The Country Land and Business Association said the “disgraceful behaviour” blights the countryside and warned that the true extent of fly-tipping across England is probably even higher than feared.
Department for Environment, Food and Rural Affairs data shows 1,537 fly-tipping incidents were reported to North Kesteven Council in 2020-21.
This was more than double the 751 discoveries made the year before, and the highest number since comparable records began in 2012-13.
However, no fines resulting from court convictions were issued in the area last year – down from two in 2019-20.
North Kesteven District Council carried out 1,032 enforcement actions in 2020-21.
Across England, a record 1.1 million incidents of rubbish dumped on highways and beauty spots were found in 2020-21, up from 980,000 the previous year.
But the number of court fines halved from 2,672 to just 1,313 – with their total value decreasing from £1.2 million to £440,000.
The CLA, which represents rural businesses, said the vast majority of fly-tipping occurs on private land, which the figures do not cover.
Mark Tufnell, president of the CLA, said: “These figures do not tell the full story of this disgraceful behaviour which blights our beautiful countryside.
“Fly-tipping continues to wreck the lives of many of us living and working in the countryside – and significant progress needs to be made to stop it.
“It’s not just the odd bin bag but large household items, from unwanted sofas to broken washing machines, building materials and even asbestos being dumped across our countryside.”
North Kesteven saw 13 fly-tipping incidents per 1,000 people last year – which was still below the average across England, of 20.1.
Household waste accounted for 679 (44%) incidents last year, while 54 separate incidents were classed as large enough to fill a tipper lorry.
These cost the council £18,900 to clear up.
Sarah Lee, director of policy and campaigns at the Countryside Alliance, said: “From quiet rural lanes and farmers’ fields to bustling town centres and residential areas, fly-tipping continues to cause misery across the country.
“Lockdown and the subsequent closure of tips only exacerbated this situation and we would urge local authorities to think very carefully about preventing access to these facilities in future.”
The Government said the first national coronavirus lockdown impacted many local authorities’ recycling programmes, and that changes to household purchasing may also have driven the increased fly-tipping.
Resources and Waste Minister Jo Churchill said: “During the pandemic, local authorities faced an unprecedented challenge to keep rubbish collections running and civic amenity sites open, and the Government worked closely with them to maintain these critical public services.
“We have already given local authorities a range of powers to tackle fly-tipping and we are going further; strengthening powers to detect and prosecute waste criminals through the new Environment Act, consulting on introducing electronic waste tracking and reforming the licencing system.”