Bags of waste and polystyrene were found in a layby at the entrance to Bishop Middleham Nature Reserve last July after a neighbourhood warden from Durham County Council was alerted.
CCTV footage showed a car entering the area and a man throwing items into the nearby hedgerow.
Checks identified that the car was hired by Stephen Ryan, 55, of White Crescent, Hesleden.
Ryan failed to respond to correspondence from the council and did not attend an interview arranged by the warden, resulting in the authority taking legal action against him.
In mitigation, Peterlee Magistrates Court heard how Ryan has health issues and that another person had used the vehicle without his knowledge on the date of the incident.
Ryan, however, pleaded guilty to knowingly causing controlled waste to be deposited and failing to an assist the investigation into flytipping.
Magistrates fined him £275 and ordered him to pay costs of £150 and a victim surcharge of £34.
Ian Hoult, the council’s neighbourhood protection manager, said afterwards that “fly-tipping is a serious offence” and added: “Hopefully, this prosecution serves as a reminder to everyone, not just to dispose of their waste correctly, but to be aware of how vehicles they are responsible for are being used at all times.
"We would also stress that there are so many ways for households and businesses to get rid of their waste responsibly.
"This includes taking unwanted items to our household waste recycling centres, paying for a bulky waste collection or even donating items which are in good condition, to a re-use scheme.”