Hundreds of water and sewage facilities in Gaza have been damaged or destroyed since Israel began its war against Hamas, according to satellite analysis conducted by the BBC's team of fact-checkers.

The damage to the main water supply depot has also caused significant disruption to repairs.

Relief agencies say that the lack of clean water and untreated sewage flow poses a serious threat to health.

This destruction comes despite Israel's duty to protect vital infrastructure under the rules of war unless there is evidence that the sites are being used for military purposes.

The Israeli military told the BBC that Hamas exploits civilian infrastructure for "terrorist purposes."

Clean water has always been a limited resource in Gaza, where the area relies heavily on a network of wells and desalination plants to supply its water.

The BBC analysis concluded that over half of these vital facilities have been damaged or destroyed since Israel launched its war in Gaza following the Hamas attack on October 7.

We also found that four of the six sewage treatment plants, which play a key role in preventing the accumulation of sewage and the spread of diseases, have been damaged or destroyed. Two other desalination plants have been shut down due to a lack of fuel or other supplies, according to one relief agency.
These plants were among more than 600 water and sewage facilities we analyzed, using a list of locations provided by the Coastal Municipalities Water Utility in Gaza.

Dr. Natalie Roberts, the executive director of Médecins Sans Frontières in the UK, said that the destruction of water and sewage facilities has led to "catastrophic health consequences for the population."

She said, "The rates of diseases caused by diarrhea have risen catastrophically."

In very severe cases, this disease can kill young and vulnerable children. According to Médecins Sans Frontières, the rates of Hepatitis A, which is found in contaminated water and poses special dangers to pregnant women, are also high.

Roberts stated, "This kills people."

She noted a noticeable increase in disease rates in Rafah in the south, where many of Gaza's residents have fled, along with the risk of cholera.

Significant damage has occurred to buildings across the Gaza Strip since Hamas attacked Israel on October 7. According to the United Nations, around 69,000 housing units have been destroyed and 290,000 others damaged.

It is unlikely that homes will now receive running water, according to the relief workers we spoke to.

The BBC satellite analysis
To conduct this analysis, we consulted with experts from the United Nations and Human Rights Watch on the best approach.

For each site, we obtained the latest high-resolution satellite images and compared them with an image taken before October 7.

We then marked the facility as destroyed or damaged if it appeared that the nearest structure to the specified coordinates had turned to rubble, partially collapsed, or showed other signs of damage.

The BBC did not distinguish between "destroyed" and "damaged" facilities. This is because, without knowing the exact outline of each facility, we cannot say whether it was partially damaged or completely destroyed.

Water wells typically consist of an underground well and an electric pump, in addition to a small control room above ground. However, since the control room is not always visible or easily identifiable, we had to rely on analyzing the nearest visible buildings when assessing the damage.

Our conclusions
Among the 603 water facilities we analyzed, it appeared that 53 percent of them had been damaged or destroyed since October 7.

We also found that 51 other facilities showed some damage or had solar panels removed, but we could not determine whether the water facility itself was damaged, so they were not included in our analysis.

The latest available satellite images were obtained in March and April, and our analysis has been ongoing since April.

The majority of the sites identified as destroyed or damaged are located in northern Gaza or in the area surrounding the southern city of Khan Younis.

At one sewage facility in Al-Bureij, in the center of the strip, the solar panels that power the station were destroyed, and the sewage treatment tanks appear to have algae growing on the surface.

Not all damage can be seen through satellite images, so our analysis may have missed some affected facilities. Some sites may not also be operating at full capacity due to a lack of fuel.

For example, UNICEF told the BBC that its water desalination plant in Deir al-Balah - one of three major seawater desalination facilities in Gaza - can only operate at 30 percent capacity due to a lack of fuel.

With most of Gaza's residents now displaced from their homes and living in camps, the accumulation of sewage in the streets poses an even greater threat.

Mohammad Attallah, who works at the Palestinian Center for Human Rights, said, "Sewage pumps are not working, and the streets are flooded with water."

Damage to water tanks in Khan Younis
The war has made repairing water facilities challenging for the Gaza Water Authority, but the bombing of a key maintenance depot has made it even more difficult.

The building located in the Mawasi neighborhood sustained severe damage in a missile strike on January 21. Four people were killed, and 20 others were injured, according to the Coastal Municipalities Water Union.

Munther Shablaq, the director general of the Coastal Municipalities Water Utility, told the BBC that this depot, which served as a store for both the Coastal Municipalities Water Utility and UNICEF, contained over 2,000 items used for maintenance, and was the heart of water and sewage services in Gaza. He added that its destruction severely limited the Coastal Municipalities Water Utility's ability to repair and maintain vital facilities like water pipelines.

The Israeli army stated that the depot in Khan Younis was not targeted, but Hamas fighters operating nearby were hit, and "parts of the depot may have suffered damage as a result of the strike."

The BBC provided the Israeli army with a sample of five other damaged or destroyed water sites from our analysis. In one case, the Israeli army denied that an airstrike occurred, and in the other four cases, it stated that Hamas fighters or their sites were the actual targets.

"Hamas stores its weapons and ammunition inside these civilian buildings, and builds a terrorist infrastructure underneath them, from which it carries out its attacks... The Israel Defense Forces identifies and destroys this terrorist infrastructure, which has been discovered, among other places, in the water and near the concerned facilities."

Leila Sadat, the special advisor on crimes against humanity at the International Criminal Court, told the BBC that vital facilities for the survival of civilians should be protected unless a military body has some concrete evidence indicating otherwise.

She stated that to assess the criminality of the warfare, you must consider the "pattern" of those actions.

She said, "You cannot just look at strike after strike... The Israeli army has hit water pipelines, tanks, and infrastructure."

She added, "It would be very difficult to obtain more than half of the water and sewage without doing so intentionally. So this pattern is evidence of a reckless approach to civilian targets or deliberate destruction of them; these were not all mistakes."

In response to our findings, Sarah Elizabeth Dale, an international lawyer specializing in criminal law and human rights, said: "What we are witnessing is essentially a war of siege and complete destruction of Gaza, without any consideration for human life or dignity, or any attempts to comply with international law."