Delays in opening a sluice gate exacerbated flooding in a town where people were rescued from chest-high water, a council leader has said.
Council officials and residents in Worksop repeatedly asked the Canal and River Trust (CRT) to alleviate the flooding by opening the sluice gate.
The trust refused to do so and the gate was eventually opened by a firefighter several hours later.
The CRT told the BBC it would have been "unsafe" for its engineers to open it.
However, the leader of Bassetlaw District Council insisted opening the sluice gate was "vitally important" and said it was "bizarre" the CRT would not do it.
"One of the things that has most angered local people is the way in which, sadly, the Canal and River Trust did not step up to respond when they could have done," said councillor Simon Greaves.
"We knew it was vitally important that the gate was opened in order to mitigate the volume of water we were dealing with, and that's why we made repeated demands that it was opened.
"It was almost like ringing someone up that had no idea where we were, what was happening, or what the reality of the situation was and the urgency of the situation.
"For several hours there could have been more water being taken from the town centre, helping to alleviate and mitigate the crisis."
Worksop was flooded on 7 November when the River Ryton burst its banks following heavy rain.
Twenty-five properties were evacuated, while people in 65 others were made aware of the risk but decided to stay, the fire service said.
Two homeless men almost drowned when they became trapped in an industrial wheelie bin they had been sleeping in, the fire service said, while the garage door of the town's bus station was caved in by the force of the water.
Damian West, who was the duty strategic manager, said: "We had fast flowing currents of water on the streets, which basically turned into rivers."
The town was previously flooded in 2007, meaning some residents and businesses flooded for a second time had been unable to get insurance.
Kathy Frankland, site manager of the Riverside Caravan Park, said she phoned the CRT as early at 8:00 GMT and asked it to open the sluice gate - 15 hours before it was eventually opened.
"I called three times and I kept asking if it had been opened," said Ms Frankland, whose caravan and car were damaged beyond repair.
Her friend Theresa Downing, who stays at the site, said she phoned the CRT at 12:00.
"They said there was no flood alert on the River Ryton and I said 'I'm stood looking at it and I'm telling you it has burst its banks'," she said.
"They sent somebody out, there was somebody here at 1 o'clock in the afternoon, and they still did not open that gate.
"We feel very let down."
What does a sluice gate do?
- A sluice gate is a barrier designed to control the flow of water
- Opening the gate allows water to flow from one area to another
- The sluice gate in question is in a park in Worksop called The Canch
- Opening the sluice gate allows water to flow from the River Ryton into another channel of water, which eventually feeds into the Chesterfield Canal
- This lowers the level of the Ryton
The CRT said the sluice gate was in a building "deemed unsafe" for its workers to enter, and it had reported the condition of the building to the council on 16 October.
The building is owned by the council but the CRT is responsible for the sluice gate.
The CRT also said there were "some concerns about how it [opening the gate] would impact water levels elsewhere, because it's hard to determine how other areas would have been affected".
"Our staff have worked admirably at numerous locations to deal with incidents, including through the night in many cases," it added.