Tower Of Power founders Emilio Castillo and Stephen "Doc" Kupka wrote this song in response to a 1971 oil spill in the San Francisco Bay caused by two tankers colliding. Castillo and Kupka were still in high school, and it was big news.
"It was one of the first oil spills ever," Castillo said in a Songfacts interview
. "There were all these seagulls that were covered in oil and they were trying to rescue them. That's what spurred this conversation that Doc and I had. He was telling me that he got called into the principal's office when he was about eight years old. They were concerned about his behavior or something. The principal said, 'Stephen, is there anything troubling you?' And he looks at the guy and he says, 'Yes, there is. What are we going to do when we run out of oil?' And the principal says, 'Stephen, go back to class.'
He was telling me this story and we were laughing about it, but we started to think about it: It can't last forever. What are we going to do? We should write a song about that. So we wrote this song, 'Only So Much Oil In The Ground.'"