Abstract

Flooding in Indonesia, caused by factors such as heavy rainfall and poor drainage systems, causes major losses in both infrastructure and loss of life, while submerged underpasses in major cities during the rainy season can disrupt traffic flow. This research aims to plan a model for handling floods in toll road underpasses. The methods used are location surveys and hydrological analysis. The results of this research showed that the catchment area was 0.2 Ha with an intensity of rain/rainfall at the 2 years return period of 114.19 mm/day and 223.85 mm/day at the 100 years return period, the planned flood discharge was 0.07 - 0.14 m³/second, and uses a 100 liter/second pump. The conclusion of this research, for the hydrological aspect, is that the planned flood discharge is 0.11 m³/second at a return period of 10 years, and the runoff associated with a pump capacity of around 100 liters/second and a storage capacity of 2,000 m³ in the polder system. Based on hydrological analysis, micro polders can overcome the problem of puddles within a certain period of time.