Emergency Drain Improvements And Safety On Main Road – P30

The KwaZulu-Natal Department of Transport have embarked on a project of rehabilitating and maintaining provincial roads in order to allow the KwaZulu-Natal Road Network to fulfil its core function of access and mobility to various parts of the province.

During a routine inspection of Main Road P30, it had been identified that the pipe culvert structure at Km +- 15 was unstable. Upon closer inspection, it was noted that this structure is in a poor condition and poses a safety threat to all road users. Emergency safety and drainage improvement work was needed to be carried out on Main Road P30 which involved the replacement of the pipe culverts as well as the construction of new concrete headwalls and guardrails.

Figure 1 – Existing Drainage Systems

Figure 2 – Locality Plan Of Main Road 30 (P30) Shown.

Main road 30 (P30), otherwise known as the R74 serves as an important conduit for traffic travelling between Ladysmith and Bergville

A large water catchment along the R74 results in water flowing across the road at Km +- 15. This has resulted in the need for drainage structures to be built at this point on the road.

The existing drainage structure has proved to be inadequate to facilitate the current volume of water flowing across the road, Nankhoo Consulting Engineers had been appointed as the Civil Engineering Consultants to undertake the Design and Construction supervision of the drainage improvements of Main Road P30.

The purpose of the project was to design a structure that would be able to accommodate the large volume of water flowing from the catchment to the road.

The project specifications are as follows:

  • 5 no. 1050mm Ø pipe culverts at 450mm spacing.
  • A retaining wall 3300mm high at the inlet side.
  • A retaining wall 5850mm high at the outlet side.
  • Wingwalls protruding from each retaining wall.
  • Gabion baskets sitting on the base of each retaining wall to prevent scouring.

Figure 3 – New Pipe Converts As Per Required Size Shown.

Minor delays due to inclement weather were worked around, and the project was successfully completed in the allotted time. The accompanying photograph shows the impressive structure, that will ensure the safe use of the R74 for many years to come.

Figure 3 – Structure Shown At End Stage Of Construction..