Sure signs for replacing a toilet include recurring clogs, porcelain cracks and scratches, and needing to replace too many parts in the tank. But these days, one reason reigns supreme for replacing the porcelain throne: water conservation. Toilet flushing accounts for nearly 30 percent of residential indoor water consumption according to the Environmental Protection Agency (EPA). You can save $2,000 over the lifetime of the toilet in your home by going with a high-performance, low-flow option. That long-term savings trumps an inexpensive, temporary fix on an older toilet model.