The Syrian military says its forces have taken control of the main water source for the capital Damascus after reaching a deal for rebel fighters to withdraw from the region.
Water shortages have affected more than 5 million residents in the Damascus area since late December, but state television said the national flag was now flying over a pumping facility.
The Syrian army and its allies launched an offensive last month to drive insurgents from the Wadi Barada valley, which lies north-west of Damascus, and to recapture a major spring and the pumping station.
Government forces entered the village of Ain al-Fija, where the spring and pumping station are located, early on Saturday.
"The Syrian army has entered Ain al-Fija ... and raised the Syrian flag over the spring installation," a statement by the unit said.
Teams were preparing to enter Ain al-Fija to fix the pumping station and the army had secured control of the village, it added.
Rebels had controlled the valley since 2012.
Under the deal reached between the Government side and local representatives, rebels hailing from outside the Wadi Barada area would leave for the north-western province of Idlib, an insurgent stronghold, carrying light weapons, the Observatory said.
Rebels from Wadi Barada would be allowed to leave too, but could also opt to stay and serve with pro-government forces, it added.
The Syrian Government has struck similar local ceasefire deals with the opposition in several western parts of the country, usually involving the transfer of rebel fighters and their families to Idlib.