Council workers had to hose down four houses in Geering Park, in Town Farm, after nearby sewers overflowed and the contents flooded into the ground floor.
Elsewhere, large areas of farmland in Hellingly and Horsebridge were under water and motorists faced tricky driving conditions due to spray.
More rain is expected across the county today (Wednesday) and for the rest of the week.
A family in Geering Park affected by the overflowing drains contacted the Gazette.
Barry Mewett was staying at the council-owned house for a few days with mum Sylvia Barnes, his step-brothers and young son and niece.
He said, "We were all stuck in one room. My mum's had an operation on her foot and she's had to stay glued to the sofa. I've also got my five-month old son Joseph and little niece Angel here.
"It's been a problem here for a few years. Whenever we get heavy rain the gardens flood and the drains just can't cope.
"It's the first time it's come into the house though."
Wealden District Council said it had acted as soon as it was aware the sewers were overflowing.
A spokesperson said, "We provided the four houses which were affected with sandbags and sent a crew with a jet washer to clean up.
"Southern Water will be inspecting the sewer. All tenants have contents insurance."
Southern Water estimated that, in some parts of Sussex, up to 30 millimetres of rain had fallen in three hours.
A spokesperson for the water firm said, "Due to the sheer volume of water entering our system, there have been some localised flooding incidents.
"After such incidents, we investigate to see what, if any, improvements can be made to the system."