The pilot reported that during proficiency training in the tailwheel-equipped airplane, during the landing roll, he began to apply brake pressure. As his main landing gear wheels rolled over a water bar, he shifted in his seat and inadvertently applied more brake pressure. Subsequently the airplane nosed over.

The gravel runway is sloped and has two water bars that cross over the runway.

The airplane sustained substantial damage to the empennage.

The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.