The adit was directly connected to Beech Pit and features an underwater connection to the nearby Westbury Brook Iron Mine.

originally driven as a drainage level for Beech Pit (qv), with the aim of intercepting spring water that naturally flowed from the junction of the sandstone and limestone strata—water that would otherwise have entered and flooded the mine workings. Constructed to a length of 420 yards, the adit successfully reduced the inflow of water into the pit.

In the early 20th century, the adit was repurposed as a water supply source. It later served as an emergency supply, though this use was discontinued relatively recently.

Pearce notes:

Beech Pit was sunk by Messers Henry Crawshay & Co in 1843 as an iron mine. It had 4 levels and was closed in 1893. A drainage level was dug in c1876 to level No 3 as a water supply. p 26 adit inspected by miners in 1903 and again by Roy Wright of Clearwell Caves and G W Hudson in 1980. A shaft 40 yards deep was dug in 1907 to provide extra water.

Note: November 1996:

Adit blocked with concrete cover. Do not attempt round trip.