When St. Cuthbert’s Swallet was discovered, the two large streams entering the cave flowed in routes extensively altered by the lead mining industry, and susceptible to change. The sink of the larger stream moved by 50 m around 1970 and about 20 years later the route of this stream changed completely, joining the second stream about 160 m from the Main Stream Sink. The distribution of the streams changed, the Entrance Pitch is now considerably wetter than previously, and the characteristics of Plantation Inlet Stream have changed considerably. Distribution changes between the Soakaway Sink and Pulpit Passage are described. As a result of the major stream change the chemical characteristics of water at the major sinks and many of the inlets in the cave have changed significantly. Minor inlets and the problem of water flowing from The Lake are considered.