Consulting engineering firm Gibb has been awarded the civil engineering contract for the third phase of Cape Town’s Joe Slovo housing development project.

The scope of work includes design, obtaining approvals for design, as well as supervising construction activities.

The project, which was launched after a devastating fire in 2005, forms part of the larger N2 Gateway project, which is a collaboration between the provincial government and the national Department of Housing, and aims to transform the area’s informal settlements into a low-cost housing development while keeping the relocation of residents to a minimum.

“To achieve this, the housing units are double-storey single units, which deliver higher densities of dwelling units per hectare,” says Gibb lead engineer Gareth Jansen.

The housing units are 40 m2 and consist of two bedrooms, a bathroom, a kitchen sink, ceilings and plastered and painted walls on the inside and outside.

Phase 3 is further divided into three stages, namely A, B and C. Phase 3A, which comprises 1 131 units is partially complete with 588 houses built, while Phase 3B, which comprises 929 units is currently undergoing approval processes. Phase 3C’s construction will start shortly.

“This project is the first of its kind. Owing to the high-density nature of the layout, we had to create more units per street than usual. “We achieved this by building the units as double-storey single units. There were also substantial remedial earthworks that had to take place,” Jansen says.

Commenting on some of the challenges related to the project, he says the existing sewer and stormwater infrastructure posed a challenge as a result of the residents’ use of the current infrastructure, which resulted in sewer blockages and debris blocking the stormwater system.

This required the design of a more robust and higher level of service infrastructure than what would be the norm for the services related to such housing projects, which are provided by local government – in this case the City of Cape Town.

In addition, Jansen says the water table can be shallow during winter periods. The Jakkelsvlei canal is on southern and eastern boundaries along the N2 and N7 respectively.

Therefore, the proposed site had to be raised to above the 1:100 flood lines.

“The Bluegum road extension, which crosses the Jakkelsvlei canal and intersects with the N7 was designed and built as part of Phase 3A. This canal crossing comprised three barrels of 3.6 m × 3 m box culverts, which had to accommodate the 1:100 major storm flow along the Jakkelsvlei canal,” he explains.

The next step for Gibb is to appoint a contractor for Phase 3C.

Jansen says Gibb will be involved in the day-to-day monitoring of the con- tractor’s work on site, adding that Gibb’s involvement in the project is through turnkey contractor, Sobambisana Community Developments.