IT is almost nine years since Sarah McLeod answered an advertisement for an administrative assistant working for the Arkwright Society at Cromford Mills.

She applied for the post because she had just gone through a divorce, had two young children, one a severely autistic son, and wanted a stress-free job with no responsibility.

Less than a decade on, Sarah is now chief executive of the Arkwright Society, is responsible for the day-to-day running of the hugely important Cromford Mills and is the driving force behind a £20 million scheme to redevelop the World Heritage Site as a major tourist attraction, catering for more than 200,000 visitors a year.

"So much for a stress-free job," said the dynamic 44-year-old.

"I wasn't intending to get so involved but when I first walked on to the site, it just blew me away. I thought 'Wow, what an amazing place'."

Londoner Sarah had seen the mills from a distance as a teenager when her mother had moved to the area for 10 years.

"I used to play sport on the meadows next door," she said. But in those days, I was interested in boys, not history, so I didn't really take much notice of the mills."

University and a sandwich-course degree in business and finance took her away to the north-east, working for Shell.

"I was 19 and had to sell bulk fuel to northern hauliers. That taught me how to handle myself. I became a tough cookie," she laughed.

By the time she finished university, she admits she was "pretty good at marketing".

It was not long before she set up her own freelance marketing and PR company in London, followed by an environmental agency, which set up educational nature projects for school groups on petrochemical sites.

"After that, I bought a restaurant and hotel business with my husband in Oxfordshire, which we ran for six years until we divorced."

It was all experience which was to become invaluable in her new role.

Sarah's decision to return to the Cromford area was based on her own memories of a safe and happy childhood.

She said: "I was living in a tiny flat in Westminster. My six-year-old son, Sylvester, was autistic and there was no provision in the area for him so he was being self-educated at home. I also had a seven-year-old daughter, Jaybird. It was hard.

"I loved the Derwent Valley so, when I saw the ad for the job at the mills, I decided to give it a whirl.

"As soon as I arrived, I discovered the Holbrook Centre for Autism, which turned out to be one of the best in the country. Henry Winkler, the Fonz in Happy Days, was profoundly dyslectic and set up an educational trust fund.

"Last year it was awarded to the best special schools in the country and Holbrook got second place.

"They used the £10,000 prize money to give non-verbal children iPods. Sylvester is 16 and has never spoken but now he can go into a shop and via the iPod can say 'Hi, I'd like some biscuits'. It has completely changed his life and mine. The only drawback is the voice is American!"

Sylvester stays at the college one night a week and Sarah has incredible support from the Derbyshire Autistic Support Group.

Jaybird, now 17, is a day girl at Denstone College, Uttoxeter, doing her A-levels.

It means the hyperactive Sarah has time to dedicate herself totally to the task in hand.

"This site is so important. It is the world's first water-powered mill," she said. "When I arrived, the site had just been given World Heritage Site status but it was in a poor state of repair.

"The Arkwright Society was formed in 1979 with the express purpose of restoring the mill and promoting the educational aspects of the industrial revolution.

"The members were all volunteers and they did an amazing job, saving the mill from demolition and getting the site listed.

"The site was 100% better than when they took over but, to me, it was still a mess.

"Half the buildings were in use as a cafe, shop, offices, small business premises and a conference room. But the three largest buildings were still out of use, including the most important – the mill."

The site had received a Lottery grant to carry out emergency repairs and outwardly, the buildings looked good.

"But the grant was a double-edged sword," said Sarah. "Because the buildings looked okay from the outside, we lost the sympathy vote when it came to other funding."

Sarah's initial job was to work with a team to seek grants. Her enthusiasm and drive led to her rapid promotion to visitor services manager overseeing conferences, functions and tour guides.

Over the next seven years, she moved on to become assistant director, deputy director and ultimately chief executive.

"The first thing I did was have a massive clean-up. There was so much rubbish on the site. We literally took away 23 old dumped fridges."

Having created a pleasant walled space, Sarah applied for an alcohol licence – despite some entrenched opposition – and encouraged groups such as re-enactment societies to perform.

"I also had interpretation boards put around the site because there was nothing to explain what anything was or its history.

"I introduced a pocket mill guide and built up a really good tour guide team. We can now offer tours every day of the year except Christmas Day."

She set up a training programme for staff, introduced a pay and display car park to generate income and set about restructuring the whole organisation to bring it into the 21st century.

"It costs £1 million a year to run this site, which is quite a big business, but it had always been run by enthusiastic volunteers who were interested in the history of the mill rather than generating cash to preserve it. They didn't even have a website."

What emerged from this whirlwind of change was a £20 million master plan for the site, which is to take place in five phases over the next 10 years.

"I've been working on it for the past 18 months with architects, surveyors, tourism experts," said Sarah. "My aim is to turn Cromford Mills into a top-class tourist destination linked to the other sites in the Derwent Valley."

The big issue for Sarah and the Arkwright Society trustees was the order of development.

"I felt it was no use developing the mill itself and then having no facilities in place for visitors," she said.

So Phase 1a will be the creation of an impressive interactive gateway information centre in a large warehouse building.

"We've commissioned a huge scale model of the whole Derwent Valley World Heritage Site, from Matlock to Derby," said Sarah, bubbling with enthusiasm. "It will show the water, the topography, the amazing tors, the villages. There will be interactive buttons which people can press for information about what they can see and do, the history of the various sites and so on.

"People will be able to buy tickets for all the sites in the valley. We may introduce a passport scheme giving access to all the sites.

"We're also going to introduce a heritage shuttle service, so that people can get a train from Derby to Cromford, then hop on the shuttle bus which will allow them to get on and off at whichever site they want to visit.

"We're also working on getting the Cromford canal operational, so that people can get on a boat at Cromford and drop off, say, at Masson Mills."

The first phase will also include the creation of a viewing platform inside Arkwright's historic mill, though at present the view is of piles of rubble.

"It will allow people to see the challenge in terms of what we have to do to the building," said Sarah.

The actual restoration of the mill will not take place until almost everything else is in place.

First a huge new restaurant will be created on the ground floor of one of the buildings with function rooms and conference facilities above. A brand new kitchen will be built and a farm and deli shop, on the lines of Chatsworth, established, while 70 new business units for start-up creative industries like IT and the media will be created.

Across the road, beside the canal, another building will be converted into an education centre for use by schools and other groups.

Phase Two will involve the development of a canalside restaurant, the creation of artists' studios, more shops and holiday lets in the former mill manager's house.

Phase Three is the restoration of Arkwright's mill itself.

"We obviously need to tell the story of the mill and we are looking for the best in the world to interpret it," said Sarah. "At the moment it is a blank canvas and incredibly exciting. Some people want to restore it to how it looked with all the machinery in place; others want to preserve the archaeology; some want to make it a museum.

"There is only one Arkwright machine in this country at Helmshore in Lancashire. There is a modern replica, which was built by an Ashbourne man for the Cromford mill in Germany, established there as a result of industrial espionage."

Phase Four of the plan will involve the upgrading of the upper floors of the Gothic warehouse for use as workshops and craft units or possibly overnight accommodation if the number of visitors rises as expected.

"It's all subject to planning permission and grants but we've already secured £2m from the Heritage Lottery Fund and we've put in a large bid to the European Regional Development Fund, as well as smaller bids," said Sarah.

"I'm confident that Phase One will be under way in the autumn and should be completed in 18 months to two years.

"As soon as that starts, we'll start applying for funding for the next phase."

The scheme is estimated to take 10 years to complete. Sarah doubts she will be still be in her current role by then.

"I would like to see through the first two phases," she said. "The First Mill project will be a fantastic job for a new chief executive. If I stay for another five years, I will have been here 13 years, which is long enough. I don't believe in staying forever."

In the meantime, Sarah and her team are involved in the daily running of the site and its events programme, ranging from theatrical performances and antique evaluation days to painting exhibitions and tours of nearby heritage sites.

Sarah said: "I work from 8.30am to 5pm most days. When Sylvester is not home, I might stay until 9pm or 10pm. We do a lot of evening meetings because many of our volunteers work full-time. I try to be flexible both with my staff and myself.

"I think what we are doing here proves anything is possible if you believe in it and are prepared to work for it.

"This site is a little gem. I can't wait to see all our plans come to fruition."