Upper Flood Swallet

Upper Flood Swallet is a major Mendip caving system that exceeds 4km in length and is renowned as one of the most beautifully decorated caves in the Mendip Hills. Its entrance was washed open by the great flood of July 1968, initiating a long and arduous dig that culminated in a major breakthrough in 2006. The many hours of effort were rewarded when an opening in a boulder choke revealed a magnificent chamber, a major streamway, and numerous interesting passages. That same year, a particularly beautiful section named Neverland was also discovered, containing a stunning array of pristine formations.

The cave is mostly a classic vadose streamway, which can be followed for most of the cave’s length. From the entrance shaft’s ladder, a short set of man-made steps, take you to a widened series of stoops and crawls, sometimes following a small stream. After several hundred metres the passage lowers to a crawl before opening out again. The streamway, fed by various inlets then continues, with several sections of crawling, a short canal section and occasionally, some walking, until the Boulder Choke is reached. From here, a number of squeezes, some now enlarged from their original very tight dimensions, must be negotiated before emerging into the Departure Lounge chamber. The streamway after, reaches much more impressive dimensions with a ceiling in places of up to 20m. This is followed for a few hundred metres before an obvious incline leaves the water behind to climb up into Royal Icing Junction. Here the cave splits and routes can be followed south, east and west. Off of west passage is the stunning Neverland, where caving kit must be removed and extra care taken on any visit to see the impressive and varied formations within.

History of Exploration

The Discovery

Following the initial opening of the entrance in 1968, exploration of Upper Flood Swallet was characterized by decades of determined, incremental progress. Joint digging efforts by the Mendip Caving Group (MCG) and the Reservoir Hole team led to a breakthrough in 1972, revealing decorated passages before progress was halted again. After a pause in the late 1970s, work resumed, and by 1987, cavers had pushed through difficult sections like the Lavatory Trap and Sludge Duck to discover the Black Shale Rift and the Red Room. By the 1990s, however, all leads seemed exhausted, and there was even a failed attempt to create a second, stable and easier entrance in 1995.

The Big Breakthrough

The major breakthrough occurred in late 2006 when a route was forced through a boulder choke, revealing a kilometre of new passage in a single trip. This led to the discovery of the impressive Blackmoor Streamway. At the end of 2006, a further significant discovery was made when a climb up into a higher-level fossil passage, ‘Royal Icing Junction’, led into a network of passages, heading off in all directions. From West Passage, the beautiful Neverland was discovered. Over the following years, further finds, meant that the cave surpassed the 4km mark, a major milestone in Mendip caving history.

Access

The entrance to Upper Flood Swallet is locked. Access is controlled by the Mendip Caving Group. Please contact the MCG via the Upper Flood trips page to arrange a trip.

Upper Flood Wardens

Due to the very delicate formations throughout the cave, all Upper Flood Trips are led by wardens. To learn about the warden system, find out who the current wardens are, or to become a warden, please visit the warden page.