A water-resistant busway with a water drainage duct of the present invention (10) comprises a joint assembly (12) arranged between the ends of first and second busway housings (14, 16). Joint assembly (12) includes a water-resistant cover (30) releasably attached to first and second housings (14, 16) by cover fastening devices (32, 34). Water-resistant cover (30) includes an access hole (36) disposed therein, with access hole (36) receiving a complementary access hole plug (38). Housing spacers (22, 24, 26, 28) each include a water drainage duct (118) disposed therein to drain water from above the water barrier (104) and web (46) of upper piece (42) of housing (14) to below the water barrier and web (46) of the lower piece (44) of housing (14).