A local reservoir source can have predetermined monthly inflows, receive runoff from catchments, and demand site and wastewater treatment plant returns, can have storage capability between months and hydropower generation capability. In contrast to river reservoir nodes, they are managed independently of any river system.
"Other" sources have predetermined water quantities available on a monthly basis, but with no storage capability between months (e.g., streams or other unconnected rivers, inter-basin transfers or other imports, and desalination plants.
Local reservoirs and other sources can be linked to any number of demand sites. The user must assign a preference to each link to order withdrawals. Demand site and wastewater treatment plant return flows can be returned to local reservoir sources, but since "other" sources do not have storage capability, WEAP does not capture the water returned to them.