Pharaonic barays too difficult to maintain are no more built but simple dam bridges across rivers. Furthermore these dam bridges had the advantage to let the traffic cross the rivers in all seasons.

One of the most impressive of these dam bridges, Spean Praptos (80 meters long), still exist supporting the road between Angkor Thom and Sambaur Pré Kuk.
 

Finally, let us mention that the only ship canal clearly spotted up to now (outside of the network which was running in Angkor Thom), is the one leading to Tonlé Sap from the sandstone quarries of Beng Melea. It is supposed that the materials were then carried on the Siemreap river to Angkor.