The Global Water Partnership South Asia (GWP SAS) was established in December 2002 in Pakistan, building on the Water Vision 2025 and Framework for Action developed by the South Asia Technical Advisory Committee (SASTAC, 1998–2003). Since then, GWP SAS has been actively engaged in addressing key regional challenges in water and related sectors. 

Representing Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka, GWP SAS connects these countries through their respective Country Water Partnerships (CWPs). While each CWP operates autonomously, they are united by a shared mission: support South Asian countries in the financing, governance, and management of water resources for sustainable, climate-resilient, and equitable development.