Aqueduct (ditch E3). Excavation of this feature totalled rather over half its observed length of 80 yards. Throughout, its profile and dimensions remained almost constant: width at top, average 5ft., splayed to 7ft at West end; at bottom, 2ft 6". throughout; depth, almost exactly 9ft from ancient surface throughout. The sides, somewhat splayed above where cut through loam and gravel, are lower down, where cut through the stiff London Clay, always within 5-10 degrees of vertical. The bottom was invariably flat and sharply squared, and with no primary silt upon it. The whole must have therefore been lined, presumably with timber, and probably covered over, but no trace of lining was found. Its explanation as an aqueduct 'is confirmed by these further facts: at the upper excavated end and nearest to Sheepen Springs, water flowed in so fast that a pump had to be kept continually at work to clear it'. The aqueduct may have been a short term water management system that was in use from the establishment of Roman occupation until the foundation of the Colonia and the formation of a more comprehensive water management system.<1>

During excavations at Sheepen in 1970 (ECC488) a trench was opened to ascertain the relationship between the Sheepen dyke and the aqueduct. This confirmed that the aqueduct cut through the filled-in Sheepen Dyke. The 'aqueduct' was seen as a 1.2m wide slot filled with grey clay which cut across the fill of the ditch. The excavator raised some doubt over its function as an aqueduct.<2>