Between 1st and 3rd of April 1996 the Cambridge Archaeological Unit undertook a watching brief of excavated trenches outside the South Porch and Song School of Ely Cathedral. The work was part of an on-going programme of drainage improvements to the south side of the cathedral. The trench ran approximately three metres to the south of the north ambulatory of the cloisters, parallel to the window wall. Three short connecting trenches joined the main trench to the outfall of the rainwater down pipes from the South Porch/Song School roof. The drainage system will run into the system already installed in the north west corner of the cloisters.