While Israel is already test-running its flood strategy, it’s not the first time Hamas’s tunnels have been subjected to sabotage by seawater. In 2013, neighboring Egypt began flooding Hamas-controlled tunnels that were allegedly being used to smuggle goods between the country’s Sinai Peninsula and the Gaza Strip. For more than two years, water from the Mediterranean was flushed into the tunnel system, wreaking havoc on Gaza’s environment. Groundwater supplies were quickly polluted with salt brine and, as a result, the dirt became saturated and unstable, causing the ground to collapse and killing numerous people. Once fertile agricultural fields were transformed into salinated pits of mud, and clean drinking water, already in short supply in Gaza, was further degraded.