Population growth, climate variability and competition between different sectors, have put severe pressure on high‐quality freshwater sources. These challenges exact the necessity to explore alternative water sources to meet the demand for freshwater. Now it is key to know how to sustainably incorporate the alternative water supply sources (i.e. reclaimed wastewater, agricultural drainage water, stormwater harvesting, desalinated water, etc.) into the water supply systems at the watershed scale. Effective planning tools, modeling techniques and policy considerations are all needed for sustainable management of these alternative sources. The proposed session will provide an opportunity for scientists, engineers, and practitioners from many disciplines to showcase their experience in planning, incorporating, and managing alternative water sources at watershed scale from theory to practice.