The 93 metre high and 2,720 metre long Klong Tha Dan Dam, deigned for irrigation on the Nakon Nayok River, will be the largest Roller-Compacted Concrete dam in the world by volume of concrete used, at 5 million cubic metres. The US$143 million scheme is scheduled for completion in 2004.

The project, designed by Coyne & Bellier, consists of two RCC dams and a clay core saddle dam. Together they will have a water storage capacity of 224 million cubic meters.

The instrumentation for the RCC dams consists of inverted and direct pendulums, observation wells, vibrating wire jointmeters, survey points, piezometers, thermocouples and seepage flow meters. For the saddle dam the consultants selected vibrating wire piezometers, combined inclinometer and magnetic extensometer installations, observation wells, survey points and seepage flow meters.

All the instrumentation has been supplied by Soil Instruments and the installation is being carried out by Soil Instruments’ distributor in Thailand, Research Equipment.

This project is being constructed at the King of Thailand’s initiative. In a speech in Dec 1993 he stated, “…The construction of the dam, only the dam itself and the adjacent system (water transport), will provide the solution to much of the problem.”

Some of the benefits of this project will be:

• Water supply for irrigation to 74,000 acres.
• Reduction of flooding by 35%.
• 16 million cubic metres of water supply to the surrounding districts.
• Decrease of soil surface acidity by irrigated waters.
• Expected fish harvest of 58 tonnes per year.
• Development as a tourist destination.