Thomas Hartmann is Assistant Professor in the Department of Human Geography and Spatial Planning at Utrecht University, The Netherlands. His research looks at the relationship between land and water, with a focus on river floods and retention. In this research, he combines planning theory, law and property rights, and water governance.Tejo Spit is Professor in the Department of Human Geography and Spatial Planning at Utrecht University, The Netherlands. He specialises in land policy, planning methodology, infrastructure planning, and administrative aspects of spatial planning. He has worked both in the academic world and the more problem-oriented world of municipalities.