MELBOURNE, Fla. -- The Brevard County Emergency Operations Center reported on Wednesday that between 40,000 to 50,000 beachside residents are affected by a sewage backup caused by Fay floodwaters.

Parts of north Melbourne have received rain amounts approaching 2 feet, according to the National Weather Service.

One report to the National Weather Service in Melbourne indicated that 21.7 inches had fallen since Tuesday, when Fay hit Brevard County.

More than 15 inches of rain had fallen at the Weather Service Office in Melbounre, Local 6 News partner Florida Today reported.

More rain is expected.

"The rainfall is anchored on that south side," said Randy Lascody, a forecaster with the National Weather Service Office in Melbourne.

Heavier rains are generally associated with the right front quadrant of a storm, but Fay has been an exception.

Tropical Storm Fay's intense rainfall has "overwhelmed" the 200-mile network of canals providing drainage for most of Palm Bay and West Melbourne, the top manager of the canals said on Wednesday.

"There's just too much water, there's too much rain," said Al Pinnell, director of the Melbourne-Tillman Water Control District. "It's operating to the fullest extent that it can."

Pinnell said he had recorded more than 10 inches of rain at his headquarters since Tuesday. As of 1 p.m., the main canal's water level measured 13 feet above sea level at its outfall, where it enters into Turkey Creek. The rest of the roughly 70 canals are at "bank full" capacity.

Pinnell said he had not seen this volume of water since joining the water control district in 1982.

Four gates that discharge water into the Indian River Lagoon through Turkey Creek -- two of them operated automatically and two more manually -- have been open since Tuesday afternoon, as is typical during hurricane-type events, Pinnell said.

"These canals are full," he said. "There's nothing more we can do until water levels recede."