Cofferdam is a temporary structure which helps to carry out the construction work under reasonable dry condition. Now, what is sandbag? A sandbag is nothing but a bag filled with sand and clay. When these sandbags are used to make a cofferdam, it is known as sandbag cofferdam.
In this system, at first, empty bags or empty cement bags are collected as required. Then they are partially filled with mixture of clay and sand. Next partially filled bags are laid in courses just like masonry work and at last empty space between bags is filled with puddle to make them water-tight.
It has been observed that sandbag cofferdam can withstand the swift of water currents successfully. Side slope of the cofferdam is very steep as sandbags can even maintain verticle face.