The paper reviews the existing tools methods and general literature which deal with the construction of climate change (CC) scenarios and with the assessment of impacts of these scenarios on water resources. It further examines the existing CC predictions specific to Morocco. The paper further describes the publicly available hydrometeorological time series data, which could be used to quantify the future CC scenarios for a river basin in Morocco (Oum er Rbia) and a smaller irrigation scheme within it (Tadla), located in the western part of the country. The data indicates that the impact of future CC on water resources at smaller scales such as smaller river basins, specific water resources and irrigation systems has to date not been properly addressed and, therefore, constitutes a niche for immediate research. This is, especially relevant in areas such as the Mediterranean region, which is predicted to be particularly affected by CC in the future. The preliminary trend analysis of available rainfall data suggests that the possible future CC impacts will decrease the precipitation in parts of the Atlas Mountains, which is the main source of water supply in western Morocco. The more recent data acquisition and the data from national sources in Morocco are necessary to further confirm/reject this hypothesis. The paper also discusses subsequent steps of the study of CC impacts on water resources in Oum er Rbia basin.