The Environment Agency (EA) says sandbags will remain in the River Rase while the authority continues to liaise with the landowner.
It comes as Market Rasen resident Richard Brooks claims the EA has not delivered on its promise.
In August, the EA said: “Our contractors will be completing weed control works on the River Rase in September. After these weed control works have been completed our teams will be going out to site as soon as possible to remove the sandbags and create woody habitats along the riverbank.”
Mr Brooks said: “I can’t see that any weed control work has been undertaken.
“The sacks haven’t been removed, and there has been no filling-in behind the willow hurdles.”
An EA spokesperson said: “There has been a slight delay to the removal of the bags while we liaise with the landowner to clarify what is in them, so they can be removed and disposed of properly and safely.
“They have been in the river for some time and are not posing a risk to people or the environment, so the best course is to leave them undisturbed until we have more information.”