Drainage systems play an essential role in conveying stormwater runoff to reduce
the risk of waterlogging and flooding. The drainage system in Permata 2 Housing
Estate, Talang Kelapa, Palembang City, has experienced reduced performance due
to channel sedimentation and backwater effects at several outfalls, limiting its
capacity to convey runoff efficiently. This study aims to evaluate the capacity of
the existing drainage system and develop a redesign using EPA SWMM 5.2.This
research employed a quantitative descriptive method with hydrological and
hydraulic approaches. The data consisted of maximum daily rainfall from 2016–
2025 obtained from the River Basin Agency (BBWS) and the South Sumatra
Meteorological, Climatological, and Geophysical Agency (BMKG). Rainfall
frequency analysis was performed using the Log Pearson Type III distribution in
Hydrognomon. The design rainfall was then converted into rainfall intensity using
the Mononobe method and arranged into a rainfall pattern using the Alternating
Block Method (ABM) before being used as input for EPA SWMM 5.2. The
simulation results identified 17 critical drainage channels that caused flooding at
eight junctions, with a maximum flood duration of 6.00 hours and a maximum flood
volume of 4.447 m³. The proposed redesign included combining all outfalls into a
single discharge point, adding connecting channels, and enlarging the dimensions
of the 17 critical channels. The redesigned simulation showed that all channels
operated safely, with Max/Full Flow values ranging from 0.01 to 0.60, and no
flooding occurred at any junction. This study provides a technical recommendation
for improving the performance of residential drainage systems and supports the
achievement of SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Cities
and Communities), and SDG 13 (Climate Action) by enhancing urban drainage
resilience to flooding.
Keywords: drainage, flooding, EPA SWMM 5.2, Hydrognomon, channel capacity,
redesign, SDGs.