Ezulwini Sustainable Water Project

This project required a 15ML Reservoir to be constructed within a mountainside in Eswatini – Ezulwini.

Excavating into the mountainside to create a platform for the reservoir had its own challenges and it has also left a safety risk to the reservoir.

Investigations were done on the high wall left behind the reservoir after the platform construction and the result was that, over time, the high wall will slip into the reservoir and could cause damage to the structure.

Esor’s Geotechnical department was called in and together with the engineers on the project, Aurecon Consultants came up with a solution to protect the high wall from slipping and causing possible damage to the reservoir.

Two benched cuts of approximately 8m high were excavated and supported with 10m to 13m long G25 galvanised soil nails with 150mm thick shotcrete reinforced with Ref. 395 welded steel mesh.

Project value at Tender: R 9 474 289

Duration: 5 Months

Rehabilitation of Mananga Hydrometric Gauging Station

The Komati River flows through South Africa, Eswatini and Mozambique. It is 480 km long, with a drainage basin of around 50,000 km². The Komati River flows from Eswatini into South Africa at the Mananga Border Post and the Mananga Hydrometric Gauging Station is located in Eswatini approximately 2 km upstream of the border. The existing weir is a concrete structure with a total crest length of 87 m and an average height of 6 metres.

The purpose of the gauging station is to monitor cross-border flows between Eswatini and South Africa.

The Scope of Works comprised

• Construction of a 15m long low horizontal crump notch (253.3 masl) near the right riverbank
• Construction of a 30m long higher horizontal crump (253.6 masl) in the middle of the river
• Non-gauging reinforced concrete walls 48 metres long in total flanking the gauging surfaces
• Construction of a 4.7m wide fishway
• Installation of new instrumentation including water quality and rainfall meters

Esor Construction and Raubex Construction formed a Joint Venture in August 2021 to execute the works on behalf of the Komati Basin Water Authority. The Contract was awarded to the Joint Venture in October 2021, with works commencing immediately thereafter. The works were successfully completed in December 2022