The pilot noticed a significant loss of engine power while maneuvering on a local area flight. The pilot began looking for a suitable place to land and noticed a sandbar along a river. As he approached the river he applied carburetor heat and the engine power began to recover. At this time the airplane was at tree top level along the river when the pilot noticed wires crossing the river. The pilot was unable to reestablish a climb and avoid the wires. The airplane struck the wires and impacted inverted on the sandbar. The pilot and passenger received minor injuries. Weather conditions at the time of the accident were conducive to carburetor icing at cruise and glide power settings with a temperature of 34 degrees Celsius and dew point of 23 degrees Celsius. According to a Federal Aviation Administration inspector on scene, there were no pre-impact anomalies noted.