On July 23, 2017, about 2230 central daylight time, a Beech G35, N4216D, was substantially damaged when it struck an irrigation canal off the end of runway 13 at Wichita Valley Airport (F14), Wichita Falls, Texas. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 without a flight plan. The pilot, the sole occupant aboard, was seriously injured. The local flight originated from Grand Prairie (GPM), Texas, about 2130.According to the pilot's accident report, he departed GPM about 2130, and received flight following and a clearance into Class B airspace. The flight proceeded normally until he entered the downwind leg for runway 13 at F14. He noted scattered thunderstorms ahead. On final approach, he thought the airplane was too high and he considered making a go-around. He felt strong downdraft and encountered heavy rain and turbulence. He also observed several lightning strikes ahead. The pilot made the decision to land and risk running off the end of the runway rather than possibly entering the thunderstorm. The pilot said he did not realize there were 6-foot tall berms on either side of a drainage ditch 50 to 60 feet from the end of the runway because of the tall weeds obscured them. There was also standing water on the second half of the runway. The airplane went off the end of the runway and struck the first berm. The impact rendered the pilot unconscious. When he regained consciousness minutes later, the airplane was in a drainage ditch and water had filled the cockpit. He remained in the airplane until daylight, extricated himself, and walked to a nearby house where he called 9-1-1. Federal Aviation Administration (FAA) inspectors examined the airplane and reported finding substantial damage to the forward fuselage and firewall. Weather observations recorded at Sheppard Air Force Base/Wichita Falls Municipal Airport (SPS), located 7 miles to the east of F14, reported winds varying from 060° to 360° at 16 to 20 knots, and gusting from 21 to 29 knots, with a peak wind at 35 knots. There was a thunderstorm in the vicinity, with lightning observed in all quadrants.