Middle East Eye: What is the impact of flooding Gaza’s tunnels with seawater?  

The Israeli army has begun pumping seawater into tunnels used by Hamas in Gaza, as the Middle East Eye reported that researchers specializing in water, diplomacy and conflict have said that the floods will have devastating environmental effects, including contamination of Gaza’s already devastated water supplies and damage to its crops.

The effects may also amount to a violation of International humanitarian law, according to one expert.

Israel hasn’t officially provided any details about the flood plan, considering the information confidential.

According to Juliane Schillinger, a researcher at the University of Twente in the Netherlands, “While the general scope and magnitude of the impact is unclear, we can reasonably expect that at least some seawater will… It seeps into the soil from tunnels, especially in areas where tunnels have previously been damaged”.

She added that the leakage will lead to local contamination of soil and groundwater with seawater.

She continued, saying, “It’s important to keep in mind that we are not just talking here about water with a high percentage of salinity; The seawater along the Mediterranean coast is also polluted with untreated sewage, which is constantly discharged into the Mediterranean from Gaza’s dysfunctional sewage system”.

According to the Middle East Eye, Gaza’s coastal aquifer, the only water source in the besieged Strip, is already polluted due to excessive water pumping and sewage; Water is provided intermittently to Palestinians in the area through pumps controlled by Israel, with the beginning of the current conflict in early October, Israel completely stopped the pumps for several days.

In fact, about 96% of domestic water in Gaza is polluted and unfit for human consumption.

As a result, most Palestinians in the Strip rely on unregulated private water tankers and unlicensed desalination plants.

As for Michael Mason, a professor of environmental geography at the London School of Economics, “The war has already increased the degradation of the aquifer, as a result of damage to wastewater infrastructure and the leakage of heavy metals from the indiscriminate use of munitions”.

Juliane Schillinger, pointed out that if Hamas stores toxic materials in the tunnels, the pollution could be exacerbated by the infiltration of these materials into the soil and groundwater.

Seawater flooding would cause long-term damage to Gaza’s agriculture as well, which has long been destroyed by Israeli actions.

In addition to the environmental impact, the flood plan also raised concerns about the safety of Israeli prisoners captured during the Hamas attacks on southern Israel on October 7, who may be held in the tunnels.

Finally, this won’t be the first time the tunnels have been filled in an attempt to weaken Hamas, as Egypt flooded the networks with sewage in 2013 and seawater two years later.

Egypt did this as part of its efforts to prevent the alleged smuggling of weapons, resources, and fighters between southern Gaza and the Sinai Peninsula.

A seawater flood eight years ago submerged civilian homes and shops in Gaza, as well as damaging water supplies and agricultural land.

Israel is likely to argue that flooding the tunnels is proportionate as a military objective under international law, due to Palestinian fighters’ use of the nets, however, “actions that cause long-term damage to the environment are considered illegal,” according to professor Michael Mason.