A drainage system for connecting a rack drain on a mobile plant rack to astationary building drain, wherein the plant rack is operable to slide betweenfirst and second positions wherein the building drain is proximate and distalthereto, respectively. The drainage system comprises at least one horizontalsupport proximate to the bottom of the mobile plant rack and a flexibleconduitfluidically connected to the discharge end of the rack drain, extendingarcuatelybetween a receiving end fixed within the interior rack space and a dischargeend fixed outside of the interior rack space, wherein the discharge end isfluidically connected to the stationary building drain. The receiving end oftheflexible conduit is raised above the discharge end and the flexible conduit issupported by the at least one horizontal support to maintain a generally downslope grade.
