In a written statement the pilot reported that the airplane "veered to the left" shortly after commencing the takeoff roll. The pilot reported that corrective actions were taken, however, he was unable to correct the situation before the airplane exited the runway edge. After exiting the runway, the airplane encountered a drainage ditch and nosed over resulting in substantial damage to the left wing and vertical stabilizer. The pilot reported that the winds were calm at the time of the accident. No preaccident mechanical malfunctions or failures were reported.