cheer-leading by insurgents on social media. Why when they claim that the government bombed the place?

On December 29 the UN Office for the Coordination of Humanitarian Affairs issued an alarm about the water crisis:

The United Nations is alarmed that four million inhabitants in Damascus and surrounding areas have been cut off from the main water supply since 22 December. Two primary sources of drinking water- Wadi Barada and Ain-el-Fijah-which provide clean and safe water for 70 percent of the population in and around Damascus are not functioning, due to deliberate targeting resulting in the damaged infrastructure.

One of the two springs, Al-Feejeh, has now been retaken by the Syrian army. 1,300 civilians from Ain AlFeejeh, the nearby town with the treatment facility, have fled to the government held areasand were taken in by the Syrian Red Cross. The other spring and the treatment facility are still in Takfiri hands. The government has said that it will need some ten days to repair the system after the Syrian army has gained control of the facilities. That will still take some time.

Western media have hardly taken notice of the water crisis in Damascus and their coverage seems to actively avoid it. A search for Barada on the Washington Post website brings up one original piece from December 30 about the freshly negotiated ceasefire. The 6th paragraph says:

Airstrikes pounded opposition-held villages and towns in the strategically-important Barada Valley outside Damascus, activists said, prompting rebels to threaten to withdraw their compliance with a nationwide truce brokered by Russia and Turkey