The Challenge
Significant seepage losses through the existing earth dam face and unlined reservoir floor were reducing the storage capacity available for downstream irrigation and community water supply, and were causing progressive erosion of the dam embankment during the wet season.
Our Solution
Willem Olaf designed and supplied an HDPE geomembrane liner system covering the upstream dam face and reservoir floor, installed over a non-woven geotextile cushion layer to protect the membrane from the irregular earthen substrate and accommodate minor settlement. All seam welds were carried out on site by trained installers and tested by air-lance and vacuum-box methods.
The Outcome
Reservoir storage losses were substantially reduced, restoring the dam to its design storage capacity and extending dry-season water availability for dependent farming communities. The lining system was designed to withstand the thermal cycling and UV exposure conditions typical of the Nigerian climate for a minimum 20-year service life.