Clough in a joint venture with Christiani & Nielsen, completed the Construction contract for the Ord River Diversion Dam at Kununurra in Western Australia – harnessing the massive volume of water from the Ord River for the state’s agriculture, supporting WA’s farmers as part of the Ord Irrigation Scheme.

The dam consisted of a barrage with a spillway 335 metres long incorporating 20 radial gates manufactured in Perth and assembled on site. These were each 15 metres wide and 11.3 metres high, weighing 96.5 tonnes and were installed between reinforced concrete piers on a concrete sill keyed onto a quartzite bar in the river, named Bandicoot Bar.

The dam also comprised concrete abutments and a precast prestressed bridge spanning the spillway carrying a 6.7m wide roadway. The roadway over the Ord River Diversion Dam used the same pre-stressed concrete beams utilised for the Narrows Bridge delivered in 1959 by the same joint venture, Christiani Nielsen & Clough (CN&C).

All construction materials except concrete aggregates were shipped from Fremantle to the port of Wyndham then transported 100 km by road to the dam site. The State Shipping Service vessel, SS Dulverton, was converted to carry bulk cement in 1,400 tonne loads, totalling 15,000 tonnes. A total of 41,000 cubic metres of concrete was used for the dam while 350,000 cubic metres of fill was used to construct 4.8km of levee banks and miscellaneous earthworks.

The Ord River Diversion Dam represented the first major civil engineering project constructed by private enterprise for the Public Works Department of Western Australia and the first major barrage with radial gates built in Australia. 

The construction was considered a significant technical achievement, given the remoteness of the site, communications and difficult climatic conditions with sudden river flows.

In 2013, the Ord River Diversion Dam was awarded a national Engineering Heritage Marker by Engineering Heritage Australia.