We evaluate alternatives for the management of water for agriculture under climate change in six representative basins of Southern Europe: Duero-Douro, Ebro, Guadalquivir, Po, Maritsa-Evros and Struma. Management objective is maximizing water availability, understood as the maximum demand that can be satisfied with a given reliability. We focus on water availability for agriculture. For simplification we are assuming only two types of demands: urban and irrigation. Water is first allocated to urban demands following the established priority and the remaining resources are allocated to agriculture. If water availability is not enough to satisfy all irrigation demands, management measures are applied with the goal of achieving a balance between resources and demands. We present an analysis of three possible management measures to face water scarcity in the long term scenario: increasing reservoir storage, improving efficiency of urban water use and modifying water allocation to environmental flows. These management measures are globally evaluated for the selected basins in three representative climate scenarios, comparing their possible range and effectiveness. While in some basins, like Ebro or Struma, measures can significantly increase water availability and compensate for a fraction of water scarcity due to climate change, in other basins, like Guadalquivir, water availability cannot be enhanced with management measures and irrigation water use will have to be reduced.