TERM-H2O is a dynamic, multi-regional computable general equilibrium model of the Australian economy with agricultural detail adapted to include regional water accounts. It focuses on the effects of inter-regional water trading. Factors of production are mobile between sectors in farm industries. TERM-H2O includes complementarity conditions that impose constraints on the volume of irrigation water traded between regions. The application detailed here is to the Commonwealth government's water buyback scheme against a background of temporary drought. The buyback scheme provides a windfall gain for holders of water rights by raising the price of irrigation water. The scheme may provide a net benefit to irrigation regions while increasing environmental flows.