The pilot was competing in the Australian National Gliding championships. An outlanding became necessary when thermal activity declined and an approach was made to a dry field which was used for irrigation. On the downwind leg of the circuit, the pilot noted that a ditch crossed the field, however this ditch was not visible to him when on final approach. During the landing roll the glider collided with the ditch. The pilot had overflown a more suitable landing area, with the intention of making the outlanding closer to the destination aerodrome. The paddock ultimately selected was the most suitable in the vicinity, but required an approach between clumps of trees and alongside a power line. During the latter stages of the approach the pilot's vision was affected by sun glare.