High Bullough Reservoir is the oldest of all the reservoirs in the Rivington chain, having been authorised by the Chorley Waterworks Act 1846 and completed in 1850. It was built for Chorley Waterworks by the engineer John Frederick Bateman, who had estimated the cost of the project while working for Edwin Chadwick's Towns Improvement Company, and had then acted as Engineer for the project. The outlet consisted of a pipe running through the dam, and supported by two masonry piers where it ran through the central clay puddle. The outlet valve was at the downstream end of the dam, and although this configuration is no longer thought to be good practice, there have been no serious issues with the reservoir throughout its operational life. The earth dam had a maximum height of 39 feet (12 m), was 988 feet (301 m) long and impounded 55 million imperial gallons (250 Ml) of water.