In July 2014 the construction of the second underground reservoir on Grimstone Down was completed.
Photo - Colin Jackson
With assistance from George Keast at Wessex Water here are a few facts and figures about the new installation. A detailed archaeological survey was carried out before construction began revealing evidence of Iron Age activity. Pottery, flints and animal bones approximately 2,000 – 2,500 years old were found.
Photo - Wessex Water
The new reservoir is a service reservoir capable of holding two megalitres – that’s 2,000,000 litres. It is part of the East-West water supply link in Dorset and provides local storage to about 1,000 Wessex Water customers. The construction was carried out in order to more than double the site storage capacity. Maintenance work was also carried out to the existing reservoir and the on-site security was updated. The installation of the new reservoir cost £1.7 million.
Photo - Colin Jackson
Photo - Colin Jackson
On Thursday 21st May 2015 Richard McConnell of Context One Archaeological Services Ltd was the guest speaker at the Stratton History Group meeting. He gave an entertaining, illustrated, informative talk on the archaeological excavation that took place before the second Grimstone reservoir was constructed for Wessex Water, in language that everyone could understand.

He began with a view of the wider scheduled site at Grimstone Down – a protected area of national importance – describing physical features from the Iron Age and Romano-British periods; and a few earlier Bronze Age Round Barrows too.

Diagrams and photographs were shown to make understanding the complex field system of Grimstone Down that much easier. Aerial photographs from 1947 – just prior to the construction of the first reservoir in 1950 – helped make sense of the lumps and bumps of the countryside.

To the south of the area, a circular anomaly - thought to be a ceremonial site - was detected with entrances to the east and west.

Within the plot of land decided upon as the site of the second reservoir, everything of interest to the archaeologist was within half a metre of the surface.

The largest finds were evidence of a 30 feet diameter roundhouse with a central hearth and a possible entrance porch on the south-east side, and an enclosure ditch forming a boundary.

Kilns with flues were also found, of a size suggesting that localised re-working of previously constructed metal implements was carried out.

In all, 75 features were found on the second reservoir site including post-holes and storage pits. Pottery remnants were found – very useful in pin-pointing the date of habitation of the site. Most were pieces of mid-Iron Age domestic-ware; not of high status. Animal bone – cattle, goat, sheep, pig and a small amount of horse - was evident. Some rather odd chalk discs were found too. Each had a central hole and their purpose is a matter of discussion.

Early in 2016 the publication of an article in the 'Proceedings of the Dorset Natural History and Archaeology Society' will detail the precise results of the excavation.

Information about Context One Archaeological Services is available HERE

A document produced by Wessex Archaeology in September 2008 can be found HERE