People living in Jaywick, Mistley and West Mersa are being told to evacuate their homes immediately as the flood warning is once again put at the highest levels.
Earlier today officials had downgraded the alerts from "severe flood warning" to "flood warning" for the Essex coastal villages after fears about water levels this morning and this afternoon seemed to subside.
But police now say the high tide expected at around 12.50am will once again pose a danger to life.
A severe flood warning for the area is back in place and officers triggered a full evacuation plan for all three villages at 10.40am.
Ch Insp Russ Cole, of Essex Police, said it was safest to get people out of their homes during daylight hours.
A rest centre has been set up at Tendring Education Centre at Jaywick Lane in Clacton. Residents will be able to stay there until it is safe to return to their homes.
It can accommodate up to 1,600 people.