A liquid run-off disposal system 100 comprising an elongate tank structure having one or more culvert sections 102 adapted to be arranged end to end in a substantially horizontal orientation below ground. Each culvert section 102 also includes a plurality of louvre-shaped inserts 114 provided in the sidewalls thereof wherein, in use, when liquid run-off is piped into the culvert section 102 it can drain away by soaking into the surrounding soil.