NOAA An abundance of sea life inhabits the Flower Garden Banks National Marine Sanctuary. Researchers found pollution from flood runoff reached the marine sanctuary. Flooding from major storms like Hurricane Harvey polluted coral reefs more than 100 miles offshore, according to a new study by researchers at local universities, including Rice and Texas A&M. "Those are not the reefs that we typically would think are in danger of being affected by floodwaters from the land," said Rice University researcher Adrienne Correa. "It was a big surprise." Recreational divers were the first to notice that something was wrong a few months after Houston's 2016 Tax Day Flood, during which 240 billion gallons of rainwater fell on Harris County, Correa said.