are generally sustainable Water governance must take traditional values into account