It happened around midnight on the Galveston Bay side of the Bolivar peninsula.
"At about one o'clock this morning, about a quarter to one, we received a call from a captain of a tug boat, who reported that the barge that he was pushing had struck another barge moored at the Bolivar Fleeting area."
Coast Guard spokesman Mario Romero says no crewmen were hurt, but one of the barges punched a hole in the other, and some of its chemical cargo leaked into the bay.
"Both barges were damaged, but the one barge that was struck at the Bolivar Fleeting Area sustained a softball sized hole in a cargo tank and started to leak cyclohexane."
Cyclohexane is one of the chemicals that's added to gasoline to make it more flammable.
"We are trying to determine any environmental damage at this time, however, the source of the spill has been secured. There's no more leaking out."
Romero says they're trying to clean up what they can of the spill, and the barge owners are transferring the remaining loads into other barges. They're also planning to remove the damaged barges from the area, and to make that work easier and safer, Romero says:
"We've closed the Intracoastal Waterway from mile marker 340 to mile marker 350, about ten miles surrounding the barge collision."
Jim Bell, KUHF Houston Public Radio News.