Some mainlanders have compared Hong Kong's restrictions on milk powder exports to biting the hand that gives it water.
There is a false perception that Hong Kong survives on an "unconditional" supply of water from the mainland.
Hong Kong pays the central government for water - at a cost that is about 300 times more than what Malaysia charges Singapore. And we still have to clean it up, because the water from Dongjiang was classed as "non-drinkable grade" in the State Oceanic Administration's recent report.
This deal, adopted in the Guangdong-Hong Kong Water Supply Agreement, has led to massive wastage. Over the past eight years, rain water worth more than HK$1 billion has been pumped into the sea.
Under the agreement, Hong Kong pays an annual lump sum to "secure a reliable and flexible [amount] of Dongjiang water". But this allows no flexibility for wetter years, when Hong Kong might not need so much water.
The pact is being renegotiated before it expires at the end of this year. Therefore, it is high time to push for the inclusion of a volume-based charging policy to reduce waste. This would also allow the authorities in Guangdong to better manage the supply of water to the upper reaches of the Pearl River Delta.
The renewal of this agreement presents a good opportunity to adjust our long-term water policy. We need to reduce our dependence on imported water in future, and promote sustainable ways of using this precious resources.
As the demand for water continues to rise in cities such as Dongguan and Shenzhen, there is no guarantee that the mainland will continue to supply us with water.
The planned construction of a desalination plant in Tseung Kwan O is the first step to diversifying our water resources. The re-use of greywater - water from bathroom sinks, showers, tubs and washing machines - and rainwater should also be considered.
Hong Kong should also come up with a more realistic water pricing plan, and set a target for reducing domestic water usage, similar to the one laid out by our regional competitor, Singapore.
In the best-case scenario, we should hope that one day Hong Kong will have extra water that it can give to mainland cities.
Otherwise, Hong Kong may have to implement a new restriction against panic buying - this time for bottled water.