BET you've never seen the water treatments works at Acomb Landing looking quite like they do in our gallery. But when were these photographs, which clearly show major building works going on, actually taken?

The treatment works were originally built in 1846, after the York New Waterworks Company had been set up by an Act of Parliament with the purpose of 'better supplying with water the city and neighbourhood of York'.

Before that, York's supply of clean water had been strictly limited. Lendal Tower had been used as a 'waterhouse and waterwork' since 1677, and the waterworks associated with it had been expanded in the 1780s. But they weren't up to the job of supplying water to an expanding city. "Only a limited supply of water was available from these early waterworks," reports the York volume of the History of the Country of York, edited by PM Tillott. "In the late 18th century each half of the city was supplied for only three days a week, although during raceweek and the assizes a daily supply was maintained."

Water was carried in pipes made from elm. "Until the early 19th century... the wooden pipes were frequently blocked by sediment from the unfiltrated water," notes the History of the County of York.

So the new, modern treatment works built at Acomb Landing in 1846 were badly needed.

The photographs in our gallery clearly show waterworks being built at Acomb Landing. Equally clearly, however, they don't date from 1846. So what do they show?

York Press:

Construction at Acomb Landing water treatment works. But what year?

According to the History of the County of York the treatment works were expanded several times in the second half of the Nineteenth century: in 1878, in 1886, and again in 1895, when the company was renamed the York Waterworks Company.

So the photographs might well date from that 1895 extension, which increased the capacity of the treatment works so that they could supply Earswick, Towthorpe, Huntington, Water Fulford and Bishopthorpe. They could also be later, because the treatment works were extended again several times over the following years as the demand for water increased. But the photographs record what appears to be a major building and construction project, so we suspect they were probably taken in 1895. The equipment worn by a diver (below), who was presumably helping with laying water pipes across the river, certainly seems very old-fashioned, and might confirm the 1895 date.

York Press:

A diver, who was presumably helping lay pipes across the river bed

We'd love to hear from any readers who tell us otherwise, however, or could give us more details about what the individual photographs show.

The photographs all come from the archives of the Yorkshire Architectural and York Archaeological Society, YAYAS, which celebrates its 175th birthday later this year.

YAYAS looks after several wonderful collections of historic photographs, including the Evelyn Collection, which was built up by the medical practitioner Dr William Evelyn who, in the early 1900s, became a leader campaigner for the preservation of York; and the Hanstock Collection, from the York commercial photographer William Hanstock, who died in 1942.

You can find out more about YAYAS, and the photographic collections it looks after, by visiting www.yayas.org.uk/