Groups involved in the clean up included Clean Up Australia, Tamar Natural Resource Management, West Tamar Landcare as well as both George Town and West Tamar councils.

Tamar NRM program co-ordinator Gill Basnett said on average each of the 24 sites had about 10 to 15 people, with some sites eclipsing 30 volunteers.

"It was such a success that we are already planning next year's Catch it in the Catchment event and we hope even more people will join in. In the long run, though, we hope these types of events won't be needed as more people put their waste in the bin," she said.

Locations along the Tamar Valley included Greens Beach, Beauty Point, Kelso, Rowella, Rosevears, George Town and Low Head.

West Tamar mayor Christina Holmdahl was part of clean up efforts at Redbill Point near Beauty Point. She said the group at Redbill was extremely lucky not to find too much trash contaminating the well-maintained area.

"It's unfortunate that we have to do these things because a lot of the time when the places are trashed it's not by the people that live there ... sometimes the community does have to roll their sleeves up and do a bit of a tidy," Cr Holmdahl said.

"I think it was a wonderful initiative and as I understand there was very good support from all community groups in general."

Ms Basnett said an unfortunately common item found by volunteers on the day was cigarette butts.

"Cigarette butts are a prime example because people think it's only small and it will break down and it doesn't matter, but they actually take a long time to break down and they're actually full of poisonous chemicals," Ms Basnett said.

"Certainly in key dog walking areas you see dog poo bags that have either come off the roll or people collect the dog poo and leave the bag."