The commercial pilot reported that while setting up to land in a field following a 1.3 hour flight to reestablish his solo currency, he noted on final approach that the venting system, used to release air from the envelope for descents, landings, and deflation, had malfunctioned. The pilot attempted to correct the problem while continuing to land. Immediately on landing, the balloon began to spinnaker and drag along the ground. The balloon finally came to a stop beneath powerlines adjacent to a road. The balloon sustained substantial damage to several lower panels of the envelope between the skirt and the equator. The pilot reported that not all the Velcro tabs to the parachute top of the venting system may have properly released prior to launch, which he believed was responsible for the outcome he experienced. The pilot also reported the wind was higher at the time of the accident than it was at the time of the launch, which was 5 knots.