Essex Fire Service said firefighters and control operators dealt with some 500 flood and weather related incidents and calls from around 3pm yesterday.
Of those more than 400 were from Canvey Island - the worst hit area in the county. Seven pumping appliances focused on the south east corner of the island where the flooding was most severe.
Hundreds of firefighters are going on strike in Essex today.
The Fire Brigade union says members will walk out at 10 o'clock in the morning, returning at six.
The Essex Fire Service says "excellent contingency plans" are in place.