Case study: Design and operation of sustainable urban infiltration ponds treating storm runoff

Combined wetlands and infiltration ponds are cost-effective 'end of pipe' drainage solutions that can be applied for local source control as part of urban development and regeneration. The aims of this case study were to assess constraints associated with the planning, design, and operation of these ponds, the influence of aquatic plants on infiltration rates, and the water treatment potential. Storm runoff was first stored and treated in a constructed wetland before it overflowed into parallel infiltration ponds of which one was planted and the other one was unplanted. Three international best management practice design guidelines failed in practice. The presence of macrophytes in one infiltration pond had no significant influence on the drainage properties. The water quality of both ponds was not acceptable for water reuse directly after the system setup. Filamentous green algae within the unplanted pond were blooming in spring and summer creating an aesthetically unpleasing pond surface area. After 1year of operation, barley straw and Carassius auratus (common goldfish) were introduced successfully to control the growth of algae.