A drainage system (1300) comprising a cap (1302) having one or more sidewalls defining a recess (1326) and a body (1304). The body (1304) comprises an inlet at a first end (1312) of the body (1304), receivable within the recess (1326) of the cap (1302), an outlet at a second end (1384) of the body (1304), and a passage (1310) to allow fluid flow from the inlet to the outlet. The system (1300) further comprises a spacer arrangement (1306) to space the body (1304) from the cap (1302) when the inlet is received in the recess (1326) of the cap (1302), so as to form a channel to allow fluid flow to the inlet between an outer surface of the body (1304) and an inner surface of the cap (1302).