A colossal £100 million project to overhaul Bradford's water mains and sewerage network has been completed.

The Bradford Strategy, which began in 2002, has seen Yorkshire Water carry out one of its biggest ever capital schemes to upgrade the city's infrastructure.

The period has seen large-scale investment in renewing water mains along the 25-kilometre route of Bradford's main ring road as well as hundreds of kilometres of smaller distribution mains.

About £10 million has also been spent on upgrading Chellow Heights water treatment works to raise the quality of water which goes to customers.

Meanwhile, major work to the sewerage network has increased storm water storage capacity to reduce flooding at times of heavy rain.

Ian Johnson, Yorkshire Water project manager, said: "The work we've completed over the last few years has been one of the biggest capital schemes we've ever done.

"It has given the customers of Bradford the best quality of water, through pipes which are in great condition, and has also improved the local environment.

"We do realise that the intensity of work within the Bradford Strategy has caused some inconvenience for road users and customers and we would like to thank them sincerely for their understanding."

New technology has been developed over the work period, meaning Bradford residents were some of the first to benefit from shorter cut-off times when pipes were being relined.

Yorkshire Water said shut off times were reduced from 36 hours to less than eight hours because the company started using a new type of pipe lining which sets more quickly.

People living and working in Bradford were also some of the first in the country to benefit from the "CoverCat" large bore piping rig. The rig, which is the biggest machine of its kind, can line large diameter water pipes without the need to dig trenches in the roads, reducing the scale of disruption.

Terry Thompson, who has worked closely on the project for Yorkshire Water, said: "The lining rig means that we can reline more than 200 metres of water pipe without having to dig a trench.

"A single hole is excavated at each end of the section of pipe to be lined and the machine does the rest.

"It scrapes out any sediment from inside the pipe and then places a new lining inside the pipe, leaving us with water pipes as good as new."

Yorkshire Water also used modelling technology to plan a way of working close to the busy Manchester Road without blocking lanes.

The project has seen the company build four huge storm storage tanks in the city, one under the Yorkshire Water car park in George Street.

The tanks hold back water which, following heavy rain, can be sent back into the sewerage system for treatment.

e-mail: will.kilner @bradford.newsquest.co.uk