On July 11, 1996, at 0642 central daylight time, a Bell 206B helicopter, N1082N, registered to and operated by Horizon Helicopters, Inc., as a 14 CFR Part 91 positioning flight, was substantially damaged during a forced landing near Matagorda, Texas. Visual meteorological conditions prevailed, and a company flight plan was filed. The commercial pilot was not injured. The flight was originating from Matagorda at the time of the accident. The pilot reported to the FAA inspector and in the Pilot/Operator Report that he flew the helicopter to the fueling facility and fueled the helicopter with 50 gallons of Jet A. Shortly after takeoff, while en route to pick up passengers, the engine began to lose power. While executing a precautionary landing, at about 50-75 feet AGL, the engine lost total power. An autorotation was initiated to an area of bushes that were three to four feet in height. The helicopter landed hard, and the main rotor severed the tailboom forward of the horizontal stabilizer. Examination of the helicopter by the FAA inspector revealed that the airframe fuel filter was contaminated with water and a green material. The engine driven fuel pump filter was also contaminated, and the fuel control screen had some foreign material in it. Fuel samples were taken at the fueling facility where the helicopter had just fueled. The sample taken at the fueling nozzle contained no contamination. The sample taken at the sump revealed only minor foreign material. Fuel samples were also taken at all fueling facilities the helicopter was fueled at the day prior to the accident. There was no contamination found. The pilot reported to the FAA inspector that he had taken a fuel sample during his preflight of the helicopter, and no contamination was found.