Flooding damage from last fall’s Hurricane Sandy involved more than houses and cars in New York and New Jersey. (MICHAEL REYNOLDS/EUROPEAN PRESSPHOTO AGENCY)

Hurricane Sandy sent 11 billion gallons of sewage from East Coast treatment plants into streams, canals and roadways, according to a report released last week, six months after the storm hit. That total is equal to New York’s Central Park stacked 41 feet high with sewage. More than 90 percent of the spills occurred in New York and New Jersey. Of the total, 3.45 billion gallons was raw, untreated and unfiltered, said the report, which was based on state and federal data and on estimates in cases where electronic monitors failed. The remainder was partially treated.

“What we learned is just how vulnerable this system is to floods, storms and climate change,” said Alyson Kenward, the report’s author and a researcher at Climate Central, an organization that provides research on global warming for policymakers and the public. “Our system isn’t designed to handle these kinds of storm surges and the sea-level rise associated with climate change.”

Sewage plants are typically placed in low-lying areas, near bodies of water. As a result, the scientists responsible for the study say, the plants are vulnerable to storm surges and coastal flooding, which is linked to 94 percent of the sewage that overflowed.

New York state will need to spend about $2 billion repairing plants damaged by the storm. New Jersey plans to allocate $1 billion for repairs and additional funds for shoring up plants in preparation for the next storm, according to Climate Central.