CIRAD, HJRBDA and NAERLS undertook a collaborative programme on the Hadejia Valley Irrigation Project to strengthen the agency and the Water Users Associations (WUAs) in their roles and to ensure an efficient transfer of responsibilities from the agency to the farmers. In the scope of the implementation of the Agency/fanner Joint Management concept, stakeholders decided to develop an information system able to provide information for the assessment of the system. The tool aimed to promote the discussion and negotiation between project managers and WUA leaders. The tool is composed of a relational database and a Geographical Information System (GIS). Technically four databases were created to get faster response time. Data entry, storage and analysis are done from a user-friendly interface. Making queries using Mapinfo software automatically generates tables and charts about the irrigation scheme performances. The GIS stores the spatial (Geographical) data. It enables users to represent information like cropping intensities, weed infestation etc, on maps. The development of the information system was iterative and it has been finalized base on field situation and users needs. Training sessions were organized to ensure an efficient transfer to all the collaborating partners and four HVIP staff. The real impacts of the information system are the applications made. Currently agency and farmers use the information system for diagnosis, monitoring and evaluation, discussion and negotiation, and provision of information at policy level. Because of the obvious benefits of the information system the collaborating partners plan to extend the experience to other sites in the country.