Residents on the outskirts of Bangkok have been told to evacuate as authorities in the Thai capital fight a losing battle against massive volumes of water moving towards the sea.

Authorities have been battling to fortify makeshift flood walls on the edge of the city, but have finally admitted defeat.

This weekend is going to be the real test of Bangkok's flood mitigation system, as water flows from the north against high tides for the next few days.

Much of the water heading towards the Gulf of Thailand is flowing around the north-east side of the city with floodgates into the CBD locked.

Floods of up to 1 metre are expected and residents of Bangkok's outer north-east were urged not to panic as they were told to leave.

The government was still confident the CBD would stay dry but many were sandbagging anyway as insurance against the coming weekend's high tides.

Some residents who are angry that their homes are flooded have been trying to free trapped water by dismantling temporary sandbag walls, which are now being guarded by the army.