Mansfield Magistrates' Court heard Nottinghamshire Council staff were using a lightweight all-terrain vehicle to travel around the park whilst emptying litter bins at the Robin Hood Festival in August 2011.
Nottinghamshire County Council of County Hall, Fox Road, West Bridgford pleaded guilty to breaching Regulation 3(1)(b) of the Management of Health and Safety at Work Regulations 1999. It was fined £6,000 with £5597 costs.
The utility vehicle on which two staff were travelling in went out of control and collided with a three-year-old child who was seated in a pushchair. The little girl suffered bruising to her head and leg.
The Health and Safety Executive prosecuting told the court it had found the council had not undertaken a suitable and sufficient risk assessment - and if the council had done so it would have come up with a different way of collecting litter.
The court also heard the council had received previous warnings in the shape of HSE Improvement Notices in relation to undertaking risk assessments.