EARLIER this summer we reported that Lendal Tower had been sold for about £1 million to property development company the Helmsley Group.

This surprised many in the city who were unaware that the historic building could be bought and sold like ordinary properties.

Once a key part of York's defences, and for centuries the hub of our city's water supplies, Lendal Tower ended up in the hands of Yorkshire Water's sister company Keyland Developments.

In July it sold the 14th century site to the Helmsley Group, based in Pocklington.

Bosses said they were going to meet York planners, the Museums Trust, English Heritage and the Environment Agency to consider how Lendal Tower could be sympathetically developed into homes, with possibly a restaurant and other facilities attached.

It remains to be seen how compatible these plans are with a building which is both Grade I listed and a Scheduled Ancient Monument.

The earliest remaining written reference to Lendal Tower dates from 1315, and the Royal Commission On Historical Monuments says it was probably built soon after 1300.

Inside was kept the iron chain which used to be cast across the Ouse to the Barker Tower on the opposite bank every night, to stop boats entering the city without paying the toll.

Bulwarks were added at both posterns by order of the Lord Lieutenant in 1569 to protect against attack by the rebel Earls of Northbumberland and Westmorland. A tiled roof was added in 1598.

But it was in the 17th century that Lendal Tower's role changed from defender to provider.

Attempts to operate a piped water supply for York from the tower were undertaken by a Mr Maltby between 1616 and 1632.

In 1631 the city agreed to take a fourth share in the enterprise, and the tower became known as "the waterhouse".

Later the city's share was leased to Thomas Hewley and he was instructed to remove the wooden water pipes from Ouse Bridge. By the middle of the 1600s engravings depict the tower as three storeys high but dilapidated.

Then in 1674, Henry Whistler of London proposed a new scheme for supplying water.

Impressed, the council leased him the tower for 500 years on April 1 1677 at a peppercorn rent. He was granted permission to install engines and dig up the ground to lay pipes.

"The tower was enlarged and heightened to take a lead cistern to which water was at first pumped by a waterwheel in the Ouse," relates the Inventory Of The Historical Monuments In The City Of York.

"This worked so erratically that in 1684 it was replaced by a 'wheel wrought with horses, within the tower'."

After Whistler died the concern was sold to Col William Thornton of Cattal and later mortgaged to a Derby man, possibly to pay for a new steam engine.

In the third quarter of the 18th century Lendal Hill House was built against the side of Lendal Tower.

Col Thornton established York's first heated baths there.

There was one room for hot and tepid baths and another for cold bathing, both with dressing rooms.

York Waterworks was sold to Jerome Dring in 1779 for £7,000. Most of the 28 shares were held by him and John Smeaton.

Graham Wilford worked for York Waterworks for 27 years, and was managing director for the ten years prior to its being taken over by Yorkshire Water in 1999.

He is an expert on the company's history, and described John Smeaton, designer of the famous Eddystone Lighthouse, as a "brilliant man".

"He coined the phrase 'civil engineering', as opposed to military engineering. He is known as the father of civil engineering," said Graham.

"He was involved with the improvement of the steam engine at the waterworks."

Smeaton's work enabled the engine to produce 18 horsepower, raising 18 gallons of water at a stroke, or 10,500 an hour.

It toiled away in Lendal Tower from the 1780s until 1836, when it was moved to the purpose-built engine house. A decade later the New York Waterworks Company was incorporated, buying the shares for £20,000. The works themselves were moved to Acomb Landing.

York then boasted "the second set of slow sand filters in the country after Chelsea," Graham revealed.

"They proved to be very efficient, but microbiology wasn't understood at the time they were installed" - so no one knew quite why.

Lendal Tower's tank was removed, lowering it by 10ft, and railway architect George Townsend Andrews redesigned the top to give it a medieval, crenellated look. York Waterworks retained the tower as a store and offices.

When Lendal Bridge was built in 1863, the company was awarded £240 in compensation after its uninterrupted view of the river down to Ouse Bridge was obliterated. Graham has happy memories of the panelled boardroom at the top of the tower, and its still-impressive views over the river.

Every year on All Saints Day he would host a dinner for the Lord Mayor and other civic dignitaries and ceremonially pay the peppercorn rent. He is pleased that it may soon be in use again.

"Lendal Tower is a beautiful building. It really has a very significant place in the history of York's piped water supply.

"That ended in 1999. It would be lovely to see the tower and the side building in use for the future."

York conservationist Alison Sinclair also wants greater use of the site, but she is concerned at its sale to a property developer. She notes that the lease has some time to run but asks "does that give the most recent leaseholder the right to sell the building off to a private developer now it has been made surplus to requirements?"

For its part, City of York Council confirmed it holds the freehold of the property and said that the present tenant's lease runs out in 2177.

"The lease, signed in 1677, allows the tenant to transfer the property to another party," a spokeswoman said. "However, as this is a very historic building, the council wants to agree with the new tenant an acceptable and sustainable use to preserve the building.

"Any plans for its future would require Scheduled Monument Consent, which

would have to go to the Secretary of State for determination."

Alison has another proposal for Lendal Tower.

"I really want to see if the tower can be returned to the city for use as part of the City Walls Access and Interpretation Plan.

"This is something for which the city has been given funding from Yorkshire Forward and aims to improve access both physically and intellectually to the City Walls.

"A plan is presently in preparation for doing this, the aims being: 'to create access for all; to improve the presentation and interpretation facilities; to create an educational resource for schools and colleges; to secure the long-term integrity of the Walls'.

"Along with its ancillary buildings and the garden they enclose, the tower could be transformed into a Visitor Centre and educational facility for the City Walls access plan. It would be difficult to find a more acceptable and sustainable use for it."

Updated: 09:22 Monday, August 16, 2004