Wright’s drainage systems weren’t always up to the task.

Gunny Harboe has led the renovation of Unity Temple, one of Wright’s only designs for a religious space. The building is considered a masterpiece, and has been nominated to become a UNESCO World Heritage Site, along with Hollyhock House and eight other Wright buildings.

“One of the big problems at Unity Temple has been the fact that the internal drainage system was undersized,” Harboe says. “It was never really big enough to accommodate the amount of water that wanted to go through it.”

Jeffrey Herr says the drainage system in Hollyhock House also had to be replaced.