The items discovered by Scottish Water staff have included golf clubs, beer barrels and false teeth.
The authority's asset management director Geoff Aitkenhead said that an incredible variety of items had been hauled out of Scotland's sewers.
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A gentleman called us up to demand that we drain a sludge tank to get back his false teeth that had fallen down a toilet
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Geoff Aitkenhead
Scottish Water
He said someone had smashed up a sofa before dumping the piece down manholes near one of Scottish Water's pumping stations at Coatbridge in North Lanarkshire.
"People seem to be extremely determined when it comes to disposing of stuff they apparently no longer have need for," said Mr Aitkenhead.
"We also had an incident in Aberdeen when a gentleman called us up to demand that we drain a sludge tank to get back his false teeth that had fallen down a toilet.
"Why anyone would want them back is beyond me."
Closer inspection
The list of items found in sewers also included carpets, television sets, beer barrels, golf clubs, garden tools and even a tree.
"In another case, one of our operatives got the fright of his life when he found what he thought was a body," said Mr Aitkenhead.
"On closer inspection it turned out to be a large doll."
He said that such incidents could cause major blockages in the sewerage system and lead to major operational problems at treatment works, pumping stations or storage tanks.
He said: "There needs to be greater awareness of the problems that careless dumping down toilets can cause."
Scottish Water also highlighted the risk to staff when addicts dispose of hypodermic needles down the toilet.
And the authority estimated that it had cost £900,000 to clear blockages caused by the dumping of grease and fat down drains.
Mr Aitkenhead said that this mainly came from fast food shops.
Business customers
"Fat is not readily removed by sewage treatment processes and can pass through the treatment plant into the sea or into a river," said Mr Aitkenhead.
"The solution is for people to avoid disposing of grease and fat into drains and sewers.
"We are reminding our business customers of the need to make sure they have fat removal procedures, where applicable, and that these are working properly."