On May 21, 1999, at 1000 central daylight time, a Piper PA-18-150 airplane, N9670P, was substantially damaged while landing at an unimproved air strip/dirt road near Palacios, Texas. The private pilot, sole occupant, was not injured. The airplane was registered to and operated by Trull Service Company of Palacios, Texas. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 local business flight. The flight originated at 0930 from another private air strip. According to the pilot, he was conducting a routine inspection of a canal irrigation system for a private rancher. The pilot was landing on a dirt road (used as an unimproved air strip), which paralleled one of the canals. During the landing flare, a "slight crosswind from the left" drifted the aircraft "slightly" to the right. The pilot corrected for the wind by lowering the left wing, which contacted tall weeds adjacent to the landing area. The airplane exited the left side of the air strip where it rolled up the canal bank, turned 90 degrees to the left, and nosed over into the canal. The airplane came to rest on its nose and right wing in eight inches of water. The pilot added that he had landed in the same area a few weeks prior to the accident flight and noted that the grass was much shorter then. He stated that he was unaware that the grass had grown so much since the last time he was there. The right wing was bent up outboard of the wing strut and bent aft at the wing root. The engine firewall was buckled to the left. According to the pilot, he had accumulated 3,793 hours of total flight time, of which 3,400 hours were in the same make and model as the accident aircraft.