Question NW859 to the Minister of Human Settlements, Water and Sanitation
22 October 2019 - NW859
Graham, Ms SJ to ask the Minister of Human Settlements, Water and Sanitation
Whether her department has put any plans in place to repair the wall in the Nqweba Dam, Graaff-Reinet, as per the agreement concluded with the former Camdeboo Local Municipality; if not, what is the position in this regard; if so, (a) what are the details of the (i) plans and (ii) time frames for the repairs and (b) will the dam be returned to the Dr Beyers Naudé Local Municipality once repairs have been completed?
Reply:
The Nqweba Dam, formerly known as the Van Ryneveld’s Pass Dam, near Graaff- Reinet in the Eastern Cape is used for municipal water supply to the town of Graaff-Reinet in the Dr. Beyers Naude Local Municipality.
The dam was designed by the Department for Irrigation and was constructed between 1921 and 1925 for the Van Ryneveldspas Irrigation Board. It is a concrete gravity dam with a maximum wall height of 46 m and a capacity of 46 million m3. Ownership was transferred to the Camdeboo Local Municipality in 2002.
Dam Safety Inspection Reports found the structure to be unstable under Recommended Design Flood conditions. This shortcoming is typical of concrete gravity dams designed at a time when flood estimates were based on inadequate hydrological records and when uplift forces in concrete gravity dams were not fully understood. A possible dam-break flood caused by a failure of the dam wall would cause a high loss of life and a large amount of damage.
Following studies which were conducted on the best way to proceed with the rehabilitation of the dam, there was an impasse on the recommendations due to a dispute on the different conclusions reached by the experts. One report indicated that the dam does meet the required factors of safety. The Dam Safety Office, which acts as a Regulator within my department, requested that an independent expert be appointed to carry out a dam safety evaluation of the dam and to review the analysis done in the first report. However, due to budgetary constraints, the DWS was not able to carry out the review as requested at the time. I have since instructed the department to find a budget for this review from the current baseline and reprioritise the existing budget.
To resolve this impasse, I have instructed my Department to procure the services of an approved professional independent person/company with dam safety expertise so that the required rehabilitation of Nqweba Dam can commence in earnest.