Lusip (Lower Usutu Shareholder Irrigation Project) Project, situated near Siphofaneni, Swaziland consists of three dams to form an off-river storage reservoir.

The first structure, Mhalatusane Dam, is a 43m high Roller Compacted Concrete Dam (RCC), with a 435m crest Length. Second Structure, Galome Dam, is a 35m Rock-Fill Clay-Core Dam (RFCC) with a 512m long crest length. During construction the river diversion works consisted of channels, a cofferdam and a training wall where the Main Contractor trained their personnel and honed their dam building skills.

The completed reservoir has a capacity of 155 million m³ that will be diverted from wet season flood flows into the Lower Usuthu River for the irrigation of a total area of 11 500 ha.

Lusip Project Instrumentation consists of the following:

• Vibrating Wire Foundation Piezometers for measuring pore pressure.
• Vibrating Wire Embankment Piezometers for measuring pore pressure.
• Data Acquisition System CR800/1000 (Valve House).
• Vibrating Wire Pendulums-Inverted and Standard.

Instruments installed in and around the Dam Embankment are intended to monitor:

• Tilt of the Dam;
• Measuring movement over the induced joints;
• Stresses and strain of the concrete;
• Total downstream seepage;
• Pore pressure build-up in foundation;
• Lake level water height.

Installed Instruments Specification:

Pendulums (RCC)

• Geokon Vibrating Wire Pendulum Model 6850A

Piezometers (Foundation, Embankment, crump weir, lake level)

• Geokon Vibrating Wire Model 4500S

Data Acquisition System CR800/1000 (Valve House)

• Geokon Micro-1000 Data logger Model 8021

• Geokon Single-Channel Data Logger LC-2 Series Model 8002-1(A)

• Geokon Multiplexer (MUX) Model 8032

Designers: N/A

Consulting Engineers: CGI Joint Venture

Contractors: Concor Roads & Earthworks