Dams & Hydro

Dam Safety Evaluations and related analyses revealed a number of problems at Pongolapoort Dam, the most critical being an inadequate spillway capacity. To provide attenuation storage to compensate for the insufficient discharge facility, the dam has consequently been operated at a lower storage capacity over recent years.

In 2018, ARQ Consulting Engineers was appointed to carry out a full dam evaluation to determine what improvements can/should be made to, inter-alia, restore the dam to operation at Full Supply Level (FSL). The evaluation included:

• a Dam Safety Evaluation as required by South African Dam Safety Legislation;
• Flood hydrology determination to define the applicable flood peaks and volumes;
• Spillway capacity determination, evaluation of the total flood handling capacity of the dam through a comprehensive flood routing exercise;
• Geotechnical and geological review of the foundation rock mass
• Instrumentation review;
• and finite element analysis of the arch dam.

A clear delineation of the various rehabilitation requirements and a broad definition of the options in respect of the existing works was developed to facilitate and inform further phases of dam betterments.

Project details