A reconfigurable barrier system (10) includes a plurality of support units (100) spaced one from the other, with each support unit (100) having at least one engagement section (110) defining an elongate channel (112). System (10) further includes at least one retention unit (200) that is substantially impervious to liquid, and is supported to extend between a pair of support units (100). Each retention unit (200) is formed with a pair of opposed engagement portions (212) which slidably engage respective ones of the support unit channels (112). Each retention unit (200) is also formed with a seal portion (220) that extends along a longitudinal edge of at least an intermediate portion (214) between the engagement portions (212). A barrier section (15) is defined by each pair of support units (100) and the at least one retention unit (200) supported thereby.