On October 10, 1998, approximately 1600 mountain daylight time, a Cessna 210A, N9449X, was destroyed when it collided with water during an approach to land at Provo Airport, Provo, Utah. The pilot and his passenger were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the local flight being conducted under Title 14 CFR Part 91. The flight originated at Spanish Fork, Utah, approximately 1550. The following is based on a telephone conversation with the pilot and his written accident report. The pilot said that he was low on his approach to runway 36, so he "quickly pushed the throttle in" and there was a total power loss. The pilot said he turned the fuel pump on to HIGH boost, and pushed the mixture in to full rich. He then pulled the mixture back to idle cut-off. The engine sputtered momentarily. Attempts to restart the engine were unsuccessful. The airplane was ditched in Utah Lake, just short of the approach end of runway 36. The airplane was retrieved from Utah Lake and taken to Spanish Fork Flying Service, Spanish Fork, Utah, where, on October 13, 1998, it was functionally tested. The engine operated satisfactorily at all power settings. The pilot said a Spanish Fork Flying Service mechanic told him he had flooded the engine when he "quickly pushed the throttle in." According to the "Forced Landing Procedures (Complete Engine Failure)" in the Cessna 210A Owner's Manual, the following should be accomplished: "1. Pull mixture control knob to idle cut-off. "2. Turn fuel selector valve handle to 'BOTH OFF.' "3. Turn off all switches except master switch. The Cessna 210A Owner's Manual also addresses the use of the auxiliary fuel pump switch: "The auxiliary fuel pump switch controls both of the electric auxiliary pumps which supply fuel flow for starting, and for engine operation if the engine-driven pump should fail. The switch has three positions: 'HIGH,' 'OFF,' and 'LOW PRIME.' The 'LOW PRIME' position operates only one pump, providing sufficient fuel for priming, starting and vapor purging. The 'HIGH' position operates both pumps and closes the vapor return line, supplying sufficient fuel flow to maintain flight. However, the auxiliary system is not to be used during normal operation, because, with the engine-driven pump functioning, a fuel/air ratio considerably richer than best power is produced and any vapor in the system cannot be returned since the vapor return line is closed. NOTE: If electric pumps are turned on with engine stopped, intake manifolds will be flooded unless mixture control is in idle cut-off."