The Challenge
A mixed-use development in Abuja included two basement levels excavated below the seasonal water table, requiring reliable drainage behind retaining walls to prevent hydrostatic pressure build-up and water ingress into finished basement spaces.
Our Solution
A drainage geocomposite was installed against the full height of the retaining wall structure, channelling groundwater down to a perimeter drainage collector connected to the building's sump pump system, replacing the thicker granular drainage blanket specified in the original design.
The Outcome
The drainage retrofit reduced the excavation width required behind the retaining walls by 300 mm per side, and the basement levels have remained dry through two full rainy seasons since handover.