December 13, 2023 | Flash Brief

Seawater Flooding of Hamas Terror Tunnels Begun by IDF, U.S. Officials Say

December 13, 2023 | Flash Brief

Seawater Flooding of Hamas Terror Tunnels Begun by IDF, U.S. Officials Say

Latest Developments

Israeli forces in Gaza have begun to flood Hamas’s extensive underground tunnel network with seawater from the Mediterranean, U.S. officials familiar with the operation told The Wall Street Journal on December 12. Israel is reportedly using seven pumps and may need weeks to complete the effort. Israeli officials would not confirm details of the operation. Still, Israel Defense Forces (IDF) Chief of Staff Lt. Gen. Herzi Halevi called it “a good idea” during a media briefing on December 5. Reports estimate that Hamas’s network of subterranean tunnels in Gaza extends 300 miles. So far, Israeli forces say they have discovered 800 tunnels and have destroyed 500 of them.

Expert Analysis

“Nothing would be more fitting than to have Hamas terrorists drown in the terror tunnels that they built to murder Israelis and shield Hamas fighters. Hamas diverted billions of dollars in international aid to build these tunnels instead of spending the money to improve the lives of Gaza civilians.” Mark Dubowitz, FDD CEO

“The Egyptians reportedly flooded Hamas tunnels after Abdel Fattah el-Sisi toppled the Muslim Brotherhood. But the Israelis have never done this before. There may be dangers posed to the foundations of buildings above ground. There also may be dangers to the drinking water drawn from wells and springs. But if this is successful, it could be a way for Israel to tackle one of its thorniest military challenges without firing another shot.” Jonathan Schanzer, FDD Senior Vice President for Research

Hamas Tunnel Network

Hamas uses underground tunnels to shelter its fighters, store weapons, hold hostages, and move undetected. The tunnels frequently run under apartment buildings and hospitals, violating international law. Hamas diverted concrete and other materials meant for civilian projects to build its tunnels, which are outfitted with electricity and telephone lines.

Previous Efforts to Destroy Tunnels

Israeli forces use a variety of techniques to destroy Hamas’s tunnels, including airstrikes, liquid explosives, and robots and drones. Israel has also sealed tunnel entrances with a cement-like substance. Among the various munitions provided to Israel by the United States are 2,000-pound BLU-109 bunker-buster bombs that can be used for tunnels and that other munitions cannot reach.

Over the past decade, Egypt has used seawater, sewage, and gas to destroy smuggling tunnels running between Gaza and the Sinai. The United States pumped tear gas into tunnel complexes built by the Vietcong during the Vietnam War.

10 Things to Know About Hamas Tunnels,” FDD Insight

U.S. Continues to Arm Israel as IDF Discovers Large Hamas Weapons Depot,” FDD Flash Brief

10 Things to Know About Hamas,” FDD Insight


Israel Israel at War Palestinian Politics