A vital restoration project has begun at Winchester's City Mill.

The wooden waterwheel, powered by the Itchen to mill flour, is being replaced after 12 years of use.

Dating to medieval times, the mill itself was restored to working order in 1743 and remained in use until the turn of the 20th century. In recent years, the mill was fully restored and is now a popular tourist attraction as well as a youth hostel.

The project, funded by National Trust legacies to the tune of £18,000, was started in January by two restoration experts from Itchen Abbas.

Ian Clark, a millwright approved by The Society for the Protection of Ancient Buildings, is in charge of producing the final construction, which means making three large rings of wood from scratch. Working from technical drawings of the original, he and his partner, Adrian Thompson, employed traditional techniques to manufacture each section from solid oak.

The job will take a total of two and a half months, with around 600 pieces of timber being fitted together, to form the new wheel, 1.7metres wide and 2.3metres in diameter.

The old wheel has been taken to Mottisfont Abbey to be put in storage for future exhibitions.

Bob Goodwin, who runs the mill for the National Trust, says he's delighted with the progress: "With the quality of Ian's workmanship, this waterwheel should last a lot longer. He's doing an excellent job and we should have no trouble in being ready to take visitors on the first weekend of March."

After 25 years of engineering and heritage conservation work, Ian laments the fact that rivers are no longer being used as much as they were.

"The wheel works a lot harder than originally because the river is higher up, due to a build-up of silt," he said.

"There aren't enough people managing our rivers anymore and it's a great shame because it's a completely clean and reusable source of energy."

Winchester's is one of the few remaining wooden waterwheels in the country. Most were rebuilt in Victorian times using metal. When fully operational, it mills flour every fortnight and there are regular tours for visitors.

"We can't produce the flour fast enough, people round here just love it," said Bob.