Scenarios of the future are an important tool for supporting sustainability-oriented regional planning. To assist regional planning in two federal states in semi-arid Northeastern Brazil, Ceará and Piauí, we developed integrated qualitative-quantitative scenarios which show potential developments of the agricultural and water resources situation until the year 2025. In these states, regional development is negatively influenced by the high seasonality of rainfall and El-Niño-related drought years. Two reference scenarios, 'Coastal Boom and Cash Crops' and 'Decentralization - Integrated Rural Development' were generated by first creating the storylines and then quantifying the development of the driving forces. Then, an integrated model, which includes modules for simulating water availability, water demand and agricultural production and income, was applied to compute the temporal development of relevant system indicators in each of the 332 municipalities of Ceará and Piauí. These indicators include the fraction of the irrigation water demand than can be satisfied, the volume of water which is stored in the reservoirs at the beginning of the dry season, agricultural productivity and production as well a the internal migration among scenario regions. In addition, the impact of certain policy measures was assessed on the background of both reference scenarios. Reference and intervention scenarios were derived by an interdisciplinary group of scientists and were discussed and refined during policy workshops with planning agencies of Ceará.