This slide presentation discusses these topics: what is early warning monitoring; existing early warning monitoring networks (EWMNs); developing EWMNs; and, lessons learned. Topics also covered include: components and characteristics of EWM Systems; potential uses of EWMs; general types of monitors; levels of EWMs; benefits of EWMNs; advanced warning systems around the world; Ohio River Valley Water Sanitation Commission case study; Lower Mississippi River case study; Upper Mississippi River Basin case study; Schuylkill River Watershed; Delaware River Watershed; Allegheny and Monongahela Rivers; Susquehanna River Basin; and, Potomac River. Includes 3 references, figures.