Civil Engineering June 2021 | Vol 29 No 5

Q Q Construction of 3.20 km of small di- ameter collector piping between bore- holes and the existing Romanskolk header reservoir Q Q Construction of a 500 kℓ sectional steel storage reservoir at Brandvlei Q Q Construction of a gravity main pipe- line between Romanskolk wellfield and Brandvlei over a distance of 51.680 km through an elevation of 69 m Q Q Construction of a water treatment plant at Brandvlei, utilising activated alumina to remove excess fluoride, four pressure sand filters and a disin- fection facility Q Q Refurbishment of the high lift pump station at the Brandvlei Reservoir to lift the treated water from the existing storage reservoirs into the elevated storage tank Q Q Construction of a 22 kV medium voltage electrical power line over a distance of 60 km Q Q Telemetry system to monitor and control pumps and reservoir levels. The construction contract was awarded to Messer’s JVZ Construction for a total contract value of R104 749 686,71. Construction commenced on 1 June 2019 and was completed in October 2020. Since May 2020, the project has been producing sufficient good quality water for the community of Brandvlei. The groundwater levels of all the bore- holes are continuously managed and ab- straction rates are managed accordingly. Both the engineer and the hydrogeologist monitor the system’s data on a three- monthly basis and advise the Hantam Municipality on allowable abstraction. The following contractors were em- ployed on this contract: Q Q Civil works and lead contractor: JVZ Construction Q Q Mechanical works: Hidro-Tech Systems Q Q Electrical control & instrumentation: Woodrow Engineering Q Q Electrical: MV powerlines & trans- formers: EMC Reticulation Q Q Telemetry system: Spectrum Communications Q Q Engineer: BVi Consulting Engineers Q Q Hydrogeologists: GEOSS South Africa Q Q Environmental assessment & control: EnviroAfrica Q Q Project financing: Department of Water and Sanitation THE CALVINIA PROJECT Home to 9 680 people, the town of Calvinia is 420 km north of Cape Town on the R27 Regional Road between Vanrhynsdorp and Upington and lies at an altitude of 1 050 m above sea level. The town is 60 km northeast of Nieuwoudtville and 140 km south- southwest of Brandvlei. Calvinia is located south of the Hantam Mountains on the banks of the Oorlogskloof River and is the main town of the Hantam Municipality. The town has always been privileged to have both surface water and ground- water sources for its supply. The surface water is from the Karee Dam, which was constructed in the 1960s at the foot of the Hantam Mountains 5 km north of the town. The dam has an impoundment volume of 944 000 m 3 , but a 1-in-50-year yield of only 370 000 m 3 per annum. Calvinia is located on the divide be- tween the winter and summer rainfall regions and the inflow into the Karee Dam is highly dependent on sufficient winter rainfall. Typically, if the dam is filled up in the winter months, the water lasts until mid- summer, after which the groundwater sources are utilised. The town has seven boreholes located within the basin of the Oorlogskloof River. The Oorlogskloof River is a dry water course and only flows seasonally if there is significant rainfall. Calvinia’s population has increased significantly since the 1960s and the town has outgrown its existing water supply. In addition, the current drought has led Figure 6 Brandvlei Water Treatment Plant Civil Engineering June 2021 33 Figure 7 Karee Dam in February 2017