THE PILOT REPORTED THAT DURING TAKEOFF CLIMB AT ABOUT 200 FEET AGL, THE ENGINE LOST POWER. SHE TURNED BACK TO THE AIRPORT, BUT BECAUSE OF INSUFFICIENT ALTITUDE, THE AIRPLANE STRUCK TREES SHORT OF THE AIRPORT. THE POST ACCIDENT EXAMINATION REVEALED ABOUT ONE HALF CUP OF WATER IN THE AIRPLANE BELLY SUMP AND IN THE CARBURETOR. IT WAS ALSO DETERMINED THAT AN AIRWORTHINESS DIRECTIVENESS PERTAINING TO WATER CONTAMINATED FUEL CAUSED BY IMPROPER FUEL CAP SEALS WAS NOT COMPLIED WITH.