Plans to return Bradford Beck to the “idyllic country stream” it was before the industrial revolution have raised concerns within Bradford Council.

Proposed by the Aire Rivers Trust, Bradford Council officers fear the scheme to naturalise the 11km watercourse could lead to increased flood risks, and prove costly to maintain, although it is still viewed as being a “broadly acceptable” idea.

The trust published a report called Bradford Becks, a new lease of life, last month, and it will be discussed by the Council’s Environment Scrutiny Committee at City Hall at 5.30pm on Tuesday.

Because the beck in classed as an ordinary watercourse, the Council is responsible it. However, responsibility for its repairs and maintenance lies with landowners along its route.

Originally a country stream, the Industrial Revolution turned the beck into what the trust describe as a “fetid repository for raw sewage and industrial effluent”, once known as the country’s dirtiest river. It was culverted in the early 1900s, parts of its route were altered and some stretches are now underground.

The trust wants to uncover the beck, returning it to a more natural state and encouraging wildlife. The man-made culverts would be filled in and the beck diverted back to natural beds.

The trust’s report says: “Rivers that are lost are just drains that cannot be enjoyed, or be assets to the city. They have no ecological value and disconnect people from their environment and the consequences of their actions.”

It also wants better signs and new nature trails along the beck.

Now the trust wants Bradford Council to accept its plan, and tie it in with its own future aspirations for the city centre and the Canal Road corridor.

But officers are worried that turning it more natural could cause problems. A report to next week’s committee by drainage engineer Tony Poole says: “The naturalisation of the beck raises three main concerns – increased sedimentation, alterations to flow velocity and increased maintenance costs.

“Simplistically, straight, smooth culverts are the best way of reducing debris and sediment build up. However providing this does not increase flood risk there can also be gains both in terms of ecology and amenity.”

Because responsibility for ownership lies with landowners, the report says “the extent to which we can enforce change is limited”.

It describes the trust’s ideas as “broadly acceptable” as long as they do not cause higher flood risks or hinder development along the route of the beck.

The Council has previously blocked efforts to bring the waterway under Environment Agency control, which it said would constrain development.