When the pilot was about 600 feet above the ground he realized that he was committed to an outlanding. He noted that the selected paddock had one set of powerlines parallelling his intended landing direction. On short final at about 100 feet above ground level the pilot saw a second powerline obliquely crossing the intended landing path. He turned right and carried out a landing in another paddock. The glider landed downwind and the pilot initiated a groundloop in an attempt to avoid a collision with a fence. The manoeuvre was not successful and the glider came to rest straddling the fence. The pilot had evidently delayed his planning for an outlanding until the glider was substantially below the minimum height of 2000 feet recommended by the Gliding Federation.