The management of surface and groundwater can be regarded as presenting resource dilemmas. These are situations where multiple users share a common resource pool, and make contested claims about their rights to access the resource, and the best use and distribution of the resource among competing needs. Overshadowed by uncertainties caused by limited data and lack of scientific knowledge, resource dilemmas are challenging to manage, often leading to controversies and disputes about policy issues and outcomes. In the case of surface and groundwater management, the design of collective policies needs to be informed by a holistic understanding of different water uses and outcomes under different water availability and sharing scenarios. In this paper, we present an integrated modelling framework for assessing the combined impacts of changes in climate conditions and water allocation policies on surface and groundwater-dependent economic and ecological systems. We are implementing the framework in the Namoi catchment, Australia. However, the framework can be transferred and adapted for uses, including water planning, in other agricultural catchments.