Israel Water Authority director Prof. Uri Shani told the weekly cabinet meeting on Sunday that Israel has received less than half of the average seasonal rainfall so far this winter.
The Jerusalem Post quoted Shani as warning the ministers that the three sources of the Jordan River, which feeds Israel's largest fresh water reservoir - the Sea of Galilee - had never been so low at the beginning of December.
He said that if the rest of the winter is relatively dry, and there is every indication that it will be, the government will have to impose severe water restrictions come spring.
Shani said the first victim of the drought will be the agriculture sector, with over 100 million cubic meters of fresh water being cut from what is usually alloted to farmers.
Israel will also likely expand its current restrictions on watering private and public gardens to a full ban.
At present, ministers and Water Authority officials are careful to avoid talk of rationing household water, but National Infrastructures Minister Binyamin Ben-Eliezer did urge Israelis to continue voluntarily conserving water even though the winter has arrived.