One of three major water pipelines was struck as Iraqi troops fought back ISIS militants in parts of eastern Mosul.
Officials and witnesses admit a pipeline break has occurred but said ISIS' more sinister agenda has escalated the problem. The group has intentionally cut off water supplies to neighborhoods near the front line, according to Zuhair Hazem al-Jabouri, a Mosul City Council official responsible for supervising the city's water and energy services.
"They (ISIS) cut the electricity to the water stations that feed several neighborhoods where Iraqi troops are advancing," Jabouri said. "They are depriving people of drinking water in eastern Mosul. They want to force people to retreat with them in order to use them as human shields."
The United Nations could not verify the reports but said that the group's policy of indifference has spelled suffering for more than 1 million civilians still inside Mosul.
"There is a clear pattern that we have seen in many of the cities and towns ISIL has occupied: they will use water, food anything to coerce the population. They use people as human shields. They force people into the line of fire," Lise Grande, UN humanitarian coordinator in Iraq, told CNN using an alternative acronym for ISIS.
"Iraqi forces are committed to protecting civilians. They are fighting to rid Mosul of ISIL and trying to protect families at the same time. ISIL forces are intentionally hurting people. One side is trying to protect civilians--the other side isn't," Grande said.
The terror group maintains control of critical water and electricity plants that service thousands of homes in Mosul, Iraq's second-largest city.
"We have information that ISIS shuts and opens water access as they please," Sabah al-Numan, a spokesman for Iraq's counterterror forces, told CNN.
Trapped behind enemy lines
Last week the Hashd al-Shabi or Popular Mobilization Units, or PMUs, announced that Iraqi-led forces had completely surrounded Mosul
The advance created a chokehold on the terror group by cutting off all supply lines to militants.
But for civilians trapped behind enemy lines this development effectively places a siege on the city and leaves them at the mercy of ISIS for the most basic necessities.
"Hundreds of thousands of civilians are living a tragic situation due to the lack of access to water, food, electricity and health care," Izzeddin Aldola, a member of the Iraqi parliament, told CNN.
"I am calling on all international organizations to put more efforts to end the tragedy in Mosul. We need more help and support."
More than 1,200 people, including children as young as 2 months old, have been treated for trauma-related injuries, including from shrapnel, gunfire and mortar rounds, according to the World Health Organization.
Voices from inside Mosul
For about 10 days, Mosul residents have been without clean drinking water. Some communities had pooled together to build makeshift wells when ISIS first took control of the city in 2014. These rudimentary wells are now being re-opened.
A father, who gave the nickname Abu Ahmed for security reasons, told CNN it is a complicated and resource-intensive process to extract water from their wells.
A small power generator and fuel, a rare and expensive commodity, is needed to pull the water via a vacuum.
The water is often soiled, leaving residents exposed to waterborne illnesses.
Each household must wait days for a turn to extricate just a couple of jugs of unclean water, Abu Ahmed said.
"My children don't understand that we are struggling to obtain water and food," he said. "They don't know we are living day by day."
His sister, Om Nayem, said she never expected to use the makeshift well for such a prolonged period. She and her five children have been pinned down in the fighting for weeks.
"We thought we would be the first to be liberated, but we are still waiting. We are all feeling very depressed."
She said she has not ventured outside her home for nearly two months and rarely lets her children past the front door. Playing must be done inside.
Her 16-year-old son seems most affected by the fighting. "He won't sleep, and he is constantly complaining: 'When will we be free?' "
She added, "My hope of all hopes is for security. This is the most important thing for me. We want the world to know we are all really suffering, and we just want a normal life."
Abu Ibrahim, another Mosul father, said if Iraqi forces don't liberate his neighborhood soon he may be forced to retreat to ISIS strongholds in the west of the city.
"I don't want to see my children dying front of me," he told CNN over a crackly cell phone. "I will have no choice if the situation continues like this but to leave my house with my family and head to the west."