The move comes as a red alert for rain and wind was extended to a wider area of Scotland. The warning comes into effect at 6pm today and now covers an area stretching from southern Aberdeenshire and Angus to the outskirts of Dundee and Perth.
Amber and yellow warnings are also in place in other areas of the UK.
The Met Office red weather warning runs until noon on Friday, with between 10-15cm (4-6in) of rain expected to fall within the warning period and some locations likely to see between 20-25cm (8-10in). Angus Council earlier issued a warning that north Angus in particular could be badly affected.
Residents have been warned of a danger to life from fast flowing or deep floodwater and extensive flooding to homes and businesses.
A severe flood warning is set to be put in place for the River South Esk area and those affected are being advised to leave their homes. Council will be going door to door with around 360 properties expected to be evacuated.
A rest centre will be set up from 3pm.
Train and bus services in affected areas have already been cancelled and driving conditions are likely to be treacherous because of spray and flooded roads.
There could also be a loss of power and other essential services, such as gas, water and mobile phone services, with some communities potentially being completely cut off for several days.
The Scottish Environment Protection Agency has said there is a specific focus on the Brechin area, which has suffered bad flooding in the past.
The water level around the town, is expected to be "close to the top" of the flood defences, with a significant risk that water going over the top would lead to a "rapid inundation" to surrounding areas.
A spokesman said that there is particular concern this could happen overnight into Friday.
He said: "Take action now to protect yourself and your property.
"Hazards can be hidden, so please don't walk or drive into flood water.
"Remember that not only is flood water likely to be dirty, 30 cm of fast flowing water can move an average family sized car, and just 15 cm of fast flowing water could be enough to knock you off your feet."