Dr.  Tyagi  has been associated with  a number of water related programmes launched by international agencies like ICID, IPTRID and FAO. He was nominated to working groups of ICID on ‘Irrigation System Performance’ in 1995, Special Sub Group on Saline Water Use in 1996, Organizing Committee of 6th Drainage Workshop in 1999-2000. He was invited by FAO for Expert Consultations on several occasions and was also requested to prepare special reports/state of the art papers etc. He was the Indian Team Leader of the European Union supported programme on ‘Policies for Water Saving in Yellow River Basin: A DSS Applied to Ningxia and Shandong’ in China in which four institute from Europe, two from China and CSSRI from India participated. The programme operated for five years from 1999-2004. He worked as the Indian Coordinator of the DFID supported project and was also responsible for organizing workshop for the Aral Sea Basin Countries to develop collaborative programme on salinity management (1999). He was the Indian Coordinator of IWMI’s programme on’ Farmers Managed Irrigation System” in India (2000-2003) at CSSRI. As a consultant, he assisted in framing the core structure and programme for   National Salinity Research Centre, Yazd (Iran).