Hydraulic warfare

Hydraulic warfare (HW) is the use of surface water from reservoirs, rivers, canals and other waterbodies as a mass destruction/area denial weapon against the operations of an opposing force during a military conflict. This may involve breaching dams and rerouting watercourses to flood and drown the enemy-held regions of the battlefield, and can be used as a measure of area denial to impede the advance of an attacking ground force, or to reduce the logistic resources and tactical options for fortified defenders. The technique has been used throughout history to create "devastating floods, isolate troops, cut off supply lines, hinder river crossings, and disrupt military timetables".

The English term originated in the 1950s, with the US Army Corps of Engineers.