The pilot intended refuelling at the previous landing point but he found that fuel was not available. After re-checking his fuel requirements he was satisfied that the flight could be accomplished with almost full reserves. The weather deteriorated and groundspeed reduced during the flight, causing the pilot to become concerned about flight visibility and fuel endurance. He elected to make a precautionary landing near a homestead but during the landing roll the aircraft ran through a fence and collided with a ditch. Although the pilot had lost time on earlier legs of the flight he made no similar allowance for the subject leg, nor did he divert to a suitable refuelling point. Having decided to carry out a precautionary landing, the pilot did not make a low-level inspection of the area. The approach to land was made downwind and the aircraft did not touch down until it was less than 220 metres from the end of the 2000 metre paddock selected.