ASLA completes Welmoed Estate’s External Bulk Infrastructure

In 2019 the Western Cape Government’s Department of Human Settlements awarded the Welmoed Estate Development Project Phase 1A to ASLA Construction. Phase 1A of this Integrated Residential Development (IRDP) project in Eersterivier comprises the construction of bulk civil engineering services for the estate, supporting civil and electrical engineering services, as well as the construction of 1 348 BNG housing units. ASLA’s scope of works also included the construction of a Temporary Relocation Area (TRA) that would serve as interim homes for the informal occupants of the land and the approved beneficiaries.

Temporary Relocation Area (TRA)

ASLA’s contract encompassed the construction of Civil infrastructure services as well as the design, manufacture, supply, and installation of Temporary Housing Units in the Temporary Relocation Area (TRA) – comprising 292 housing units, that would be used for households in transition. The TRA was completed just before the December 2020 break and was built with the purpose of temporarily housing residents during both Phase 1 and Phase 2 of construction of the IRDP. “The intention is to move people who no longer farm on the occupied property, as well as other approved beneficiaries, to these houses,” explains ASLA contract manager Francois Jooste. “People would then move in and out of the TRA, as the construction and completion of the project proceeds.”

Construction of external bulk civil engineering services

Bulk Sewer and Water infrastructure

Most of the unseen and buried bulk infrastructure external to the estate footprint was constructed by the ASLA team, including:

  • A six-km long, steel reinforced HDPE bulk sewer pipeline (varying in diameter from 350mm to 800mm) including pipe jacking under major access routes and associated manholes.
  • A 15ML reservoir with associated earthworks, landscaping, and roadworks with the concrete works on the reservoir undertaken by Exeo Khokela Civil Engineering Construction, under a subcontract to ASLA Construction.
  • A 420m stormwater line to prevent erosion of the steep topography by draining the reservoir’s stormwater into the nearby Jacobsdal Farm dam.
  • A 500mm dia PVC-O bulk water supply line and a 700mm dia PVC-O distribution pipeline, supply and feed from the reservoir.
  • Associated valve chamber works for both pipelines.
  • Some components were procured internationally and imported for the project.

“Often evidence of critically important bulk infrastructure is only seen by those of us who know what to look for above ground,” says Francois. “For example, the valve chambers are the only visible evidence of months of long hard work for the construction team. All the pipework is buried under metres of soil and all that remains to be seen, are these immaculate structures filled with pipes and fittings such as Tee’s, Valves, Meters, and Strainers – all working in concert to provide a functional end product.”

Transport infrastructure

The external bulk works included the construction of a double lane entrance road, intersections, and associated street and traffic lights, as well as pedestrian walkways on either side of Van Riebeeck Road. Two bridges were constructed to provide access to the planned residential area. “We demolished the existing retention dam overflow where one of the new bridges now stands, and constructed pristine concrete reinforced overflows, alongside the structure, packed with gabions to seamlessly blend in with the new bridge and existing wetland-like retention pond,” explains Francois.

Construction of internal services

The internal services of Phase 1A encompass the civil and electrical engineering services which are still outstanding include:

  • Site clearance
  • Services installation, including:
    • sewer mainlines & house connections,
    • water mainlines & house connections,
    • stormwater,
    • electrical sleeves,
    • irrigation sleeves, and
    • fibre sleeves.
  • Paving of roads and sidewalks

Energy infrastructure

Adenco Construction, that was contracted to install the Bulk Electrical infrastructure component of the project for the Western Cape Government at the Welmoed Estate, subcontracted the civil portion of its contract to ASLA Construction. “Our civil infrastructure scope at the newly constructed Penhill Substation included access roads, sewerage and stormwater systems with concrete underground structures that serve as septic tanks and oil separators,” says Francois. “We also constructed 12 pylons to support the new 66kV turn-in line – with nine of these constructed by means of excavation and stabilised backfill. The remaining three have concrete foundations.”

Fairbrother Geotechnical undertook the piling for two of the concrete foundations for ASLA, to a depth of eight metres. The final foundation was installed on a 40 m3 reinforced concrete base including 5 tonnes of reinforcing steel.

ASLA has also been contracted for the civil works associated with the three Welmoed switching stations within the project, as well as the planned pylons for the 132kV turn-in line to the Welmoed Sub-station for Adenco.

“Our client is very happy with the quality of the infrastructure that we have completed and handed over thus far,” says Francois, “We hope to have access to more of the internal footprint of the site soon, so that we are able to continue with the construction of roads, installation of services, and of course make progress towards the ultimate goal of the project, which is to build 1 348 homes for the qualifying  prospective home owners.”

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Posted on

July 12, 2024