Tiedo obtained his degree in Civil Engineering (coastal engineering) at the Delft University of Technology in 1979. For 38 years until 2017, he worked for the Port of Rotterdam Authority in the field of infrastructure- and water management. He was in the management team for the realisation of the port expansion Maasvlakte 2 as As Strategic Advisor Environmental Management. Since being appointed in 2010, he was Professor Ports and Waterways, Hydraulic Engineering Section, Civil Engineering and Geo-Sciences at Delft University of Technology, and continues as Professor Emeritus mainly doing research projects. He was a project manager for the development and the implementation of the Environmental Ship Index (ESI), an IAPH World Ports Climate Initiative. For PIANC’s Environmental Commission, he has served as chairman of the PIANC/IAPH joint WG 150 on Sustainable Ports and is now co-chairman of WG 174 on Sustainability Reporting for Ports.