An Environment Agency study into making the river easier for the fish to swim up is expected to be completed next week, reports This is Derbyshire. The manager of the project said he believed work to make the river more salmon-friendly could be completed within two years.
The work, costing tens of thousands of pounds, would see pools or channels built in weirs that the fish currently find too difficult to pass.
Salmon must leap upstream in rivers before they can spawn and it is believed that the Derwent's fresh water would be a good breeding ground for the protected species.
Jim Finnegan, fisheries technical specialist in charge of the project, said Borrowash Weir was a particularly difficult hurdle.
He said: "It's a concrete block with a lip which the water runs over. When the salmon try to leap over it they land on the concrete and slip back.
"The salmon need, for example, a pool to be built which they can land in and swim on."
He said salmon could currently only go upstream in the river during flooding.
Mr Finnegan said: "If there are salmon in the Derwent they are at such low levels.
"The more habitat that they've got the better. It's very limited at the moment."
He said that a fish path could be built at Longbridge Weir in central Derby by the end of 2010, followed by Borrowash and Darley Abbey in 2011.
Improvements in Place to Help Salmon Return to Derbys
UK - Salmon could be leaping up the River Derwent in central Derby, Borrowash and Darley Abbey by the end of 2011.