Police are advising motorists to avoid the A127, particularly at the Rayleigh Weir, which remains flooded after Saturday's heavy rain.
Officers are working with the local authority to get the water pumped away and reopen the road as soon as possible.
Over 200 incidents of flooding were reported to police on Saturday with areas worst affected including Southend, Canvey, Maldon, Burnham, Battlesbridge and Benfleet.
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After what's been the hottest day in the region for almost 10 years there are warnings tonight about the dangers of swimming in open water.
Today was the hottest day of the year so far but temperatures will be down a little tomorrow with the risk of thunder.
A sizzling day for the Anglia region with temperatures rocketing into the mid 30's.