The international watershed codification system for the Indian River basin is proposed for the better water resource management & monitoring, river basin planning, innovative research in hydrology, and sustainable water resource development. Based on natural system, the sub-continent largest transboundary to mini-watershed boundaries have been delineated from SRTM, ASTER, & CARTOSAT DEM data. The nine-digit watershed codification is proposed for the Indian River basins, recognizing each hydrologic unit with unique international code that provides a single stand to synergize all the development programs related to river basin planning, and natural/water resource management, and avoiding doubling of interventions of various departments & ministries.