GeoGraph - photograph every grid square

With Thomas Telford acting as consultant engineer, canal engineer James Potter built the Knypersley dam. It took his men 5 months to dig down 29 feet to reach solid ground suitable to support the core of the dam. This was made of puddled clay, a process which creates a dense impervious mass. (This process was used to line the canals and is still in use today to create natural ponds and other water features.) Earth and more clay were banked up against this core creating the finished dam we see today. Although it was completed in 1827 the reservoir wasn't fully operational until 1829 due to settlement of the core resulting in cracked pipes.
Judgfield Farm is on the hill in the centre of the photograph.