The UN is concerned about waterborne diseases because part of the water supply to the regime capital has been cut off. A UN spokesman said sabotaging civilian water supplies is a war crime.
A Syrian regime provincial governor on Wednesday said the regime and opposition groups had agreed on a plan to repair damage to a spring in the Wadi Barada area that supplies water to Damascus.
But that claim was disputed by Abu Mohammed Bardawi, Director of the Media Centre for the Wadi Barada local council.
"We deny any reconciliation deal by any of the responsible parties here and no technical teams have entered the area at the time of the writing of this statement. Regime forces did present a deal which was discussed by the revolutionaries and the residents of the area, but no agreement has been reached as of yet," Bardawi told TRT World.
The UN has said the infrastructure of the spring was deliberately targeted, without stating who was responsible. The spring was knocked out of service in late December, leaving 4 million people in Damascus and surrounding areas without safe drinking water.
TRT World's Abubakr al Shamahi is following the developments from Gaziantep, near the Turkey-Syria border.
Rebels and activists have said regime bombardment damaged the spring. The regime said rebel groups polluted the spring with diesel fuel, forcing it to cut supplies.
Clashes and airstrikes in Wadi Barada have threatened a nationwide ceasefire brokered by Russia and Turkey nearly two weeks ago to pave the way for peace talks.
The regime forces and allied fighters from Iran-backed Hezbollah launched an offensive in late December to capture Wadi Barada.
Rebels in Wadi Barada have allowed regime engineers to maintain and operate the valley's pumping station, the capital's main water source, since they took control of the area in 2012.
Fighters have, however, cut water supplies several times in the past to put pressure on the army not to overrun the area.
The United Nations estimates 45,000 people live in the Wadi Barada area, and thinks at least 7,000 people have been displaced from the area in recent fighting.