FLOOD gates, protective walls and buildings which will form barriers to rising river levels are detailed in proposals for how Derby would deal with a massive flood.

More than 3,500 properties in and around the city centre are at risk of flooding from the River Derwent.

Experts have been working on how the city could reduce that number and protect buildings and new developments against a significant flood, the type likely to be seen once in 100 years.

Now, the Environment Agency and Derby City Council have produced their initial proposals, on which they want the views of residents and businesses.

Christine Durrant, director of planning and facilities management at the city council, said: "This is a draft master plan and the work is very long-term but we need to get people thinking about how we protect this city from flooding in the future."

Proposals in the plan include creating green spaces in the city centre which will be allowed to flood.

Flood gates would also be created on some of the key roadways in the city, such as Exeter Bridge, which would be closed when the road flooded to protect the city centre.

Flood defences are already being incorporated into the basement of the refurbished Council House.

Innes Thomson, Environment Agency flood-risk manager, said: "In the Lower Derwent Valley, 3,600 properties are at risk during a severe flood.

"The master plan is a key step in safeguarding thousands of people and properties along the river banks, from Darley Abbey Mills in the north to Derby Junction Railway Bridge in the south."

While the aim of the work has been to avoid unsightly, towering flood defence walls where possible, there could be areas where this is still an option.

They include Duke Street, in the Strutts Park area.

There the council wants to hear more from residents about what they would like to happen.

Mrs Durrant said: "We have no preferred options for this area and we want to hear from residents and communities about what they would like."

Other options, apart from seeing 9ft walls built, include accepting the flood risk or improving homes to be more resilient to flood.

Elsewhere along the Lower Derwent, the aim is to help bring forward regeneration by showing developers that they can still build.

Rob Salmon, head of spatial planning and climate change at the city council, said: "That would be done through incorporating flood defences within the buildings themselves, such as undercroft car parking."

One area this could benefit is the former Aida Bliss factory site, in City Road.

Mr Salmon said: "There was a desire for a residential development here but because it is in a high flood risk zone that's not been an option. What this plan sets out is setting development back with some parkland at the front by the river.

"The area behind that could be developed with residential with flood defences built."

Further south, towards Etruria Gardens, there is an existing flood wall.

Redevelopment there has been discounted because of the impact on homes and therefore the main option is to create a new flood defence.

It is thought that would be through a natural type of grassed bank or a higher wall.

City Road would be regenerated with flood defences built into the new buildings which would be set back from the river's edge. The area alongside the river itself would be landscaped.

The same approach would be taken to secure development in Derwent Street, in the area known as North Riverside.

There, previous plans for leisure and retail development were scrapped because of the uncertainty about how the flood risk would be managed.

Under the latest proposals, defences would be built into new buildings along the river.

That would provide a "defended line" behind which major new development, including homes, could take place.

The area between that new development and existing buildings along Stuart Street, which line the river, would allow a corridor to carry flood waters.

Space for that would be created by removing existing buildings east of Stuart Street.

They would be replaced by a new leisure facility and a new city centre park.

In Meadow Lane, where the Derby Telegraph offices are, the ideal plan is to relocate the bus depot and redevelop the site with new defences ready for future development.

Changes to the highway would also give alternative routes to access the site.

Councillor Matthew Holmes said he believed that, far from putting off developers, the flood plan would encourage them.

"Developers have been waiting to see what strategy the city has for flooding before coming forward with plans," he said. "Our approach is very much to encourage development."

On the other side of the river, the majority of the buildings, including the Silk Mill, are designed to cope with a flood.

Here the focus is on improving footpaths alongside the river for pedestrians and cyclists. In other areas, such as Darley Abbey Mills, the focus would be on strengthening flood defences to protect one of the city's most important historic assets.

A footbridge would be built to provide an escape route from the mills in a flood and protect the toll bridge. Flood gates would be installed at both ends of Haslams Lane.

The Darley Abbey Playing Fields would see existing flood defences improved and landscaped earth mounds created further north than the existing defence line.

Today, the plans are being published for people to have their say.

The consultation will run until Friday, March 9.

Mr Holmes said: "I know that we are facing many challenges at the moment and it can be difficult to focus on a plan to tackle a 1%-a-year risk of flooding, but we need to prepare.

"I'd like the residents of Derby to tell us what they think of the plans so far and I would urge everyone to take the time to read them and comment."

A dedicated website and phone line have been set up for people to contact.

Questions which are being frequently asked will be added to that website.

Copies of the draft plan will also be made available in district libraries.

In addition, a consultation leaflet has been distributed to about 7,000 properties in and around the Lower Derwent.

People can call 0800 121 4633 or visit www.ourcityourriver. co.uk.