Israeli soldiers walk down the tunnel entrance below Al-Shifa Hospital in Gaza City on November 22. Photo: Reuters

The Israeli army plans to pump seawater into the Hamas tunnel system in Gaza, but this plan has many potential humanitarian risks.

On December 3, the Israel Defense Forces (IDF) announced that they had discovered 800 paths leading down to the Hamas tunnel system since launching the campaign in the Gaza Strip. Israeli engineers disabled 500 tunnel doors by detonating or sealing them and destroyed many kilometers of the armed group’s main tunnel route.

However, this is only a small part of the “matrix” of tunnels that Hamas has painstakingly built over the past 30 years, estimated to have a total length of more than 500 km. According to Zoran Kusovac, a veteran analyst for Al Jazeera, Hamas has opened tens of thousands of tunnel entrances in the Gaza Strip. Each tunnel usually has many entrances, so unless the IDF destroys all the tunnel doors, Hamas forces can still operate normally underground.

Instead of searching and destroying each tunnel, the Israeli military is considering the option of pumping seawater from the Mediterranean into Hamas’ network of tunnels to destroy them, the Wall Street Journal on December 4 quoted officials as saying. America is anonymous.

According to these officials, the IDF has installed at least five large pumps near Al-Shati refugee camp since mid-last month. These pumps pump thousands of cubic meters of seawater every hour to flood the entire tunnel system in the Gaza Strip.

Israel informed the US about its plan to pump water to submerge the Hamas tunnels early last month but has not yet decided whether to proceed with this plan or not.

“Israel’s plan has caused mixed reactions in US politics regarding its feasibility and environmental impact when compared to the military value it brings,” these officials said.

Some US officials expressed concern about the plan, while others said Washington supported Tel Aviv, adding that “there is not necessarily any US opposition to this plan.”

President Joe Biden’s administration has not responded to the information. An IDF official declined to comment but emphasized that the force is “attempting to destroy Hamas’s infrastructure in many ways, using many different technological and military tools.”

A source familiar with Israel’s battle plans said the pumping process took place over several weeks, giving Hamas members and hostages enough time to leave the tunnels before they were flooded.

“We are not sure how successful the plan will be because no one knows the details of the tunnel system and surrounding ground,” the source said. “None of us have ever been in the tunnel, so we can’t predict how the water will recede.”

It is unclear whether the Israeli military plans to pump water into the tunnels before or after all hostages in the Gaza Strip are released. Hamas is estimated to hold still about 104 hostages, most of whom are believed to be held in underground tunnels.

Another concern is the impact of this plan on the living environment in the Gaza Strip, especially water resources. Most people in the territory currently do not have access to clean water, in the context that many water filtration plants here have to stop operating due to fighting. Of the three water pipelines from Israel into the Gaza Strip, one has been closed, and the remaining two have sharply reduced capacity.

IDF tanks move near the Israel - Gaza Strip border on December 4.  Photo: Reuters

IDF tanks moved near the Israel – Gaza Strip border on December 4. Photo: Reuters

The United Nations said that, on average, each person in Gaza receives about three liters of water a day, equal to one-fifth of the minimum amount of drinking water according to world standards. A former US official said that the water and sanitation systems in the Gaza Strip were damaged and heavily polluted due to the conflict and need help from the international community to rebuild after the fighting ends.

According to Wim Zwijnenburg, a researcher on the impact of war on the environment at the non-governmental organization PAX, based in the Netherlands, pumping seawater to flood the tunnel can cause toxic substances from weapons and fuel to be released. The rockets that Hamas stored in the tunnel seeped into the ground, polluting the groundwater in the Gaza Strip, which is becoming saline due to the effects of rising sea levels.

“Even if the Hamas tunnel system has been damaged by more than 30% due to fighting, the Israeli army still needs to pump about another million cubic meters of seawater to neutralize the rest,” Zwijnenburg said.

Meanwhile, Jon Alterman, vice president of the US-based Center for Strategic and International Studies (CSIS), said it is difficult to fully predict the impact of pumping seawater into the tunnels because clearly see the permeability level of the tunnel system.

“It is not easy to determine how Israel’s plan will affect water and sanitation infrastructure in the Gaza Strip, as well as groundwater reserves and the stability of nearby structures,” Alterman said.

In 2015, the Egyptian army pumped seawater to flood a tunnel operated by smuggling groups under the Rafah border crossing on the border with the Gaza Strip, but this measure affected the crops of farmers cultivating nearby, causing many people to complain.

A former US official admitted that if Israel carries out this plan, Washington will be pushed into a “difficult situation,” which could cause the Biden administration to receive condemnation from the international community in the context of Tel Aviv. It is being criticized regarding the large casualties in the Gaza Strip during the operation.

Health authorities in the Gaza Strip said at least 15,800 people were killed and more than 42,000 injured by Israeli attacks on the strip following a Hamas raid on October 7.

Mick Mulroy, a former officer of the US Central Intelligence Agency (CIA), said that pumping water to flood the tunnel is an effective tactic to force Hamas gunmen to leave underground instead of choosing risky methods. The risk is to send infantry inside to destroy resistance pockets.

“However, if groundwater becomes salty as a result of this method, a humanitarian crisis could erupt in the Gaza Strip,” Mulroy said.