Combining scenario workshops with modeling to assess future irrigation water demands

•Scenario workshops are used to construct visions of agriculture in 2030 in Southern France case study.•Irrigation water requirements are estimated for these scenarios.•Uncertainty on future demand for irrigation is discussed.

We discuss methodological issues related to the development of long term future agricultural water demand scenarios. We present the results of original research which combines the use of scenario workshops with quantitative crop water requirement modeling approaches. Using a Southern France case study, we describe four scenarios, debated with farmers and stakeholders during workshops and evaluated in terms of total water demand. Results suggest that socio-economic evolution could lead to a 40% increase of irrigation water demand. From a methodological perspective, the research highlights the mutual benefits for both policy makers and scientists of involving stakeholders in the development of scenarios, using both qualitative storylines and quantitative modeling tools.